August 2021 - Kernel - mailweb.openeuler.org

[PATCH 1/9] mm: add Kernel Electric-Fence infrastructure
by 1415317271＠qq.com 18 Aug '21

18 Aug '21

From: Alexander Potapenko <glider(a)google.com> Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7. This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. This series enables KFENCE for the x86 and arm64 architectures, and adds KFENCE hooks to the SLAB and SLUB allocators. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, the next allocation through the main allocator (SLAB or SLUB) returns a guarded allocation from the KFENCE object pool. At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. The KFENCE memory pool is of fixed size, and if the pool is exhausted no further KFENCE allocations occur. The default config is conservative with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB pages). We have verified by running synthetic benchmarks (sysbench I/O, hackbench) and production server-workload benchmarks that a kernel with KFENCE (using sample intervals 100-500ms) is performance-neutral compared to a non-KFENCE baseline kernel. KFENCE is inspired by GWP-ASan [1], a userspace tool with similar properties. The name "KFENCE" is a homage to the Electric Fence Malloc Debugger [2]. For more details, see Documentation/dev-tools/kfence.rst added in the series -- also viewable here: https://raw.githubusercontent.com/google/kasan/kfence/Documentation/dev-too… [1] http://llvm.org/docs/GwpAsan.html [2] https://linux.die.net/man/3/efence This patch (of 9): This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. To detect out-of-bounds writes to memory within the object's page itself, KFENCE also uses pattern-based redzones. The following figure illustrates the page layout: ---+-----------+-----------+-----------+-----------+-----------+--- | xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx | | xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx | | x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x | | xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx | | xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx | | xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx | ---+-----------+-----------+-----------+-----------+-----------+--- Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, a guarded allocation from the KFENCE object pool is returned to the main allocator (SLAB or SLUB). At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. To date, we have verified by running synthetic benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE is performance-neutral compared to the non-KFENCE baseline. For more details, see Documentation/dev-tools/kfence.rst (added later in the series). [elver(a)google.com: fix parameter description for kfence_object_start()] Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com [elver(a)google.com: avoid stalling work queue task without allocations] Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJ… Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com [elver(a)google.com: fix potential deadlock due to wake_up()] Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com [elver(a)google.com: add option to use KFENCE without static keys] Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com [elver(a)google.com: add missing copyright and description headers] Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com Signed-off-by: Marco Elver <elver(a)google.com> Signed-off-by: Alexander Potapenko <glider(a)google.com> Reviewed-by: Dmitry Vyukov <dvyukov(a)google.com> Reviewed-by: SeongJae Park <sjpark(a)amazon.de> Co-developed-by: Marco Elver <elver(a)google.com> Reviewed-by: Jann Horn <jannh(a)google.com> Cc: "H. Peter Anvin" <hpa(a)zytor.com> Cc: Paul E. McKenney <paulmck(a)kernel.org> Cc: Andrey Konovalov <andreyknvl(a)google.com> Cc: Andrey Ryabinin <aryabinin(a)virtuozzo.com> Cc: Andy Lutomirski <luto(a)kernel.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: Catalin Marinas <catalin.marinas(a)arm.com> Cc: Christopher Lameter <cl(a)linux.com> Cc: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: David Rientjes <rientjes(a)google.com> Cc: Eric Dumazet <edumazet(a)google.com> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: Hillf Danton <hdanton(a)sina.com> Cc: Ingo Molnar <mingo(a)redhat.com> Cc: Jonathan Corbet <corbet(a)lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim(a)lge.com> Cc: Joern Engel <joern(a)purestorage.com> Cc: Kees Cook <keescook(a)chromium.org> Cc: Mark Rutland <mark.rutland(a)arm.com> Cc: Pekka Enberg <penberg(a)kernel.org> Cc: Peter Zijlstra <peterz(a)infradead.org> Cc: Thomas Gleixner <tglx(a)linutronix.de> Cc: Vlastimil Babka <vbabka(a)suse.cz> Cc: Will Deacon <will(a)kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds(a)linux-foundation.org> Signed-off-by: Yingjie Shang <1415317271(a)qq.com> Reviewed-by: Bixuan Cui <cuibixuan(a)huawei.com> --- include/linux/kfence.h | 216 +++++++++++ init/main.c | 3 + lib/Kconfig.debug | 1 + lib/Kconfig.kfence | 67 ++++ mm/Makefile | 1 + mm/kfence/Makefile | 3 + mm/kfence/core.c | 840 +++++++++++++++++++++++++++++++++++++++++ mm/kfence/kfence.h | 113 ++++++ mm/kfence/report.c | 240 ++++++++++++ 9 files changed, 1484 insertions(+) create mode 100644 include/linux/kfence.h create mode 100644 lib/Kconfig.kfence create mode 100644 mm/kfence/Makefile create mode 100644 mm/kfence/core.c create mode 100644 mm/kfence/kfence.h create mode 100644 mm/kfence/report.c diff --git a/include/linux/kfence.h b/include/linux/kfence.h new file mode 100644 index 000000000000..81f3911cb298 --- /dev/null +++ b/include/linux/kfence.h @@ -0,0 +1,216 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Kernel Electric-Fence (KFENCE). Public interface for allocator and fault + * handler integration. For more info see Documentation/dev-tools/kfence.rst. + * + * Copyright (C) 2020, Google LLC. + */ + +#ifndef _LINUX_KFENCE_H +#define _LINUX_KFENCE_H + +#include <linux/mm.h> +#include <linux/types.h> + +#ifdef CONFIG_KFENCE + +/* + * We allocate an even number of pages, as it simplifies calculations to map + * address to metadata indices; effectively, the very first page serves as an + * extended guard page, but otherwise has no special purpose. + */ +#define KFENCE_POOL_SIZE ((CONFIG_KFENCE_NUM_OBJECTS + 1) * 2 * PAGE_SIZE) +extern char *__kfence_pool; + +#ifdef CONFIG_KFENCE_STATIC_KEYS +#include <linux/static_key.h> +DECLARE_STATIC_KEY_FALSE(kfence_allocation_key); +#else +#include <linux/atomic.h> +extern atomic_t kfence_allocation_gate; +#endif + +/** + * is_kfence_address() - check if an address belongs to KFENCE pool + * @addr: address to check + * + * Return: true or false depending on whether the address is within the KFENCE + * object range. + * + * KFENCE objects live in a separate page range and are not to be intermixed + * with regular heap objects (e.g. KFENCE objects must never be added to the + * allocator freelists). Failing to do so may and will result in heap + * corruptions, therefore is_kfence_address() must be used to check whether + * an object requires specific handling. + * + * Note: This function may be used in fast-paths, and is performance critical. + * Future changes should take this into account; for instance, we want to avoid + * introducing another load and therefore need to keep KFENCE_POOL_SIZE a + * constant (until immediate patching support is added to the kernel). + */ +static __always_inline bool is_kfence_address(const void *addr) +{ + /* + * The non-NULL check is required in case the __kfence_pool pointer was + * never initialized; keep it in the slow-path after the range-check. + */ + return unlikely((unsigned long)((char *)addr - __kfence_pool) < KFENCE_POOL_SIZE && addr); +} + +/** + * kfence_alloc_pool() - allocate the KFENCE pool via memblock + */ +void __init kfence_alloc_pool(void); + +/** + * kfence_init() - perform KFENCE initialization at boot time + * + * Requires that kfence_alloc_pool() was called before. This sets up the + * allocation gate timer, and requires that workqueues are available. + */ +void __init kfence_init(void); + +/** + * kfence_shutdown_cache() - handle shutdown_cache() for KFENCE objects + * @s: cache being shut down + * + * Before shutting down a cache, one must ensure there are no remaining objects + * allocated from it. Because KFENCE objects are not referenced from the cache + * directly, we need to check them here. + * + * Note that shutdown_cache() is internal to SL*B, and kmem_cache_destroy() does + * not return if allocated objects still exist: it prints an error message and + * simply aborts destruction of a cache, leaking memory. + * + * If the only such objects are KFENCE objects, we will not leak the entire + * cache, but instead try to provide more useful debug info by making allocated + * objects "zombie allocations". Objects may then still be used or freed (which + * is handled gracefully), but usage will result in showing KFENCE error reports + * which include stack traces to the user of the object, the original allocation + * site, and caller to shutdown_cache(). + */ +void kfence_shutdown_cache(struct kmem_cache *s); + +/* + * Allocate a KFENCE object. Allocators must not call this function directly, + * use kfence_alloc() instead. + */ +void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags); + +/** + * kfence_alloc() - allocate a KFENCE object with a low probability + * @s: struct kmem_cache with object requirements + * @size: exact size of the object to allocate (can be less than @s->size + * e.g. for kmalloc caches) + * @flags: GFP flags + * + * Return: + * * NULL - must proceed with allocating as usual, + * * non-NULL - pointer to a KFENCE object. + * + * kfence_alloc() should be inserted into the heap allocation fast path, + * allowing it to transparently return KFENCE-allocated objects with a low + * probability using a static branch (the probability is controlled by the + * kfence.sample_interval boot parameter). + */ +static __always_inline void *kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) +{ +#ifdef CONFIG_KFENCE_STATIC_KEYS + if (static_branch_unlikely(&kfence_allocation_key)) +#else + if (unlikely(!atomic_read(&kfence_allocation_gate))) +#endif + return __kfence_alloc(s, size, flags); + return NULL; +} + +/** + * kfence_ksize() - get actual amount of memory allocated for a KFENCE object + * @addr: pointer to a heap object + * + * Return: + * * 0 - not a KFENCE object, must call __ksize() instead, + * * non-0 - this many bytes can be accessed without causing a memory error. + * + * kfence_ksize() returns the number of bytes requested for a KFENCE object at + * allocation time. This number may be less than the object size of the + * corresponding struct kmem_cache. + */ +size_t kfence_ksize(const void *addr); + +/** + * kfence_object_start() - find the beginning of a KFENCE object + * @addr: address within a KFENCE-allocated object + * + * Return: address of the beginning of the object. + * + * SL[AU]B-allocated objects are laid out within a page one by one, so it is + * easy to calculate the beginning of an object given a pointer inside it and + * the object size. The same is not true for KFENCE, which places a single + * object at either end of the page. This helper function is used to find the + * beginning of a KFENCE-allocated object. + */ +void *kfence_object_start(const void *addr); + +/** + * __kfence_free() - release a KFENCE heap object to KFENCE pool + * @addr: object to be freed + * + * Requires: is_kfence_address(addr) + * + * Release a KFENCE object and mark it as freed. + */ +void __kfence_free(void *addr); + +/** + * kfence_free() - try to release an arbitrary heap object to KFENCE pool + * @addr: object to be freed + * + * Return: + * * false - object doesn't belong to KFENCE pool and was ignored, + * * true - object was released to KFENCE pool. + * + * Release a KFENCE object and mark it as freed. May be called on any object, + * even non-KFENCE objects, to simplify integration of the hooks into the + * allocator's free codepath. The allocator must check the return value to + * determine if it was a KFENCE object or not. + */ +static __always_inline __must_check bool kfence_free(void *addr) +{ + if (!is_kfence_address(addr)) + return false; + __kfence_free(addr); + return true; +} + +/** + * kfence_handle_page_fault() - perform page fault handling for KFENCE pages + * @addr: faulting address + * + * Return: + * * false - address outside KFENCE pool, + * * true - page fault handled by KFENCE, no additional handling required. + * + * A page fault inside KFENCE pool indicates a memory error, such as an + * out-of-bounds access, a use-after-free or an invalid memory access. In these + * cases KFENCE prints an error message and marks the offending page as + * present, so that the kernel can proceed. + */ +bool __must_check kfence_handle_page_fault(unsigned long addr); + +#else /* CONFIG_KFENCE */ + +static inline bool is_kfence_address(const void *addr) { return false; } +static inline void kfence_alloc_pool(void) { } +static inline void kfence_init(void) { } +static inline void kfence_shutdown_cache(struct kmem_cache *s) { } +static inline void *kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) { return NULL; } +static inline size_t kfence_ksize(const void *addr) { return 0; } +static inline void *kfence_object_start(const void *addr) { return NULL; } +static inline void __kfence_free(void *addr) { } +static inline bool __must_check kfence_free(void *addr) { return false; } +static inline bool __must_check kfence_handle_page_fault(unsigned long addr) { return false; } + +#endif + +#endif /* _LINUX_KFENCE_H */ diff --git a/init/main.c b/init/main.c index fc0277a9e7a3..2d027dc11b10 100644 --- a/init/main.c +++ b/init/main.c @@ -40,6 +40,7 @@ #include <linux/security.h> #include <linux/smp.h> #include <linux/profile.h> +#include <linux/kfence.h> #include <linux/rcupdate.h> #include <linux/moduleparam.h> #include <linux/kallsyms.h> @@ -828,6 +829,7 @@ static void __init mm_init(void) */ page_ext_init_flatmem(); init_debug_pagealloc(); + kfence_alloc_pool(); report_meminit(); mem_init(); kmem_cache_init(); @@ -956,6 +958,7 @@ asmlinkage __visible void __init __no_sanitize_address start_kernel(void) hrtimers_init(); softirq_init(); timekeeping_init(); + kfence_init(); /* * For best initial stack canary entropy, prepare it after: diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 799e49a29797..29e64b4cd412 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -878,6 +878,7 @@ config DEBUG_STACKOVERFLOW If in doubt, say "N". source "lib/Kconfig.kasan" +source "lib/Kconfig.kfence" endmenu # "Memory Debugging" diff --git a/lib/Kconfig.kfence b/lib/Kconfig.kfence new file mode 100644 index 000000000000..b88ac9d6b2e6 --- /dev/null +++ b/lib/Kconfig.kfence @@ -0,0 +1,67 @@ +# SPDX-License-Identifier: GPL-2.0-only + +config HAVE_ARCH_KFENCE + bool + +menuconfig KFENCE + bool "KFENCE: low-overhead sampling-based memory safety error detector" + depends on HAVE_ARCH_KFENCE && !KASAN && (SLAB || SLUB) + select STACKTRACE + help + KFENCE is a low-overhead sampling-based detector of heap out-of-bounds + access, use-after-free, and invalid-free errors. KFENCE is designed + to have negligible cost to permit enabling it in production + environments. + + Note that, KFENCE is not a substitute for explicit testing with tools + such as KASAN. KFENCE can detect a subset of bugs that KASAN can + detect, albeit at very different performance profiles. If you can + afford to use KASAN, continue using KASAN, for example in test + environments. If your kernel targets production use, and cannot + enable KASAN due to its cost, consider using KFENCE. + +if KFENCE + +config KFENCE_STATIC_KEYS + bool "Use static keys to set up allocations" + default y + depends on JUMP_LABEL # To ensure performance, require jump labels + help + Use static keys (static branches) to set up KFENCE allocations. Using + static keys is normally recommended, because it avoids a dynamic + branch in the allocator's fast path. However, with very low sample + intervals, or on systems that do not support jump labels, a dynamic + branch may still be an acceptable performance trade-off. + +config KFENCE_SAMPLE_INTERVAL + int "Default sample interval in milliseconds" + default 100 + help + The KFENCE sample interval determines the frequency with which heap + allocations will be guarded by KFENCE. May be overridden via boot + parameter "kfence.sample_interval". + + Set this to 0 to disable KFENCE by default, in which case only + setting "kfence.sample_interval" to a non-zero value enables KFENCE. + +config KFENCE_NUM_OBJECTS + int "Number of guarded objects available" + range 1 65535 + default 255 + help + The number of guarded objects available. For each KFENCE object, 2 + pages are required; with one containing the object and two adjacent + ones used as guard pages. + +config KFENCE_STRESS_TEST_FAULTS + int "Stress testing of fault handling and error reporting" if EXPERT + default 0 + help + The inverse probability with which to randomly protect KFENCE object + pages, resulting in spurious use-after-frees. The main purpose of + this option is to stress test KFENCE with concurrent error reports + and allocations/frees. A value of 0 disables stress testing logic. + + Only for KFENCE testing; set to 0 if you are not a KFENCE developer. + +endif # KFENCE diff --git a/mm/Makefile b/mm/Makefile index 2b1991759835..3d81a67d66a2 100644 --- a/mm/Makefile +++ b/mm/Makefile @@ -82,6 +82,7 @@ obj-$(CONFIG_PAGE_POISONING) += page_poison.o obj-$(CONFIG_SLAB) += slab.o obj-$(CONFIG_SLUB) += slub.o obj-$(CONFIG_KASAN) += kasan/ +obj-$(CONFIG_KFENCE) += kfence/ obj-$(CONFIG_FAILSLAB) += failslab.o obj-$(CONFIG_MEMORY_HOTPLUG) += memory_hotplug.o obj-$(CONFIG_MEMTEST) += memtest.o diff --git a/mm/kfence/Makefile b/mm/kfence/Makefile new file mode 100644 index 000000000000..d991e9a349f0 --- /dev/null +++ b/mm/kfence/Makefile @@ -0,0 +1,3 @@ +# SPDX-License-Identifier: GPL-2.0 + +obj-$(CONFIG_KFENCE) := core.o report.o diff --git a/mm/kfence/core.c b/mm/kfence/core.c new file mode 100644 index 000000000000..d6a32c13336b --- /dev/null +++ b/mm/kfence/core.c @@ -0,0 +1,840 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KFENCE guarded object allocator and fault handling. + * + * Copyright (C) 2020, Google LLC. + */ + +#define pr_fmt(fmt) "kfence: " fmt + +#include <linux/atomic.h> +#include <linux/bug.h> +#include <linux/debugfs.h> +#include <linux/kcsan-checks.h> +#include <linux/kfence.h> +#include <linux/list.h> +#include <linux/lockdep.h> +#include <linux/memblock.h> +#include <linux/moduleparam.h> +#include <linux/random.h> +#include <linux/rcupdate.h> +#include <linux/seq_file.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/string.h> + +#include <asm/kfence.h> + +#include "kfence.h" + +/* Disables KFENCE on the first warning assuming an irrecoverable error. */ +#define KFENCE_WARN_ON(cond) \ + ({ \ + const bool __cond = WARN_ON(cond); \ + if (unlikely(__cond)) \ + WRITE_ONCE(kfence_enabled, false); \ + __cond; \ + }) + +/* === Data ================================================================= */ + +static bool kfence_enabled __read_mostly; + +static unsigned long kfence_sample_interval __read_mostly = CONFIG_KFENCE_SAMPLE_INTERVAL; + +#ifdef MODULE_PARAM_PREFIX +#undef MODULE_PARAM_PREFIX +#endif +#define MODULE_PARAM_PREFIX "kfence." + +static int param_set_sample_interval(const char *val, const struct kernel_param *kp) +{ + unsigned long num; + int ret = kstrtoul(val, 0, &num); + + if (ret < 0) + return ret; + + if (!num) /* Using 0 to indicate KFENCE is disabled. */ + WRITE_ONCE(kfence_enabled, false); + else if (!READ_ONCE(kfence_enabled) && system_state != SYSTEM_BOOTING) + return -EINVAL; /* Cannot (re-)enable KFENCE on-the-fly. */ + + *((unsigned long *)kp->arg) = num; + return 0; +} + +static int param_get_sample_interval(char *buffer, const struct kernel_param *kp) +{ + if (!READ_ONCE(kfence_enabled)) + return sprintf(buffer, "0\n"); + + return param_get_ulong(buffer, kp); +} + +static const struct kernel_param_ops sample_interval_param_ops = { + .set = param_set_sample_interval, + .get = param_get_sample_interval, +}; +module_param_cb(sample_interval, &sample_interval_param_ops, &kfence_sample_interval, 0600); + +/* The pool of pages used for guard pages and objects. */ +char *__kfence_pool __ro_after_init; +EXPORT_SYMBOL(__kfence_pool); /* Export for test modules. */ + +/* + * Per-object metadata, with one-to-one mapping of object metadata to + * backing pages (in __kfence_pool). + */ +static_assert(CONFIG_KFENCE_NUM_OBJECTS > 0); +struct kfence_metadata kfence_metadata[CONFIG_KFENCE_NUM_OBJECTS]; + +/* Freelist with available objects. */ +static struct list_head kfence_freelist = LIST_HEAD_INIT(kfence_freelist); +static DEFINE_RAW_SPINLOCK(kfence_freelist_lock); /* Lock protecting freelist. */ + +#ifdef CONFIG_KFENCE_STATIC_KEYS +/* The static key to set up a KFENCE allocation. */ +DEFINE_STATIC_KEY_FALSE(kfence_allocation_key); +#endif + +/* Gates the allocation, ensuring only one succeeds in a given period. */ +atomic_t kfence_allocation_gate = ATOMIC_INIT(1); + +/* Statistics counters for debugfs. */ +enum kfence_counter_id { + KFENCE_COUNTER_ALLOCATED, + KFENCE_COUNTER_ALLOCS, + KFENCE_COUNTER_FREES, + KFENCE_COUNTER_ZOMBIES, + KFENCE_COUNTER_BUGS, + KFENCE_COUNTER_COUNT, +}; +static atomic_long_t counters[KFENCE_COUNTER_COUNT]; +static const char *const counter_names[] = { + [KFENCE_COUNTER_ALLOCATED] = "currently allocated", + [KFENCE_COUNTER_ALLOCS] = "total allocations", + [KFENCE_COUNTER_FREES] = "total frees", + [KFENCE_COUNTER_ZOMBIES] = "zombie allocations", + [KFENCE_COUNTER_BUGS] = "total bugs", +}; +static_assert(ARRAY_SIZE(counter_names) == KFENCE_COUNTER_COUNT); + +/* === Internals ============================================================ */ + +static bool kfence_protect(unsigned long addr) +{ + return !KFENCE_WARN_ON(!kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), true)); +} + +static bool kfence_unprotect(unsigned long addr) +{ + return !KFENCE_WARN_ON(!kfence_protect_page(ALIGN_DOWN(addr, PAGE_SIZE), false)); +} + +static inline struct kfence_metadata *addr_to_metadata(unsigned long addr) +{ + long index; + + /* The checks do not affect performance; only called from slow-paths. */ + + if (!is_kfence_address((void *)addr)) + return NULL; + + /* + * May be an invalid index if called with an address at the edge of + * __kfence_pool, in which case we would report an "invalid access" + * error. + */ + index = (addr - (unsigned long)__kfence_pool) / (PAGE_SIZE * 2) - 1; + if (index < 0 || index >= CONFIG_KFENCE_NUM_OBJECTS) + return NULL; + + return &kfence_metadata[index]; +} + +static inline unsigned long metadata_to_pageaddr(const struct kfence_metadata *meta) +{ + unsigned long offset = (meta - kfence_metadata + 1) * PAGE_SIZE * 2; + unsigned long pageaddr = (unsigned long)&__kfence_pool[offset]; + + /* The checks do not affect performance; only called from slow-paths. */ + + /* Only call with a pointer into kfence_metadata. */ + if (KFENCE_WARN_ON(meta < kfence_metadata || + meta >= kfence_metadata + CONFIG_KFENCE_NUM_OBJECTS)) + return 0; + + /* + * This metadata object only ever maps to 1 page; verify that the stored + * address is in the expected range. + */ + if (KFENCE_WARN_ON(ALIGN_DOWN(meta->addr, PAGE_SIZE) != pageaddr)) + return 0; + + return pageaddr; +} + +/* + * Update the object's metadata state, including updating the alloc/free stacks + * depending on the state transition. + */ +static noinline void metadata_update_state(struct kfence_metadata *meta, + enum kfence_object_state next) +{ + struct kfence_track *track = + next == KFENCE_OBJECT_FREED ? &meta->free_track : &meta->alloc_track; + + lockdep_assert_held(&meta->lock); + + /* + * Skip over 1 (this) functions; noinline ensures we do not accidentally + * skip over the caller by never inlining. + */ + track->num_stack_entries = stack_trace_save(track->stack_entries, KFENCE_STACK_DEPTH, 1); + track->pid = task_pid_nr(current); + + /* + * Pairs with READ_ONCE() in + * kfence_shutdown_cache(), + * kfence_handle_page_fault(). + */ + WRITE_ONCE(meta->state, next); +} + +/* Write canary byte to @addr. */ +static inline bool set_canary_byte(u8 *addr) +{ + *addr = KFENCE_CANARY_PATTERN(addr); + return true; +} + +/* Check canary byte at @addr. */ +static inline bool check_canary_byte(u8 *addr) +{ + if (likely(*addr == KFENCE_CANARY_PATTERN(addr))) + return true; + + atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]); + kfence_report_error((unsigned long)addr, addr_to_metadata((unsigned long)addr), + KFENCE_ERROR_CORRUPTION); + return false; +} + +/* __always_inline this to ensure we won't do an indirect call to fn. */ +static __always_inline void for_each_canary(const struct kfence_metadata *meta, bool (*fn)(u8 *)) +{ + const unsigned long pageaddr = ALIGN_DOWN(meta->addr, PAGE_SIZE); + unsigned long addr; + + lockdep_assert_held(&meta->lock); + + /* + * We'll iterate over each canary byte per-side until fn() returns + * false. However, we'll still iterate over the canary bytes to the + * right of the object even if there was an error in the canary bytes to + * the left of the object. Specifically, if check_canary_byte() + * generates an error, showing both sides might give more clues as to + * what the error is about when displaying which bytes were corrupted. + */ + + /* Apply to left of object. */ + for (addr = pageaddr; addr < meta->addr; addr++) { + if (!fn((u8 *)addr)) + break; + } + + /* Apply to right of object. */ + for (addr = meta->addr + meta->size; addr < pageaddr + PAGE_SIZE; addr++) { + if (!fn((u8 *)addr)) + break; + } +} + +static void *kfence_guarded_alloc(struct kmem_cache *cache, size_t size, gfp_t gfp) +{ + struct kfence_metadata *meta = NULL; + unsigned long flags; + struct page *page; + void *addr; + + /* Try to obtain a free object. */ + raw_spin_lock_irqsave(&kfence_freelist_lock, flags); + if (!list_empty(&kfence_freelist)) { + meta = list_entry(kfence_freelist.next, struct kfence_metadata, list); + list_del_init(&meta->list); + } + raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags); + if (!meta) + return NULL; + + if (unlikely(!raw_spin_trylock_irqsave(&meta->lock, flags))) { + /* + * This is extremely unlikely -- we are reporting on a + * use-after-free, which locked meta->lock, and the reporting + * code via printk calls kmalloc() which ends up in + * kfence_alloc() and tries to grab the same object that we're + * reporting on. While it has never been observed, lockdep does + * report that there is a possibility of deadlock. Fix it by + * using trylock and bailing out gracefully. + */ + raw_spin_lock_irqsave(&kfence_freelist_lock, flags); + /* Put the object back on the freelist. */ + list_add_tail(&meta->list, &kfence_freelist); + raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags); + + return NULL; + } + + meta->addr = metadata_to_pageaddr(meta); + /* Unprotect if we're reusing this page. */ + if (meta->state == KFENCE_OBJECT_FREED) + kfence_unprotect(meta->addr); + + /* + * Note: for allocations made before RNG initialization, will always + * return zero. We still benefit from enabling KFENCE as early as + * possible, even when the RNG is not yet available, as this will allow + * KFENCE to detect bugs due to earlier allocations. The only downside + * is that the out-of-bounds accesses detected are deterministic for + * such allocations. + */ + if (prandom_u32_max(2)) { + /* Allocate on the "right" side, re-calculate address. */ + meta->addr += PAGE_SIZE - size; + meta->addr = ALIGN_DOWN(meta->addr, cache->align); + } + + addr = (void *)meta->addr; + + /* Update remaining metadata. */ + metadata_update_state(meta, KFENCE_OBJECT_ALLOCATED); + /* Pairs with READ_ONCE() in kfence_shutdown_cache(). */ + WRITE_ONCE(meta->cache, cache); + meta->size = size; + for_each_canary(meta, set_canary_byte); + + /* Set required struct page fields. */ + page = virt_to_page(meta->addr); + page->slab_cache = cache; + + raw_spin_unlock_irqrestore(&meta->lock, flags); + + /* Memory initialization. */ + + /* + * We check slab_want_init_on_alloc() ourselves, rather than letting + * SL*B do the initialization, as otherwise we might overwrite KFENCE's + * redzone. + */ + if (unlikely(slab_want_init_on_alloc(gfp, cache))) + memzero_explicit(addr, size); + if (cache->ctor) + cache->ctor(addr); + + if (CONFIG_KFENCE_STRESS_TEST_FAULTS && !prandom_u32_max(CONFIG_KFENCE_STRESS_TEST_FAULTS)) + kfence_protect(meta->addr); /* Random "faults" by protecting the object. */ + + atomic_long_inc(&counters[KFENCE_COUNTER_ALLOCATED]); + atomic_long_inc(&counters[KFENCE_COUNTER_ALLOCS]); + + return addr; +} + +static void kfence_guarded_free(void *addr, struct kfence_metadata *meta, bool zombie) +{ + struct kcsan_scoped_access assert_page_exclusive; + unsigned long flags; + + raw_spin_lock_irqsave(&meta->lock, flags); + + if (meta->state != KFENCE_OBJECT_ALLOCATED || meta->addr != (unsigned long)addr) { + /* Invalid or double-free, bail out. */ + atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]); + kfence_report_error((unsigned long)addr, meta, KFENCE_ERROR_INVALID_FREE); + raw_spin_unlock_irqrestore(&meta->lock, flags); + return; + } + + /* Detect racy use-after-free, or incorrect reallocation of this page by KFENCE. */ + kcsan_begin_scoped_access((void *)ALIGN_DOWN((unsigned long)addr, PAGE_SIZE), PAGE_SIZE, + KCSAN_ACCESS_SCOPED | KCSAN_ACCESS_WRITE | KCSAN_ACCESS_ASSERT, + &assert_page_exclusive); + + if (CONFIG_KFENCE_STRESS_TEST_FAULTS) + kfence_unprotect((unsigned long)addr); /* To check canary bytes. */ + + /* Restore page protection if there was an OOB access. */ + if (meta->unprotected_page) { + kfence_protect(meta->unprotected_page); + meta->unprotected_page = 0; + } + + /* Check canary bytes for memory corruption. */ + for_each_canary(meta, check_canary_byte); + + /* + * Clear memory if init-on-free is set. While we protect the page, the + * data is still there, and after a use-after-free is detected, we + * unprotect the page, so the data is still accessible. + */ + if (!zombie && unlikely(slab_want_init_on_free(meta->cache))) + memzero_explicit(addr, meta->size); + + /* Mark the object as freed. */ + metadata_update_state(meta, KFENCE_OBJECT_FREED); + + raw_spin_unlock_irqrestore(&meta->lock, flags); + + /* Protect to detect use-after-frees. */ + kfence_protect((unsigned long)addr); + + kcsan_end_scoped_access(&assert_page_exclusive); + if (!zombie) { + /* Add it to the tail of the freelist for reuse. */ + raw_spin_lock_irqsave(&kfence_freelist_lock, flags); + KFENCE_WARN_ON(!list_empty(&meta->list)); + list_add_tail(&meta->list, &kfence_freelist); + raw_spin_unlock_irqrestore(&kfence_freelist_lock, flags); + + atomic_long_dec(&counters[KFENCE_COUNTER_ALLOCATED]); + atomic_long_inc(&counters[KFENCE_COUNTER_FREES]); + } else { + /* See kfence_shutdown_cache(). */ + atomic_long_inc(&counters[KFENCE_COUNTER_ZOMBIES]); + } +} + +static void rcu_guarded_free(struct rcu_head *h) +{ + struct kfence_metadata *meta = container_of(h, struct kfence_metadata, rcu_head); + + kfence_guarded_free((void *)meta->addr, meta, false); +} + +static bool __init kfence_init_pool(void) +{ + unsigned long addr = (unsigned long)__kfence_pool; + struct page *pages; + int i; + + if (!__kfence_pool) + return false; + + if (!arch_kfence_init_pool()) + goto err; + + pages = virt_to_page(addr); + + /* + * Set up object pages: they must have PG_slab set, to avoid freeing + * these as real pages. + * + * We also want to avoid inserting kfence_free() in the kfree() + * fast-path in SLUB, and therefore need to ensure kfree() correctly + * enters __slab_free() slow-path. + */ + for (i = 0; i < KFENCE_POOL_SIZE / PAGE_SIZE; i++) { + if (!i || (i % 2)) + continue; + + /* Verify we do not have a compound head page. */ + if (WARN_ON(compound_head(&pages[i]) != &pages[i])) + goto err; + + __SetPageSlab(&pages[i]); + } + + /* + * Protect the first 2 pages. The first page is mostly unnecessary, and + * merely serves as an extended guard page. However, adding one + * additional page in the beginning gives us an even number of pages, + * which simplifies the mapping of address to metadata index. + */ + for (i = 0; i < 2; i++) { + if (unlikely(!kfence_protect(addr))) + goto err; + + addr += PAGE_SIZE; + } + + for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) { + struct kfence_metadata *meta = &kfence_metadata[i]; + + /* Initialize metadata. */ + INIT_LIST_HEAD(&meta->list); + raw_spin_lock_init(&meta->lock); + meta->state = KFENCE_OBJECT_UNUSED; + meta->addr = addr; /* Initialize for validation in metadata_to_pageaddr(). */ + list_add_tail(&meta->list, &kfence_freelist); + + /* Protect the right redzone. */ + if (unlikely(!kfence_protect(addr + PAGE_SIZE))) + goto err; + + addr += 2 * PAGE_SIZE; + } + + return true; + +err: + /* + * Only release unprotected pages, and do not try to go back and change + * page attributes due to risk of failing to do so as well. If changing + * page attributes for some pages fails, it is very likely that it also + * fails for the first page, and therefore expect addr==__kfence_pool in + * most failure cases. + */ + memblock_free_late(__pa(addr), KFENCE_POOL_SIZE - (addr - (unsigned long)__kfence_pool)); + __kfence_pool = NULL; + return false; +} + +/* === DebugFS Interface ==================================================== */ + +static int stats_show(struct seq_file *seq, void *v) +{ + int i; + + seq_printf(seq, "enabled: %i\n", READ_ONCE(kfence_enabled)); + for (i = 0; i < KFENCE_COUNTER_COUNT; i++) + seq_printf(seq, "%s: %ld\n", counter_names[i], atomic_long_read(&counters[i])); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(stats); + +/* + * debugfs seq_file operations for /sys/kernel/debug/kfence/objects. + * start_object() and next_object() return the object index + 1, because NULL is used + * to stop iteration. + */ +static void *start_object(struct seq_file *seq, loff_t *pos) +{ + if (*pos < CONFIG_KFENCE_NUM_OBJECTS) + return (void *)((long)*pos + 1); + return NULL; +} + +static void stop_object(struct seq_file *seq, void *v) +{ +} + +static void *next_object(struct seq_file *seq, void *v, loff_t *pos) +{ + ++*pos; + if (*pos < CONFIG_KFENCE_NUM_OBJECTS) + return (void *)((long)*pos + 1); + return NULL; +} + +static int show_object(struct seq_file *seq, void *v) +{ + struct kfence_metadata *meta = &kfence_metadata[(long)v - 1]; + unsigned long flags; + + raw_spin_lock_irqsave(&meta->lock, flags); + kfence_print_object(seq, meta); + raw_spin_unlock_irqrestore(&meta->lock, flags); + seq_puts(seq, "---------------------------------\n"); + + return 0; +} + +static const struct seq_operations object_seqops = { + .start = start_object, + .next = next_object, + .stop = stop_object, + .show = show_object, +}; + +static int open_objects(struct inode *inode, struct file *file) +{ + return seq_open(file, &object_seqops); +} + +static const struct file_operations objects_fops = { + .open = open_objects, + .read = seq_read, + .llseek = seq_lseek, +}; + +static int __init kfence_debugfs_init(void) +{ + struct dentry *kfence_dir = debugfs_create_dir("kfence", NULL); + + debugfs_create_file("stats", 0444, kfence_dir, NULL, &stats_fops); + debugfs_create_file("objects", 0400, kfence_dir, NULL, &objects_fops); + return 0; +} + +late_initcall(kfence_debugfs_init); + +/* === Allocation Gate Timer ================================================ */ + +/* + * Set up delayed work, which will enable and disable the static key. We need to + * use a work queue (rather than a simple timer), since enabling and disabling a + * static key cannot be done from an interrupt. + * + * Note: Toggling a static branch currently causes IPIs, and here we'll end up + * with a total of 2 IPIs to all CPUs. If this ends up a problem in future (with + * more aggressive sampling intervals), we could get away with a variant that + * avoids IPIs, at the cost of not immediately capturing allocations if the + * instructions remain cached. + */ +static struct delayed_work kfence_timer; +static void toggle_allocation_gate(struct work_struct *work) +{ + if (!READ_ONCE(kfence_enabled)) + return; + + /* Enable static key, and await allocation to happen. */ + atomic_set(&kfence_allocation_gate, 0); +#ifdef CONFIG_KFENCE_STATIC_KEYS + static_branch_enable(&kfence_allocation_key); + /* + * Await an allocation. Timeout after 1 second, in case the kernel stops + * doing allocations, to avoid stalling this worker task for too long. + */ + { + unsigned long end_wait = jiffies + HZ; + + do { + set_current_state(TASK_UNINTERRUPTIBLE); + if (atomic_read(&kfence_allocation_gate) != 0) + break; + schedule_timeout(1); + } while (time_before(jiffies, end_wait)); + __set_current_state(TASK_RUNNING); + } + /* Disable static key and reset timer. */ + static_branch_disable(&kfence_allocation_key); +#endif + schedule_delayed_work(&kfence_timer, msecs_to_jiffies(kfence_sample_interval)); +} +static DECLARE_DELAYED_WORK(kfence_timer, toggle_allocation_gate); + +/* === Public interface ===================================================== */ + +void __init kfence_alloc_pool(void) +{ + if (!kfence_sample_interval) + return; + + __kfence_pool = memblock_alloc(KFENCE_POOL_SIZE, PAGE_SIZE); + + if (!__kfence_pool) + pr_err("failed to allocate pool\n"); +} + +void __init kfence_init(void) +{ + /* Setting kfence_sample_interval to 0 on boot disables KFENCE. */ + if (!kfence_sample_interval) + return; + + if (!kfence_init_pool()) { + pr_err("%s failed\n", __func__); + return; + } + + WRITE_ONCE(kfence_enabled, true); + schedule_delayed_work(&kfence_timer, 0); + pr_info("initialized - using %lu bytes for %d objects", KFENCE_POOL_SIZE, + CONFIG_KFENCE_NUM_OBJECTS); + if (IS_ENABLED(CONFIG_DEBUG_KERNEL)) + pr_cont(" at 0x%px-0x%px\n", (void *)__kfence_pool, + (void *)(__kfence_pool + KFENCE_POOL_SIZE)); + else + pr_cont("\n"); +} + +void kfence_shutdown_cache(struct kmem_cache *s) +{ + unsigned long flags; + struct kfence_metadata *meta; + int i; + + for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) { + bool in_use; + + meta = &kfence_metadata[i]; + + /* + * If we observe some inconsistent cache and state pair where we + * should have returned false here, cache destruction is racing + * with either kmem_cache_alloc() or kmem_cache_free(). Taking + * the lock will not help, as different critical section + * serialization will have the same outcome. + */ + if (READ_ONCE(meta->cache) != s || + READ_ONCE(meta->state) != KFENCE_OBJECT_ALLOCATED) + continue; + + raw_spin_lock_irqsave(&meta->lock, flags); + in_use = meta->cache == s && meta->state == KFENCE_OBJECT_ALLOCATED; + raw_spin_unlock_irqrestore(&meta->lock, flags); + + if (in_use) { + /* + * This cache still has allocations, and we should not + * release them back into the freelist so they can still + * safely be used and retain the kernel's default + * behaviour of keeping the allocations alive (leak the + * cache); however, they effectively become "zombie + * allocations" as the KFENCE objects are the only ones + * still in use and the owning cache is being destroyed. + * + * We mark them freed, so that any subsequent use shows + * more useful error messages that will include stack + * traces of the user of the object, the original + * allocation, and caller to shutdown_cache(). + */ + kfence_guarded_free((void *)meta->addr, meta, /*zombie=*/true); + } + } + + for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) { + meta = &kfence_metadata[i]; + + /* See above. */ + if (READ_ONCE(meta->cache) != s || READ_ONCE(meta->state) != KFENCE_OBJECT_FREED) + continue; + + raw_spin_lock_irqsave(&meta->lock, flags); + if (meta->cache == s && meta->state == KFENCE_OBJECT_FREED) + meta->cache = NULL; + raw_spin_unlock_irqrestore(&meta->lock, flags); + } +} + +void *__kfence_alloc(struct kmem_cache *s, size_t size, gfp_t flags) +{ + /* + * allocation_gate only needs to become non-zero, so it doesn't make + * sense to continue writing to it and pay the associated contention + * cost, in case we have a large number of concurrent allocations. + */ + if (atomic_read(&kfence_allocation_gate) || atomic_inc_return(&kfence_allocation_gate) > 1) + return NULL; + + if (!READ_ONCE(kfence_enabled)) + return NULL; + + if (size > PAGE_SIZE) + return NULL; + + return kfence_guarded_alloc(s, size, flags); +} + +size_t kfence_ksize(const void *addr) +{ + const struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr); + + /* + * Read locklessly -- if there is a race with __kfence_alloc(), this is + * either a use-after-free or invalid access. + */ + return meta ? meta->size : 0; +} + +void *kfence_object_start(const void *addr) +{ + const struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr); + + /* + * Read locklessly -- if there is a race with __kfence_alloc(), this is + * either a use-after-free or invalid access. + */ + return meta ? (void *)meta->addr : NULL; +} + +void __kfence_free(void *addr) +{ + struct kfence_metadata *meta = addr_to_metadata((unsigned long)addr); + + /* + * If the objects of the cache are SLAB_TYPESAFE_BY_RCU, defer freeing + * the object, as the object page may be recycled for other-typed + * objects once it has been freed. meta->cache may be NULL if the cache + * was destroyed. + */ + if (unlikely(meta->cache && (meta->cache->flags & SLAB_TYPESAFE_BY_RCU))) + call_rcu(&meta->rcu_head, rcu_guarded_free); + else + kfence_guarded_free(addr, meta, false); +} + +bool kfence_handle_page_fault(unsigned long addr) +{ + const int page_index = (addr - (unsigned long)__kfence_pool) / PAGE_SIZE; + struct kfence_metadata *to_report = NULL; + enum kfence_error_type error_type; + unsigned long flags; + + if (!is_kfence_address((void *)addr)) + return false; + + if (!READ_ONCE(kfence_enabled)) /* If disabled at runtime ... */ + return kfence_unprotect(addr); /* ... unprotect and proceed. */ + + atomic_long_inc(&counters[KFENCE_COUNTER_BUGS]); + + if (page_index % 2) { + /* This is a redzone, report a buffer overflow. */ + struct kfence_metadata *meta; + int distance = 0; + + meta = addr_to_metadata(addr - PAGE_SIZE); + if (meta && READ_ONCE(meta->state) == KFENCE_OBJECT_ALLOCATED) { + to_report = meta; + /* Data race ok; distance calculation approximate. */ + distance = addr - data_race(meta->addr + meta->size); + } + + meta = addr_to_metadata(addr + PAGE_SIZE); + if (meta && READ_ONCE(meta->state) == KFENCE_OBJECT_ALLOCATED) { + /* Data race ok; distance calculation approximate. */ + if (!to_report || distance > data_race(meta->addr) - addr) + to_report = meta; + } + + if (!to_report) + goto out; + + raw_spin_lock_irqsave(&to_report->lock, flags); + to_report->unprotected_page = addr; + error_type = KFENCE_ERROR_OOB; + + /* + * If the object was freed before we took the look we can still + * report this as an OOB -- the report will simply show the + * stacktrace of the free as well. + */ + } else { + to_report = addr_to_metadata(addr); + if (!to_report) + goto out; + + raw_spin_lock_irqsave(&to_report->lock, flags); + error_type = KFENCE_ERROR_UAF; + /* + * We may race with __kfence_alloc(), and it is possible that a + * freed object may be reallocated. We simply report this as a + * use-after-free, with the stack trace showing the place where + * the object was re-allocated. + */ + } + +out: + if (to_report) { + kfence_report_error(addr, to_report, error_type); + raw_spin_unlock_irqrestore(&to_report->lock, flags); + } else { + /* This may be a UAF or OOB access, but we can't be sure. */ + kfence_report_error(addr, NULL, KFENCE_ERROR_INVALID); + } + + return kfence_unprotect(addr); /* Unprotect and let access proceed. */ +} diff --git a/mm/kfence/kfence.h b/mm/kfence/kfence.h new file mode 100644 index 000000000000..1014060f9707 --- /dev/null +++ b/mm/kfence/kfence.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Kernel Electric-Fence (KFENCE). For more info please see + * Documentation/dev-tools/kfence.rst. + * + * Copyright (C) 2020, Google LLC. + */ + +#ifndef MM_KFENCE_KFENCE_H +#define MM_KFENCE_KFENCE_H + +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include "../slab.h" /* for struct kmem_cache */ + +/* For non-debug builds, avoid leaking kernel pointers into dmesg. */ +#ifdef CONFIG_DEBUG_KERNEL +#define PTR_FMT "%px" +#else +#define PTR_FMT "%p" +#endif + +/* + * Get the canary byte pattern for @addr. Use a pattern that varies based on the + * lower 3 bits of the address, to detect memory corruptions with higher + * probability, where similar constants are used. + */ +#define KFENCE_CANARY_PATTERN(addr) ((u8)0xaa ^ (u8)((unsigned long)(addr) & 0x7)) + +/* Maximum stack depth for reports. */ +#define KFENCE_STACK_DEPTH 64 + +/* KFENCE object states. */ +enum kfence_object_state { + KFENCE_OBJECT_UNUSED, /* Object is unused. */ + KFENCE_OBJECT_ALLOCATED, /* Object is currently allocated. */ + KFENCE_OBJECT_FREED, /* Object was allocated, and then freed. */ +}; + +/* Alloc/free tracking information. */ +struct kfence_track { + pid_t pid; + int num_stack_entries; + unsigned long stack_entries[KFENCE_STACK_DEPTH]; +}; + +/* KFENCE metadata per guarded allocation. */ +struct kfence_metadata { + struct list_head list; /* Freelist node; access under kfence_freelist_lock. */ + struct rcu_head rcu_head; /* For delayed freeing. */ + + /* + * Lock protecting below data; to ensure consistency of the below data, + * since the following may execute concurrently: __kfence_alloc(), + * __kfence_free(), kfence_handle_page_fault(). However, note that we + * cannot grab the same metadata off the freelist twice, and multiple + * __kfence_alloc() cannot run concurrently on the same metadata. + */ + raw_spinlock_t lock; + + /* The current state of the object; see above. */ + enum kfence_object_state state; + + /* + * Allocated object address; cannot be calculated from size, because of + * alignment requirements. + * + * Invariant: ALIGN_DOWN(addr, PAGE_SIZE) is constant. + */ + unsigned long addr; + + /* + * The size of the original allocation. + */ + size_t size; + + /* + * The kmem_cache cache of the last allocation; NULL if never allocated + * or the cache has already been destroyed. + */ + struct kmem_cache *cache; + + /* + * In case of an invalid access, the page that was unprotected; we + * optimistically only store one address. + */ + unsigned long unprotected_page; + + /* Allocation and free stack information. */ + struct kfence_track alloc_track; + struct kfence_track free_track; +}; + +extern struct kfence_metadata kfence_metadata[CONFIG_KFENCE_NUM_OBJECTS]; + +/* KFENCE error types for report generation. */ +enum kfence_error_type { + KFENCE_ERROR_OOB, /* Detected a out-of-bounds access. */ + KFENCE_ERROR_UAF, /* Detected a use-after-free access. */ + KFENCE_ERROR_CORRUPTION, /* Detected a memory corruption on free. */ + KFENCE_ERROR_INVALID, /* Invalid access of unknown type. */ + KFENCE_ERROR_INVALID_FREE, /* Invalid free. */ +}; + +void kfence_report_error(unsigned long address, const struct kfence_metadata *meta, + enum kfence_error_type type); + +void kfence_print_object(struct seq_file *seq, const struct kfence_metadata *meta); + +#endif /* MM_KFENCE_KFENCE_H */ diff --git a/mm/kfence/report.c b/mm/kfence/report.c new file mode 100644 index 000000000000..64f27c8d46a3 --- /dev/null +++ b/mm/kfence/report.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * KFENCE reporting. + * + * Copyright (C) 2020, Google LLC. + */ + +#include <stdarg.h> + +#include <linux/kernel.h> +#include <linux/lockdep.h> +#include <linux/printk.h> +#include <linux/seq_file.h> +#include <linux/stacktrace.h> +#include <linux/string.h> + +#include <asm/kfence.h> + +#include "kfence.h" + +/* Helper function to either print to a seq_file or to console. */ +__printf(2, 3) +static void seq_con_printf(struct seq_file *seq, const char *fmt, ...) +{ + va_list args; + + va_start(args, fmt); + if (seq) + seq_vprintf(seq, fmt, args); + else + vprintk(fmt, args); + va_end(args); +} + +/* + * Get the number of stack entries to skip to get out of MM internals. @type is + * optional, and if set to NULL, assumes an allocation or free stack. + */ +static int get_stack_skipnr(const unsigned long stack_entries[], int num_entries, + const enum kfence_error_type *type) +{ + char buf[64]; + int skipnr, fallback = 0; + bool is_access_fault = false; + + if (type) { + /* Depending on error type, find different stack entries. */ + switch (*type) { + case KFENCE_ERROR_UAF: + case KFENCE_ERROR_OOB: + case KFENCE_ERROR_INVALID: + is_access_fault = true; + break; + case KFENCE_ERROR_CORRUPTION: + case KFENCE_ERROR_INVALID_FREE: + break; + } + } + + for (skipnr = 0; skipnr < num_entries; skipnr++) { + int len = scnprintf(buf, sizeof(buf), "%ps", (void *)stack_entries[skipnr]); + + if (is_access_fault) { + if (!strncmp(buf, KFENCE_SKIP_ARCH_FAULT_HANDLER, len)) + goto found; + } else { + if (str_has_prefix(buf, "kfence_") || str_has_prefix(buf, "__kfence_") || + !strncmp(buf, "__slab_free", len)) { + /* + * In case of tail calls from any of the below + * to any of the above. + */ + fallback = skipnr + 1; + } + + /* Also the *_bulk() variants by only checking prefixes. */ + if (str_has_prefix(buf, "kfree") || + str_has_prefix(buf, "kmem_cache_free") || + str_has_prefix(buf, "__kmalloc") || + str_has_prefix(buf, "kmem_cache_alloc")) + goto found; + } + } + if (fallback < num_entries) + return fallback; +found: + skipnr++; + return skipnr < num_entries ? skipnr : 0; +} + +static void kfence_print_stack(struct seq_file *seq, const struct kfence_metadata *meta, + bool show_alloc) +{ + const struct kfence_track *track = show_alloc ? &meta->alloc_track : &meta->free_track; + + if (track->num_stack_entries) { + /* Skip allocation/free internals stack. */ + int i = get_stack_skipnr(track->stack_entries, track->num_stack_entries, NULL); + + /* stack_trace_seq_print() does not exist; open code our own. */ + for (; i < track->num_stack_entries; i++) + seq_con_printf(seq, " %pS\n", (void *)track->stack_entries[i]); + } else { + seq_con_printf(seq, " no %s stack\n", show_alloc ? "allocation" : "deallocation"); + } +} + +void kfence_print_object(struct seq_file *seq, const struct kfence_metadata *meta) +{ + const int size = abs(meta->size); + const unsigned long start = meta->addr; + const struct kmem_cache *const cache = meta->cache; + + lockdep_assert_held(&meta->lock); + + if (meta->state == KFENCE_OBJECT_UNUSED) { + seq_con_printf(seq, "kfence-#%zd unused\n", meta - kfence_metadata); + return; + } + + seq_con_printf(seq, + "kfence-#%zd [0x" PTR_FMT "-0x" PTR_FMT + ", size=%d, cache=%s] allocated by task %d:\n", + meta - kfence_metadata, (void *)start, (void *)(start + size - 1), size, + (cache && cache->name) ? cache->name : "<destroyed>", meta->alloc_track.pid); + kfence_print_stack(seq, meta, true); + + if (meta->state == KFENCE_OBJECT_FREED) { + seq_con_printf(seq, "\nfreed by task %d:\n", meta->free_track.pid); + kfence_print_stack(seq, meta, false); + } +} + +/* + * Show bytes at @addr that are different from the expected canary values, up to + * @max_bytes. + */ +static void print_diff_canary(unsigned long address, size_t bytes_to_show, + const struct kfence_metadata *meta) +{ + const unsigned long show_until_addr = address + bytes_to_show; + const u8 *cur, *end; + + /* Do not show contents of object nor read into following guard page. */ + end = (const u8 *)(address < meta->addr ? min(show_until_addr, meta->addr) + : min(show_until_addr, PAGE_ALIGN(address))); + + pr_cont("["); + for (cur = (const u8 *)address; cur < end; cur++) { + if (*cur == KFENCE_CANARY_PATTERN(cur)) + pr_cont(" ."); + else if (IS_ENABLED(CONFIG_DEBUG_KERNEL)) + pr_cont(" 0x%02x", *cur); + else /* Do not leak kernel memory in non-debug builds. */ + pr_cont(" !"); + } + pr_cont(" ]"); +} + +void kfence_report_error(unsigned long address, const struct kfence_metadata *meta, + enum kfence_error_type type) +{ + unsigned long stack_entries[KFENCE_STACK_DEPTH] = { 0 }; + int num_stack_entries = stack_trace_save(stack_entries, KFENCE_STACK_DEPTH, 1); + int skipnr = get_stack_skipnr(stack_entries, num_stack_entries, &type); + const ptrdiff_t object_index = meta ? meta - kfence_metadata : -1; + + /* Require non-NULL meta, except if KFENCE_ERROR_INVALID. */ + if (WARN_ON(type != KFENCE_ERROR_INVALID && !meta)) + return; + + if (meta) + lockdep_assert_held(&meta->lock); + /* + * Because we may generate reports in printk-unfriendly parts of the + * kernel, such as scheduler code, the use of printk() could deadlock. + * Until such time that all printing code here is safe in all parts of + * the kernel, accept the risk, and just get our message out (given the + * system might already behave unpredictably due to the memory error). + * As such, also disable lockdep to hide warnings, and avoid disabling + * lockdep for the rest of the kernel. + */ + lockdep_off(); + + pr_err("==================================================================\n"); + /* Print report header. */ + switch (type) { + case KFENCE_ERROR_OOB: { + const bool left_of_object = address < meta->addr; + + pr_err("BUG: KFENCE: out-of-bounds in %pS\n\n", (void *)stack_entries[skipnr]); + pr_err("Out-of-bounds access at 0x" PTR_FMT " (%luB %s of kfence-#%zd):\n", + (void *)address, + left_of_object ? meta->addr - address : address - meta->addr, + left_of_object ? "left" : "right", object_index); + break; + } + case KFENCE_ERROR_UAF: + pr_err("BUG: KFENCE: use-after-free in %pS\n\n", (void *)stack_entries[skipnr]); + pr_err("Use-after-free access at 0x" PTR_FMT " (in kfence-#%zd):\n", + (void *)address, object_index); + break; + case KFENCE_ERROR_CORRUPTION: + pr_err("BUG: KFENCE: memory corruption in %pS\n\n", (void *)stack_entries[skipnr]); + pr_err("Corrupted memory at 0x" PTR_FMT " ", (void *)address); + print_diff_canary(address, 16, meta); + pr_cont(" (in kfence-#%zd):\n", object_index); + break; + case KFENCE_ERROR_INVALID: + pr_err("BUG: KFENCE: invalid access in %pS\n\n", (void *)stack_entries[skipnr]); + pr_err("Invalid access at 0x" PTR_FMT ":\n", (void *)address); + break; + case KFENCE_ERROR_INVALID_FREE: + pr_err("BUG: KFENCE: invalid free in %pS\n\n", (void *)stack_entries[skipnr]); + pr_err("Invalid free of 0x" PTR_FMT " (in kfence-#%zd):\n", (void *)address, + object_index); + break; + } + + /* Print stack trace and object info. */ + stack_trace_print(stack_entries + skipnr, num_stack_entries - skipnr, 0); + + if (meta) { + pr_err("\n"); + kfence_print_object(NULL, meta); + } + + /* Print report footer. */ + pr_err("\n"); + dump_stack_print_info(KERN_ERR); + pr_err("==================================================================\n"); + + lockdep_on(); + + if (panic_on_warn) + panic("panic_on_warn set ...\n"); + + /* We encountered a memory unsafety error, taint the kernel! */ + add_taint(TAINT_BAD_PAGE, LOCKDEP_STILL_OK); +} -- 2.25.1

1 0

[PATCH 0/9]
by 1415317271＠qq.com 18 Aug '21

18 Aug '21

From: shang <1415317271(a)qq.com> Transplantation of KFENCE KFENCE could detect many types of memory safety errors. The test cases successfully output the log when booting the kernel after enabling the KFENCE and KFENCE integration test suite at the openEuler OLK 5.10 kernel compile. Yingjie Shang: Transplant KFENCE from Linux kernel v5.13 to openEuler kernel OLK 5.10. Bixuan Cui: Reviewd the transplant patches. Alexander Potapenko (5): mm: add Kernel Electric-Fence infrastructure x86, kfence: enable KFENCE for x86 mm, kfence: insert KFENCE hooks for SLAB mm, kfence: insert KFENCE hooks for SLUB kfence, kasan: make KFENCE compatible with KASAN Marco Elver (4): arm64, kfence: enable KFENCE for ARM64 kfence: use pt_regs to generate stack trace on faults kfence, Documentation: add KFENCE documentation kfence: add test suite Documentation/dev-tools/index.rst | 1 + Documentation/dev-tools/kfence.rst | 298 ++++++++++ arch/arm64/Kconfig | 1 + arch/arm64/include/asm/kfence.h | 22 + arch/arm64/mm/fault.c | 4 + arch/arm64/mm/mmu.c | 7 +- arch/x86/Kconfig | 1 + arch/x86/include/asm/kfence.h | 64 +++ arch/x86/mm/fault.c | 5 + include/linux/kfence.h | 222 ++++++++ include/linux/slab_def.h | 3 + include/linux/slub_def.h | 3 + init/main.c | 3 + lib/Kconfig.debug | 1 + lib/Kconfig.kfence | 82 +++ mm/Makefile | 1 + mm/kasan/common.c | 6 + mm/kasan/generic.c | 3 +- mm/kfence/Makefile | 6 + mm/kfence/core.c | 845 ++++++++++++++++++++++++++++ mm/kfence/kfence.h | 113 ++++ mm/kfence/kfence_test.c | 858 +++++++++++++++++++++++++++++ mm/kfence/report.c | 258 +++++++++ mm/slab.c | 38 +- mm/slab_common.c | 5 +- mm/slub.c | 61 +- 26 files changed, 2884 insertions(+), 27 deletions(-) create mode 100644 Documentation/dev-tools/kfence.rst create mode 100644 arch/arm64/include/asm/kfence.h create mode 100644 arch/x86/include/asm/kfence.h create mode 100644 include/linux/kfence.h create mode 100644 lib/Kconfig.kfence create mode 100644 mm/kfence/Makefile create mode 100644 mm/kfence/core.c create mode 100644 mm/kfence/kfence.h create mode 100644 mm/kfence/kfence_test.c create mode 100644 mm/kfence/report.c -- 2.25.1

1 0

回复：[PATCH kernel-4.19 0/4] Introduce default passthrough mode for some SoCs
by guohui＠uniontech.com 17 Aug '21

17 Aug '21

1 0

【Meeting Notice】openEuler kernel 技术分享第十期 & 双周例会 Time: 2021-08-20 14:00-17:00
by Meeting Book 17 Aug '21

17 Aug '21

1 0

[PATCH kernel-4.19 1/2] hso: fix bailout in error case of probe
by Yang Yingliang 17 Aug '21

17 Aug '21

From: Oliver Neukum <oneukum(a)suse.com> mainline inclusion from mainline-v5.9-rc1 commit 5fcfb6d0bfcda17f0d0656e4e5b3710af2bbaae5 category: bugfix bugzilla: NA CVE: CVE-2021-37159 --------------------------- The driver tries to reuse code for disconnect in case of a failed probe. If resources need to be freed after an error in probe, the netdev must not be freed because it has never been registered. Fix it by telling the helper which path we are in. Signed-off-by: Oliver Neukum <oneukum(a)suse.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/net/usb/hso.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/usb/hso.c b/drivers/net/usb/hso.c index a66077f514572..0839da773e62b 100644 --- a/drivers/net/usb/hso.c +++ b/drivers/net/usb/hso.c @@ -2368,7 +2368,7 @@ static int remove_net_device(struct hso_device *hso_dev) } /* Frees our network device */ -static void hso_free_net_device(struct hso_device *hso_dev) +static void hso_free_net_device(struct hso_device *hso_dev, bool bailout) { int i; struct hso_net *hso_net = dev2net(hso_dev); @@ -2391,7 +2391,7 @@ static void hso_free_net_device(struct hso_device *hso_dev) kfree(hso_net->mux_bulk_tx_buf); hso_net->mux_bulk_tx_buf = NULL; - if (hso_net->net) + if (hso_net->net && !bailout) free_netdev(hso_net->net); kfree(hso_dev); @@ -2567,7 +2567,7 @@ static struct hso_device *hso_create_net_device(struct usb_interface *interface, return hso_dev; exit: - hso_free_net_device(hso_dev); + hso_free_net_device(hso_dev, true); return NULL; } @@ -3132,7 +3132,7 @@ static void hso_free_interface(struct usb_interface *interface) rfkill_unregister(rfk); rfkill_destroy(rfk); } - hso_free_net_device(network_table[i]); + hso_free_net_device(network_table[i], false); } } } -- 2.25.1

1 1

请教IMA完整性度量问题
by Zhoumingxing 17 Aug '21

17 Aug '21

看了天行老师介绍openEuler 内核完整性度量的视频之后，主要有几个问题想请教 1.我们在开启了操作系统的IMA度量之后，系统中例如vim查看一个文件，那么就会相应在度量日志中增加度量记录，这种情况是因为默认的IMA度量策略的特点吗？如果我想更改系统的IMA度量策略，请问应该怎么操作呢？比如我想只度量某个可执行文件，能不能修改策略指定只度量该可执行文件的路径，这样开启IMA度量之后，度量日志里面就只有两条记录，度量日志文件也不因为我vim文件而变化。 2.老师在视频中讲到在OpenEuler上部署IMA时，添加grub启动参数详细的可以查看文档，具体指的是哪个参考文档呢？麻烦老师抽空看一下，超级感谢！

1 0

[PATCH kernel-4.19 0/8] backport linux-4.19.204
by Yang Yingliang 17 Aug '21

17 Aug '21

Daniel Borkmann (1): bpf, selftests: Adjust few selftest outcomes wrt unreachable code Greg Kroah-Hartman (1): Linux 4.19.204 Lai Jiangshan (1): KVM: X86: MMU: Use the correct inherited permissions to get shadow page Masami Hiramatsu (1): tracing: Reject string operand in the histogram expression Miklos Szeredi (1): ovl: prevent private clone if bind mount is not allowed Pali Rohár (1): ppp: Fix generating ppp unit id when ifname is not specified Sean Christopherson (1): KVM: SVM: Fix off-by-one indexing when nullifying last used SEV VMCB YueHaibing (1): net: xilinx_emaclite: Do not print real IOMEM pointer Documentation/virtual/kvm/mmu.txt | 4 +- Makefile | 2 +- arch/x86/kvm/paging_tmpl.h | 14 ++++--- arch/x86/kvm/svm.c | 2 +- drivers/net/ethernet/xilinx/xilinx_emaclite.c | 5 +-- drivers/net/ppp/ppp_generic.c | 19 +++++++-- fs/namespace.c | 42 ++++++++++++------- kernel/trace/trace_events_hist.c | 14 +++++++ tools/testing/selftests/bpf/test_verifier.c | 2 + 9 files changed, 74 insertions(+), 30 deletions(-) -- 2.25.1

1 8

[PATCH kernel-4.19 01/54] Revert "ACPICA: Fix memory leak caused by _CID repair function"
by Yang Yingliang 16 Aug '21

16 Aug '21

From: "Rafael J. Wysocki" <rafael.j.wysocki(a)intel.com> stable inclusion from linux-4.19.203 commit 87db7214e292d6b53e2068311c090acad47ad272 -------------------------------- commit 6511a8b5b7a65037340cd8ee91a377811effbc83 upstream. Revert commit c27bac0314131 ("ACPICA: Fix memory leak caused by _CID repair function") which is reported to cause a boot issue on Acer Swift 3 (SF314-51). Reported-by: Adrien Precigout <dev(a)asdrip.fr> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki(a)intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/acpi/acpica/nsrepair2.c | 7 ------- 1 file changed, 7 deletions(-) diff --git a/drivers/acpi/acpica/nsrepair2.c b/drivers/acpi/acpica/nsrepair2.c index 4c8ce483805d8..a3bd6280882c3 100644 --- a/drivers/acpi/acpica/nsrepair2.c +++ b/drivers/acpi/acpica/nsrepair2.c @@ -375,13 +375,6 @@ acpi_ns_repair_CID(struct acpi_evaluate_info *info, (*element_ptr)->common.reference_count = original_ref_count; - - /* - * The original_element holds a reference from the package object - * that represents _HID. Since a new element was created by _HID, - * remove the reference from the _CID package. - */ - acpi_ut_remove_reference(original_element); } element_ptr++; -- 2.25.1

1 53

[PATCH openEuler-1.0-LTS 1/4] scsi: iscsi: Fix conn use after free during resets
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Mike Christie <michael.christie(a)oracle.com> stable inclusion from linux-4.19.198 commit bf20d85a88384574fabb3d53ad62a8af57e7ab11 -------------------------------- If we haven't done a unbind target call we can race where iscsi_conn_teardown wakes up the EH thread and then frees the conn while those threads are still accessing the conn ehwait. We can only do one TMF per session so this just moves the TMF fields from the conn to the session. We can then rely on the iscsi_session_teardown->iscsi_remove_session->__iscsi_unbind_session call to remove the target and it's devices, and know after that point there is no device or scsi-ml callout trying to access the session. Link: https://lore.kernel.org/r/20210525181821.7617-14-michael.christie@oracle.com Reviewed-by: Lee Duncan <lduncan(a)suse.com> Signed-off-by: Mike Christie <michael.christie(a)oracle.com> Signed-off-by: Martin K. Petersen <martin.petersen(a)oracle.com> conflcits: drivers/scsi/libiscsi.c Signed-off-by: Ye Bin <yebin10(a)huawei.com> Reviewed-by: Jason Yan <yanaijie(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/scsi/libiscsi.c | 116 +++++++++++++++++++--------------------- include/scsi/libiscsi.h | 11 ++-- 2 files changed, 61 insertions(+), 66 deletions(-) diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c index 8ea441fe8aba3..75096f1565425 100644 --- a/drivers/scsi/libiscsi.c +++ b/drivers/scsi/libiscsi.c @@ -265,11 +265,11 @@ static int iscsi_prep_bidi_ahs(struct iscsi_task *task) */ static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode) { - struct iscsi_conn *conn = task->conn; - struct iscsi_tm *tmf = &conn->tmhdr; + struct iscsi_session *session = task->conn->session; + struct iscsi_tm *tmf = &session->tmhdr; u64 hdr_lun; - if (conn->tmf_state == TMF_INITIAL) + if (session->tmf_state == TMF_INITIAL) return 0; if ((tmf->opcode & ISCSI_OPCODE_MASK) != ISCSI_OP_SCSI_TMFUNC) @@ -289,24 +289,19 @@ static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode) * Fail all SCSI cmd PDUs */ if (opcode != ISCSI_OP_SCSI_DATA_OUT) { - iscsi_conn_printk(KERN_INFO, conn, - "task [op %x itt " - "0x%x/0x%x] " - "rejected.\n", - opcode, task->itt, - task->hdr_itt); + iscsi_session_printk(KERN_INFO, session, + "task [op %x itt 0x%x/0x%x] rejected.\n", + opcode, task->itt, task->hdr_itt); return -EACCES; } /* * And also all data-out PDUs in response to R2T * if fast_abort is set. */ - if (conn->session->fast_abort) { - iscsi_conn_printk(KERN_INFO, conn, - "task [op %x itt " - "0x%x/0x%x] fast abort.\n", - opcode, task->itt, - task->hdr_itt); + if (session->fast_abort) { + iscsi_session_printk(KERN_INFO, session, + "task [op %x itt 0x%x/0x%x] fast abort.\n", + opcode, task->itt, task->hdr_itt); return -EACCES; } break; @@ -319,7 +314,7 @@ static int iscsi_check_tmf_restrictions(struct iscsi_task *task, int opcode) */ if (opcode == ISCSI_OP_SCSI_DATA_OUT && task->hdr_itt == tmf->rtt) { - ISCSI_DBG_SESSION(conn->session, + ISCSI_DBG_SESSION(session, "Preventing task %x/%x from sending " "data-out due to abort task in " "progress\n", task->itt, @@ -993,20 +988,21 @@ iscsi_data_in_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr, static void iscsi_tmf_rsp(struct iscsi_conn *conn, struct iscsi_hdr *hdr) { struct iscsi_tm_rsp *tmf = (struct iscsi_tm_rsp *)hdr; + struct iscsi_session *session = conn->session; conn->exp_statsn = be32_to_cpu(hdr->statsn) + 1; conn->tmfrsp_pdus_cnt++; - if (conn->tmf_state != TMF_QUEUED) + if (session->tmf_state != TMF_QUEUED) return; if (tmf->response == ISCSI_TMF_RSP_COMPLETE) - conn->tmf_state = TMF_SUCCESS; + session->tmf_state = TMF_SUCCESS; else if (tmf->response == ISCSI_TMF_RSP_NO_TASK) - conn->tmf_state = TMF_NOT_FOUND; + session->tmf_state = TMF_NOT_FOUND; else - conn->tmf_state = TMF_FAILED; - wake_up(&conn->ehwait); + session->tmf_state = TMF_FAILED; + wake_up(&session->ehwait); } static int iscsi_send_nopout(struct iscsi_conn *conn, struct iscsi_nopin *rhdr) @@ -1879,15 +1875,14 @@ EXPORT_SYMBOL_GPL(iscsi_target_alloc); static void iscsi_tmf_timedout(struct timer_list *t) { - struct iscsi_conn *conn = from_timer(conn, t, tmf_timer); - struct iscsi_session *session = conn->session; + struct iscsi_session *session = from_timer(session, t, tmf_timer); spin_lock(&session->frwd_lock); - if (conn->tmf_state == TMF_QUEUED) { - conn->tmf_state = TMF_TIMEDOUT; + if (session->tmf_state == TMF_QUEUED) { + session->tmf_state = TMF_TIMEDOUT; ISCSI_DBG_EH(session, "tmf timedout\n"); /* unblock eh_abort() */ - wake_up(&conn->ehwait); + wake_up(&session->ehwait); } spin_unlock(&session->frwd_lock); } @@ -1910,8 +1905,8 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn, return -EPERM; } conn->tmfcmd_pdus_cnt++; - conn->tmf_timer.expires = timeout * HZ + jiffies; - add_timer(&conn->tmf_timer); + session->tmf_timer.expires = timeout * HZ + jiffies; + add_timer(&session->tmf_timer); ISCSI_DBG_EH(session, "tmf set timeout\n"); spin_unlock_bh(&session->frwd_lock); @@ -1925,12 +1920,12 @@ static int iscsi_exec_task_mgmt_fn(struct iscsi_conn *conn, * 3) session is terminated or restarted or userspace has * given up on recovery */ - wait_event_interruptible(conn->ehwait, age != session->age || + wait_event_interruptible(session->ehwait, age != session->age || session->state != ISCSI_STATE_LOGGED_IN || - conn->tmf_state != TMF_QUEUED); + session->tmf_state != TMF_QUEUED); if (signal_pending(current)) flush_signals(current); - del_timer_sync(&conn->tmf_timer); + del_timer_sync(&session->tmf_timer); mutex_lock(&session->eh_mutex); spin_lock_bh(&session->frwd_lock); @@ -2320,17 +2315,17 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) } /* only have one tmf outstanding at a time */ - if (conn->tmf_state != TMF_INITIAL) + if (session->tmf_state != TMF_INITIAL) goto failed; - conn->tmf_state = TMF_QUEUED; + session->tmf_state = TMF_QUEUED; - hdr = &conn->tmhdr; + hdr = &session->tmhdr; iscsi_prep_abort_task_pdu(task, hdr); if (iscsi_exec_task_mgmt_fn(conn, hdr, age, session->abort_timeout)) goto failed; - switch (conn->tmf_state) { + switch (session->tmf_state) { case TMF_SUCCESS: spin_unlock_bh(&session->frwd_lock); /* @@ -2345,7 +2340,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) */ spin_lock_bh(&session->frwd_lock); fail_scsi_task(task, DID_ABORT); - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; memset(hdr, 0, sizeof(*hdr)); spin_unlock_bh(&session->frwd_lock); iscsi_start_tx(conn); @@ -2356,7 +2351,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) goto failed_unlocked; case TMF_NOT_FOUND: if (!sc->SCp.ptr) { - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; memset(hdr, 0, sizeof(*hdr)); /* task completed before tmf abort response */ ISCSI_DBG_EH(session, "sc completed while abort in " @@ -2365,7 +2360,7 @@ int iscsi_eh_abort(struct scsi_cmnd *sc) } /* fall through */ default: - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; goto failed; } @@ -2424,11 +2419,11 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc) conn = session->leadconn; /* only have one tmf outstanding at a time */ - if (conn->tmf_state != TMF_INITIAL) + if (session->tmf_state != TMF_INITIAL) goto unlock; - conn->tmf_state = TMF_QUEUED; + session->tmf_state = TMF_QUEUED; - hdr = &conn->tmhdr; + hdr = &session->tmhdr; iscsi_prep_lun_reset_pdu(sc, hdr); if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age, @@ -2437,7 +2432,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc) goto unlock; } - switch (conn->tmf_state) { + switch (session->tmf_state) { case TMF_SUCCESS: break; case TMF_TIMEDOUT: @@ -2445,7 +2440,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc) iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST); goto done; default: - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; goto unlock; } @@ -2457,7 +2452,7 @@ int iscsi_eh_device_reset(struct scsi_cmnd *sc) spin_lock_bh(&session->frwd_lock); memset(hdr, 0, sizeof(*hdr)); fail_scsi_tasks(conn, sc->device->lun, DID_ERROR); - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; spin_unlock_bh(&session->frwd_lock); iscsi_start_tx(conn); @@ -2480,8 +2475,7 @@ void iscsi_session_recovery_timedout(struct iscsi_cls_session *cls_session) spin_lock_bh(&session->frwd_lock); if (session->state != ISCSI_STATE_LOGGED_IN) { session->state = ISCSI_STATE_RECOVERY_FAILED; - if (session->leadconn) - wake_up(&session->leadconn->ehwait); + wake_up(&session->ehwait); } spin_unlock_bh(&session->frwd_lock); } @@ -2536,7 +2530,7 @@ int iscsi_eh_session_reset(struct scsi_cmnd *sc) iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST); ISCSI_DBG_EH(session, "wait for relogin\n"); - wait_event_interruptible_timeout(conn->ehwait, + wait_event_interruptible_timeout(session->ehwait, session->state == ISCSI_STATE_TERMINATE || session->state == ISCSI_STATE_LOGGED_IN || session->state == ISCSI_STATE_RECOVERY_FAILED, @@ -2598,11 +2592,11 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc) conn = session->leadconn; /* only have one tmf outstanding at a time */ - if (conn->tmf_state != TMF_INITIAL) + if (session->tmf_state != TMF_INITIAL) goto unlock; - conn->tmf_state = TMF_QUEUED; + session->tmf_state = TMF_QUEUED; - hdr = &conn->tmhdr; + hdr = &session->tmhdr; iscsi_prep_tgt_reset_pdu(sc, hdr); if (iscsi_exec_task_mgmt_fn(conn, hdr, session->age, @@ -2611,7 +2605,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc) goto unlock; } - switch (conn->tmf_state) { + switch (session->tmf_state) { case TMF_SUCCESS: break; case TMF_TIMEDOUT: @@ -2619,7 +2613,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc) iscsi_conn_failure(conn, ISCSI_ERR_SCSI_EH_SESSION_RST); goto done; default: - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; goto unlock; } @@ -2631,7 +2625,7 @@ static int iscsi_eh_target_reset(struct scsi_cmnd *sc) spin_lock_bh(&session->frwd_lock); memset(hdr, 0, sizeof(*hdr)); fail_scsi_tasks(conn, -1, DID_ERROR); - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; spin_unlock_bh(&session->frwd_lock); iscsi_start_tx(conn); @@ -2961,7 +2955,10 @@ iscsi_session_setup(struct iscsi_transport *iscsit, struct Scsi_Host *shost, session->tt = iscsit; session->dd_data = cls_session->dd_data + sizeof(*session); + session->tmf_state = TMF_INITIAL; + timer_setup(&session->tmf_timer, iscsi_tmf_timedout, 0); mutex_init(&session->eh_mutex); + spin_lock_init(&session->frwd_lock); spin_lock_init(&session->back_lock); @@ -3065,7 +3062,7 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size, conn->c_stage = ISCSI_CONN_INITIAL_STAGE; conn->id = conn_idx; conn->exp_statsn = 0; - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; conn->intimate_cpu = -1; timer_setup(&conn->transport_timer, iscsi_check_transport_timeouts, 0); @@ -3091,8 +3088,7 @@ iscsi_conn_setup(struct iscsi_cls_session *cls_session, int dd_size, goto login_task_data_alloc_fail; conn->login_task->data = conn->data = data; - timer_setup(&conn->tmf_timer, iscsi_tmf_timedout, 0); - init_waitqueue_head(&conn->ehwait); + init_waitqueue_head(&session->ehwait); return cls_conn; @@ -3127,7 +3123,7 @@ void iscsi_conn_teardown(struct iscsi_cls_conn *cls_conn) * leading connection? then give up on recovery. */ session->state = ISCSI_STATE_TERMINATE; - wake_up(&conn->ehwait); + wake_up(&session->ehwait); } spin_unlock_bh(&session->frwd_lock); @@ -3202,7 +3198,7 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn) * commands after successful recovery */ conn->stop_stage = 0; - conn->tmf_state = TMF_INITIAL; + session->tmf_state = TMF_INITIAL; session->age++; if (session->age == 16) session->age = 0; @@ -3216,7 +3212,7 @@ int iscsi_conn_start(struct iscsi_cls_conn *cls_conn) spin_unlock_bh(&session->frwd_lock); iscsi_unblock_session(session->cls_session); - wake_up(&conn->ehwait); + wake_up(&session->ehwait); return 0; } EXPORT_SYMBOL_GPL(iscsi_conn_start); @@ -3309,7 +3305,7 @@ static void iscsi_start_session_recovery(struct iscsi_session *session, spin_lock_bh(&session->frwd_lock); fail_scsi_tasks(conn, -1, DID_TRANSPORT_DISRUPTED); fail_mgmt_tasks(session, conn); - memset(&conn->tmhdr, 0, sizeof(conn->tmhdr)); + memset(&session->tmhdr, 0, sizeof(session->tmhdr)); spin_unlock_bh(&session->frwd_lock); mutex_unlock(&session->eh_mutex); } diff --git a/include/scsi/libiscsi.h b/include/scsi/libiscsi.h index c14d739c88873..156232a9e48b2 100644 --- a/include/scsi/libiscsi.h +++ b/include/scsi/libiscsi.h @@ -208,12 +208,6 @@ struct iscsi_conn { unsigned long suspend_tx; /* suspend Tx */ unsigned long suspend_rx; /* suspend Rx */ - /* abort */ - wait_queue_head_t ehwait; /* used in eh_abort() */ - struct iscsi_tm tmhdr; - struct timer_list tmf_timer; - int tmf_state; /* see TMF_INITIAL, etc.*/ - /* negotiated params */ unsigned max_recv_dlength; /* initiator_max_recv_dsl*/ unsigned max_xmit_dlength; /* target_max_recv_dsl */ @@ -284,6 +278,11 @@ struct iscsi_session { * and recv lock. */ struct mutex eh_mutex; + /* abort */ + wait_queue_head_t ehwait; /* used in eh_abort() */ + struct iscsi_tm tmhdr; + struct timer_list tmf_timer; + int tmf_state; /* see TMF_INITIAL, etc.*/ /* iSCSI session-wide sequencing */ uint32_t cmdsn; -- 2.25.1

1 3

[PATCH openEuler-21.09] once: Fix panic when module unload
by Zheng Zengkai 16 Aug '21

16 Aug '21

From: Kefeng Wang <wangkefeng.wang(a)huawei.com> mainline inclusion from mainline-5.14-rc6 commit 1027b96ec9d34f9abab69bc1a4dc5b1ad8ab1349 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I45V8P CVE: NA ------------------------------------------------- DO_ONCE DEFINE_STATIC_KEY_TRUE(___once_key); __do_once_done once_disable_jump(once_key); INIT_WORK(&w->work, once_deferred); struct once_work *w; w->key = key; schedule_work(&w->work); module unload //*the key is destroy* process_one_work once_deferred BUG_ON(!static_key_enabled(work->key)); static_key_count((struct static_key *)x) //*access key, crash* When module uses DO_ONCE mechanism, it could crash due to the above concurrency problem, we could reproduce it with link[1]. Fix it by add/put module refcount in the once work process. [1] https://lore.kernel.org/netdev/eaa6c371-465e-57eb-6be9-f4b16b9d7cbf@huawei.… Cc: Hannes Frederic Sowa <hannes(a)stressinduktion.org> Cc: Daniel Borkmann <daniel(a)iogearbox.net> Cc: David S. Miller <davem(a)davemloft.net> Cc: Eric Dumazet <edumazet(a)google.com> Reported-by: Minmin chen <chenmingmin(a)huawei.com> Signed-off-by: Kefeng Wang <wangkefeng.wang(a)huawei.com> Acked-by: Hannes Frederic Sowa <hannes(a)stressinduktion.org> Signed-off-by: David S. Miller <davem(a)davemloft.net> (cherry picked from commit 1027b96ec9d34f9abab69bc1a4dc5b1ad8ab1349) Signed-off-by: Kefeng Wang <wangkefeng.wang(a)huawei.com> Reviewed-by: Xie XiuQi <xiexiuqi(a)huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai(a)huawei.com> --- include/linux/once.h | 4 ++-- lib/once.c | 11 ++++++++--- 2 files changed, 10 insertions(+), 5 deletions(-) diff --git a/include/linux/once.h b/include/linux/once.h index 9225ee6d96c7..ae6f4eb41cbe 100644 --- a/include/linux/once.h +++ b/include/linux/once.h @@ -7,7 +7,7 @@ bool __do_once_start(bool *done, unsigned long *flags); void __do_once_done(bool *done, struct static_key_true *once_key, - unsigned long *flags); + unsigned long *flags, struct module *mod); /* Call a function exactly once. The idea of DO_ONCE() is to perform * a function call such as initialization of random seeds, etc, only @@ -46,7 +46,7 @@ void __do_once_done(bool *done, struct static_key_true *once_key, if (unlikely(___ret)) { \ func(__VA_ARGS__); \ __do_once_done(&___done, &___once_key, \ - &___flags); \ + &___flags, THIS_MODULE); \ } \ } \ ___ret; \ diff --git a/lib/once.c b/lib/once.c index 8b7d6235217e..59149bf3bfb4 100644 --- a/lib/once.c +++ b/lib/once.c @@ -3,10 +3,12 @@ #include <linux/spinlock.h> #include <linux/once.h> #include <linux/random.h> +#include <linux/module.h> struct once_work { struct work_struct work; struct static_key_true *key; + struct module *module; }; static void once_deferred(struct work_struct *w) @@ -16,10 +18,11 @@ static void once_deferred(struct work_struct *w) work = container_of(w, struct once_work, work); BUG_ON(!static_key_enabled(work->key)); static_branch_disable(work->key); + module_put(work->module); kfree(work); } -static void once_disable_jump(struct static_key_true *key) +static void once_disable_jump(struct static_key_true *key, struct module *mod) { struct once_work *w; @@ -29,6 +32,8 @@ static void once_disable_jump(struct static_key_true *key) INIT_WORK(&w->work, once_deferred); w->key = key; + w->module = mod; + __module_get(mod); schedule_work(&w->work); } @@ -53,11 +58,11 @@ bool __do_once_start(bool *done, unsigned long *flags) EXPORT_SYMBOL(__do_once_start); void __do_once_done(bool *done, struct static_key_true *once_key, - unsigned long *flags) + unsigned long *flags, struct module *mod) __releases(once_lock) { *done = true; spin_unlock_irqrestore(&once_lock, *flags); - once_disable_jump(once_key); + once_disable_jump(once_key, mod); } EXPORT_SYMBOL(__do_once_done); -- 2.20.1

1 0

[PATCH openEuler-1.0-LTS] scsi: sr: Return correct event when media event code is 3
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Li Manyi <limanyi(a)uniontech.com> stable inclusion from linux-4.19.203 commit 489492b5a81f0f6de1ffa246e4183e479298fd2b -------------------------------- [ Upstream commit 5c04243a56a7977185b00400e59ca7e108004faf ] Media event code 3 is defined in the MMC-6 spec as follows: "MediaRemoval: The media has been removed from the specified slot, and the Drive is unable to access the media without user intervention. This applies to media changers only." This indicated that treating the condition as an EJECT_REQUEST was appropriate. However, doing so had the unfortunate side-effect of causing the drive tray to be physically ejected on resume. Instead treat the event as a MEDIA_CHANGE request. Fixes: 7dd753ca59d6 ("scsi: sr: Return appropriate error code when disk is ejected") Link: https://bugzilla.kernel.org/show_bug.cgi?id=213759 Link: https://lore.kernel.org/r/20210726114913.6760-1-limanyi@uniontech.com Signed-off-by: Li Manyi <limanyi(a)uniontech.com> Signed-off-by: Martin K. Petersen <martin.petersen(a)oracle.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Reviewed-by: Jason Yan <yanaijie(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/scsi/sr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c index acf0c244141f4..84dd776d36c33 100644 --- a/drivers/scsi/sr.c +++ b/drivers/scsi/sr.c @@ -217,7 +217,7 @@ static unsigned int sr_get_events(struct scsi_device *sdev) else if (med->media_event_code == 2) return DISK_EVENT_MEDIA_CHANGE; else if (med->media_event_code == 3) - return DISK_EVENT_EJECT_REQUEST; + return DISK_EVENT_MEDIA_CHANGE; return 0; } -- 2.25.1

1 0

[PATCH openEuler-1.0-LTS 1/2] sctp: move the active_key update after sh_keys is added
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Xin Long <lucien.xin(a)gmail.com> stable inclusion from linux-4.19.203 commit f91e7bd934c705f25dc6651e29e9c857d48a51f4 -------------------------------- [ Upstream commit ae954bbc451d267f7d60d7b49db811d5a68ebd7b ] In commit 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced"), sctp_auth_asoc_init_active_key() is called to update the active_key right after the old key is deleted and before the new key is added, and it caused that the active_key could be found with the key_id. In Ying Xu's testing, the BUG_ON in sctp_auth_asoc_init_active_key() was triggered: [ ] kernel BUG at net/sctp/auth.c:416! [ ] RIP: 0010:sctp_auth_asoc_init_active_key.part.8+0xe7/0xf0 [sctp] [ ] Call Trace: [ ] sctp_auth_set_key+0x16d/0x1b0 [sctp] [ ] sctp_setsockopt.part.33+0x1ba9/0x2bd0 [sctp] [ ] __sys_setsockopt+0xd6/0x1d0 [ ] __x64_sys_setsockopt+0x20/0x30 [ ] do_syscall_64+0x5b/0x1a0 So fix it by moving the active_key update after sh_keys is added. Fixes: 58acd1009226 ("sctp: update active_key for asoc when old key is being replaced") Reported-by: Ying Xu <yinxu(a)redhat.com> Signed-off-by: Xin Long <lucien.xin(a)gmail.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- net/sctp/auth.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/net/sctp/auth.c b/net/sctp/auth.c index b2ca66c4a21d2..9e0c98df20daf 100644 --- a/net/sctp/auth.c +++ b/net/sctp/auth.c @@ -880,14 +880,18 @@ int sctp_auth_set_key(struct sctp_endpoint *ep, memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength); cur_key->key = key; - if (replace) { - list_del_init(&shkey->key_list); - sctp_auth_shkey_release(shkey); - if (asoc && asoc->active_key_id == auth_key->sca_keynumber) - sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); + if (!replace) { + list_add(&cur_key->key_list, sh_keys); + return 0; } + + list_del_init(&shkey->key_list); + sctp_auth_shkey_release(shkey); list_add(&cur_key->key_list, sh_keys); + if (asoc && asoc->active_key_id == auth_key->sca_keynumber) + sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); + return 0; } -- 2.25.1

1 1

[PATCH 0/9] Transplantation of KFENCE
by Xie XiuQi 16 Aug '21

16 Aug '21

Hi shang, Thanks for your patchset. Please subscribe the kernel(a)openeuler.org mailing list first, and then resend this patchset again, or your patchset would be blocked. Others who in the mailing list could not receive the emails. Click this link for subscribe mailing list: https://openeuler.org/zh/community/mailing-list/ --- Xie XiuQi On 2021/8/16 20:27, kernel-owner(a)openeuler.org wrote: > As list administrator, your authorization is requested for the > following mailing list posting: > > List: kernel(a)openeuler.org > From: 1415317271(a)qq.com > Subject: [PATCH 0/9] > > The message is being held because: > > The message is not from a list member > > At your convenience, visit your dashboard to approve or deny the > request. >

1 0

[PATCH openEuler-1.0-LTS] usb: max-3421: Prevent corruption of freed memory
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Mark Tomlinson <mark.tomlinson(a)alliedtelesis.co.nz> stable inclusion from linux-4.19.199 commit 51fc12f4d37622fa0c481604833f98f11b1cac4f CVE: CVE-2021-38204 -------------------------------- commit b5fdf5c6e6bee35837e160c00ac89327bdad031b upstream. The MAX-3421 USB driver remembers the state of the USB toggles for a device/endpoint. To save SPI writes, this was only done when a new device/endpoint was being used. Unfortunately, if the old device was removed, this would cause writes to freed memory. To fix this, a simpler scheme is used. The toggles are read from hardware when a URB is completed, and the toggles are always written to hardware when any URB transaction is started. This will cause a few more SPI transactions, but no causes kernel panics. Fixes: 2d53139f3162 ("Add support for using a MAX3421E chip as a host driver.") Cc: stable <stable(a)vger.kernel.org> Signed-off-by: Mark Tomlinson <mark.tomlinson(a)alliedtelesis.co.nz> Link: https://lore.kernel.org/r/20210625031456.8632-1-mark.tomlinson@alliedtelesi… Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/usb/host/max3421-hcd.c | 44 +++++++++++----------------------- 1 file changed, 14 insertions(+), 30 deletions(-) diff --git a/drivers/usb/host/max3421-hcd.c b/drivers/usb/host/max3421-hcd.c index afa321ab55fcf..4a33a18dc0b31 100644 --- a/drivers/usb/host/max3421-hcd.c +++ b/drivers/usb/host/max3421-hcd.c @@ -153,8 +153,6 @@ struct max3421_hcd { */ struct urb *curr_urb; enum scheduling_pass sched_pass; - struct usb_device *loaded_dev; /* dev that's loaded into the chip */ - int loaded_epnum; /* epnum whose toggles are loaded */ int urb_done; /* > 0 -> no errors, < 0: errno */ size_t curr_len; u8 hien; @@ -492,39 +490,17 @@ max3421_set_speed(struct usb_hcd *hcd, struct usb_device *dev) * Caller must NOT hold HCD spinlock. */ static void -max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum, - int force_toggles) +max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum) { - struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); - int old_epnum, same_ep, rcvtog, sndtog; - struct usb_device *old_dev; + int rcvtog, sndtog; u8 hctl; - old_dev = max3421_hcd->loaded_dev; - old_epnum = max3421_hcd->loaded_epnum; - - same_ep = (dev == old_dev && epnum == old_epnum); - if (same_ep && !force_toggles) - return; - - if (old_dev && !same_ep) { - /* save the old end-points toggles: */ - u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); - - rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1; - sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; - - /* no locking: HCD (i.e., we) own toggles, don't we? */ - usb_settoggle(old_dev, old_epnum, 0, rcvtog); - usb_settoggle(old_dev, old_epnum, 1, sndtog); - } /* setup new endpoint's toggle bits: */ rcvtog = usb_gettoggle(dev, epnum, 0); sndtog = usb_gettoggle(dev, epnum, 1); hctl = (BIT(rcvtog + MAX3421_HCTL_RCVTOG0_BIT) | BIT(sndtog + MAX3421_HCTL_SNDTOG0_BIT)); - max3421_hcd->loaded_epnum = epnum; spi_wr8(hcd, MAX3421_REG_HCTL, hctl); /* @@ -532,7 +508,6 @@ max3421_set_address(struct usb_hcd *hcd, struct usb_device *dev, int epnum, * address-assignment so it's best to just always load the * address whenever the end-point changed/was forced. */ - max3421_hcd->loaded_dev = dev; spi_wr8(hcd, MAX3421_REG_PERADDR, dev->devnum); } @@ -667,7 +642,7 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) struct max3421_hcd *max3421_hcd = hcd_to_max3421(hcd); struct urb *urb, *curr_urb = NULL; struct max3421_ep *max3421_ep; - int epnum, force_toggles = 0; + int epnum; struct usb_host_endpoint *ep; struct list_head *pos; unsigned long flags; @@ -777,7 +752,6 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) usb_settoggle(urb->dev, epnum, 0, 1); usb_settoggle(urb->dev, epnum, 1, 1); max3421_ep->pkt_state = PKT_STATE_SETUP; - force_toggles = 1; } else max3421_ep->pkt_state = PKT_STATE_TRANSFER; } @@ -785,7 +759,7 @@ max3421_select_and_start_urb(struct usb_hcd *hcd) spin_unlock_irqrestore(&max3421_hcd->lock, flags); max3421_ep->last_active = max3421_hcd->frame_number; - max3421_set_address(hcd, urb->dev, epnum, force_toggles); + max3421_set_address(hcd, urb->dev, epnum); max3421_set_speed(hcd, urb->dev); max3421_next_transfer(hcd, 0); return 1; @@ -1380,6 +1354,16 @@ max3421_urb_done(struct usb_hcd *hcd) status = 0; urb = max3421_hcd->curr_urb; if (urb) { + /* save the old end-points toggles: */ + u8 hrsl = spi_rd8(hcd, MAX3421_REG_HRSL); + int rcvtog = (hrsl >> MAX3421_HRSL_RCVTOGRD_BIT) & 1; + int sndtog = (hrsl >> MAX3421_HRSL_SNDTOGRD_BIT) & 1; + int epnum = usb_endpoint_num(&urb->ep->desc); + + /* no locking: HCD (i.e., we) own toggles, don't we? */ + usb_settoggle(urb->dev, epnum, 0, rcvtog); + usb_settoggle(urb->dev, epnum, 1, sndtog); + max3421_hcd->curr_urb = NULL; spin_lock_irqsave(&max3421_hcd->lock, flags); usb_hcd_unlink_urb_from_ep(hcd, urb); -- 2.25.1

1 0

[PATCH kernel-4.19] net: ll_temac: Fix bug causing buffer descriptor overrun
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Esben Haabendal <esben(a)geanix.com> mainline inclusion from mainline-v5.2-rc1 commit 2c9938e738a273ba315679781a9990c7d3b1831b category: bugfix bugzilla: NA CVE: CVE-2021-38207 --------------------------- As we are actually using a BD for both the skb and each frag contained in it, the oldest TX BD would be overwritten when there was exactly one BD less than needed. Signed-off-by: Esben Haabendal <esben(a)geanix.com> Signed-off-by: David S. Miller <davem(a)davemloft.net> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Reviewed-by: Xiu Jianfeng <xiujianfeng(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/net/ethernet/xilinx/ll_temac_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c index 939de185bc6b8..2caff1a5585e7 100644 --- a/drivers/net/ethernet/xilinx/ll_temac_main.c +++ b/drivers/net/ethernet/xilinx/ll_temac_main.c @@ -689,7 +689,7 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev) start_p = lp->tx_bd_p + sizeof(*lp->tx_bd_v) * lp->tx_bd_tail; cur_p = &lp->tx_bd_v[lp->tx_bd_tail]; - if (temac_check_tx_bd_space(lp, num_frag)) { + if (temac_check_tx_bd_space(lp, num_frag + 1)) { if (!netif_queue_stopped(ndev)) netif_stop_queue(ndev); return NETDEV_TX_BUSY; -- 2.25.1

1 0

[PATCH kernel-4.19] tcp_comp: Avoiding the null pointer problem of ctx in comp_stream_read
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Wang Yufen <wangyufen(a)huawei.com> hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I45UYC?from=project-issue CVE: NA ------------------------------------------------- In comp_stream_read ctx might be null, add null check to avoid oops. And delete unnecessary tcp_comp_err_abort. Signed-off-by: Wang Yufen <wangyufen(a)huawei.com> Reviewed-by: Yue Haibing <yuehaibing(a)huawei.com> Reviewed-by: Wei Yongjun <weiyongjun1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- net/ipv4/tcp_comp.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/ipv4/tcp_comp.c b/net/ipv4/tcp_comp.c index e7f6094b5aeec..f6ebe52f3f7f7 100644 --- a/net/ipv4/tcp_comp.c +++ b/net/ipv4/tcp_comp.c @@ -723,8 +723,6 @@ static int tcp_comp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, if (!ctx->rx.decompressed) { err = tcp_comp_decompress(sk, skb); if (err < 0) { - if (err != -ENOSPC) - tcp_comp_err_abort(sk, EBADMSG); goto recv_end; } ctx->rx.decompressed = true; @@ -758,6 +756,9 @@ bool comp_stream_read(const struct sock *sk) { struct tcp_comp_context *ctx = comp_get_ctx(sk); + if (!ctx) + return false; + if (ctx->rx.pkt) return true; -- 2.25.1

1 0

[PATCH kernel-4.19 1/2] ext4: fix potential uninitialized access to retval in kmmpd
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Ye Bin <yebin10(a)huawei.com> mainline inclusion from mainline-5.14-rc5 commit b66541422824cf6cf20e9a35112e9cb5d82cdf62 category: bugfix bugzilla: 175849 CVE: NA ------------------------------------------------- if (!ext4_has_feature_mmp(sb)) then retval can be unitialized before we jump to the wait_to_exit label. Fixes: 61bb4a1c417e ("ext4: fix possible UAF when remounting r/o a mmp-protected file system") Signed-off-by: Ye Bin <yebin10(a)huawei.com> Link: https://lore.kernel.org/r/20210713022728.2533770-1-yebin10@huawei.com Signed-off-by: Theodore Ts'o <tytso(a)mit.edu> Signed-off-by: Baokun Li <libaokun1(a)huawei.com> Reviewed-by: Zhang Yi <yi.zhang(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- fs/ext4/mmp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/ext4/mmp.c b/fs/ext4/mmp.c index 5af24925ffa83..0e9569dc02da2 100644 --- a/fs/ext4/mmp.c +++ b/fs/ext4/mmp.c @@ -138,7 +138,7 @@ static int kmmpd(void *data) unsigned mmp_check_interval; unsigned long last_update_time; unsigned long diff; - int retval; + int retval = 0; mmp_block = le64_to_cpu(es->s_mmp_block); mmp = (struct mmp_struct *)(bh->b_data); -- 2.25.1

1 1

[PATCH openEuler-1.0-LTS 1/2] blk-mq: fix hang caused by freeze/unfreeze sequence
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Bob Liu <bob.liu(a)oracle.com> mainline inclusion from mainline-v5.2-rc2 commit 7996a8b5511a72465b0b286763c2d8f412b8874a category: bugfix bugzilla: 173119 CVE: NA ----------------------------------------------- The following is a description of a hang in blk_mq_freeze_queue_wait(). The hang happens on attempt to freeze a queue while another task does queue unfreeze. The root cause is an incorrect sequence of percpu_ref_resurrect() and percpu_ref_kill() and as a result those two can be swapped: CPU#0 CPU#1 ---------------- ----------------- q1 = blk_mq_init_queue(shared_tags) q2 = blk_mq_init_queue(shared_tags): blk_mq_add_queue_tag_set(shared_tags): blk_mq_update_tag_set_depth(shared_tags): list_for_each_entry() blk_mq_freeze_queue(q1) > percpu_ref_kill() > blk_mq_freeze_queue_wait() blk_cleanup_queue(q1) blk_mq_freeze_queue(q1) > percpu_ref_kill() ^^^^^^ freeze_depth can't guarantee the order blk_mq_unfreeze_queue() > percpu_ref_resurrect() > blk_mq_freeze_queue_wait() ^^^^^^ Hang here!!!! This wrong sequence raises kernel warning: percpu_ref_kill_and_confirm called more than once on blk_queue_usage_counter_release! WARNING: CPU: 0 PID: 11854 at lib/percpu-refcount.c:336 percpu_ref_kill_and_confirm+0x99/0xb0 But the most unpleasant effect is a hang of a blk_mq_freeze_queue_wait(), which waits for a zero of a q_usage_counter, which never happens because percpu-ref was reinited (instead of being killed) and stays in PERCPU state forever. How to reproduce: - "insmod null_blk.ko shared_tags=1 nr_devices=0 queue_mode=2" - cpu0: python Script.py 0; taskset the corresponding process running on cpu0 - cpu1: python Script.py 1; taskset the corresponding process running on cpu1 Script.py: ------ #!/usr/bin/python3 import os import sys while True: on = "echo 1 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] off = "echo 0 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] os.system(on) os.system(off) ------ This bug was first reported and fixed by Roman, previous discussion: [1] Message id: 1443287365-4244-7-git-send-email-akinobu.mita(a)gmail.com [2] Message id: 1443563240-29306-6-git-send-email-tj(a)kernel.org [3] https://patchwork.kernel.org/patch/9268199/ Reviewed-by: Hannes Reinecke <hare(a)suse.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Reviewed-by: Bart Van Assche <bvanassche(a)acm.org> Reviewed-by: Christoph Hellwig <hch(a)lst.de> Signed-off-by: Roman Pen <roman.penyaev(a)profitbricks.com> Signed-off-by: Bob Liu <bob.liu(a)oracle.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- block/blk-core.c | 3 ++- block/blk-mq.c | 19 ++++++++++--------- include/linux/blkdev.h | 7 ++++++- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 2f66d43c476f3..b67cb175b9737 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -955,7 +955,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) smp_rmb(); wait_event(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && + (!q->mq_freeze_depth && (pm || !blk_queue_pm_only(q))) || blk_queue_dying(q)); if (blk_queue_dying(q)) @@ -1071,6 +1071,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id, queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q); init_waitqueue_head(&q->mq_freeze_wq); + mutex_init(&q->mq_freeze_lock); /* * Init percpu_ref in atomic mode so that it's faster to shutdown. diff --git a/block/blk-mq.c b/block/blk-mq.c index 607ee5dafa2e9..0de720aa544fa 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -136,13 +136,14 @@ void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, void blk_freeze_queue_start(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_inc_return(&q->mq_freeze_depth); - if (freeze_depth == 1) { + mutex_lock(&q->mq_freeze_lock); + if (++q->mq_freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); if (q->mq_ops) blk_mq_run_hw_queues(q, false); + } else { + mutex_unlock(&q->mq_freeze_lock); } } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -193,14 +194,14 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); void blk_mq_unfreeze_queue(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_dec_return(&q->mq_freeze_depth); - WARN_ON_ONCE(freeze_depth < 0); - if (!freeze_depth) { + mutex_lock(&q->mq_freeze_lock); + q->mq_freeze_depth--; + WARN_ON_ONCE(q->mq_freeze_depth < 0); + if (!q->mq_freeze_depth) { percpu_ref_reinit(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } + mutex_unlock(&q->mq_freeze_lock); } EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ad2b10c4a0797..bb0ac8cbbb4c0 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -655,7 +655,7 @@ struct request_queue { spinlock_t unused_hctx_lock; int bypass_depth; - atomic_t mq_freeze_depth; + int mq_freeze_depth; #if defined(CONFIG_BLK_DEV_BSG) bsg_job_fn *bsg_job_fn; @@ -668,6 +668,11 @@ struct request_queue { #endif struct rcu_head rcu_head; wait_queue_head_t mq_freeze_wq; + /* + * Protect concurrent access to q_usage_counter by + * percpu_ref_kill() and percpu_ref_reinit(). + */ + struct mutex mq_freeze_lock; struct percpu_ref q_usage_counter; struct list_head all_q_node; -- 2.25.1

1 1

[PATCH kernel-4.19] blk-mq: fix hang caused by freeze/unfreeze sequence
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Bob Liu <bob.liu(a)oracle.com> mainline inclusion from mainline-v5.2-rc2 commit 7996a8b5511a72465b0b286763c2d8f412b8874a category: bugfix bugzilla: 173119 CVE: NA ----------------------------------------------- The following is a description of a hang in blk_mq_freeze_queue_wait(). The hang happens on attempt to freeze a queue while another task does queue unfreeze. The root cause is an incorrect sequence of percpu_ref_resurrect() and percpu_ref_kill() and as a result those two can be swapped: CPU#0 CPU#1 ---------------- ----------------- q1 = blk_mq_init_queue(shared_tags) q2 = blk_mq_init_queue(shared_tags): blk_mq_add_queue_tag_set(shared_tags): blk_mq_update_tag_set_depth(shared_tags): list_for_each_entry() blk_mq_freeze_queue(q1) > percpu_ref_kill() > blk_mq_freeze_queue_wait() blk_cleanup_queue(q1) blk_mq_freeze_queue(q1) > percpu_ref_kill() ^^^^^^ freeze_depth can't guarantee the order blk_mq_unfreeze_queue() > percpu_ref_resurrect() > blk_mq_freeze_queue_wait() ^^^^^^ Hang here!!!! This wrong sequence raises kernel warning: percpu_ref_kill_and_confirm called more than once on blk_queue_usage_counter_release! WARNING: CPU: 0 PID: 11854 at lib/percpu-refcount.c:336 percpu_ref_kill_and_confirm+0x99/0xb0 But the most unpleasant effect is a hang of a blk_mq_freeze_queue_wait(), which waits for a zero of a q_usage_counter, which never happens because percpu-ref was reinited (instead of being killed) and stays in PERCPU state forever. How to reproduce: - "insmod null_blk.ko shared_tags=1 nr_devices=0 queue_mode=2" - cpu0: python Script.py 0; taskset the corresponding process running on cpu0 - cpu1: python Script.py 1; taskset the corresponding process running on cpu1 Script.py: ------ #!/usr/bin/python3 import os import sys while True: on = "echo 1 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] off = "echo 0 > /sys/kernel/config/nullb/%s/power" % sys.argv[1] os.system(on) os.system(off) ------ This bug was first reported and fixed by Roman, previous discussion: [1] Message id: 1443287365-4244-7-git-send-email-akinobu.mita(a)gmail.com [2] Message id: 1443563240-29306-6-git-send-email-tj(a)kernel.org [3] https://patchwork.kernel.org/patch/9268199/ Reviewed-by: Hannes Reinecke <hare(a)suse.com> Reviewed-by: Ming Lei <ming.lei(a)redhat.com> Reviewed-by: Bart Van Assche <bvanassche(a)acm.org> Reviewed-by: Christoph Hellwig <hch(a)lst.de> Signed-off-by: Roman Pen <roman.penyaev(a)profitbricks.com> Signed-off-by: Bob Liu <bob.liu(a)oracle.com> Signed-off-by: Jens Axboe <axboe(a)kernel.dk> Signed-off-by: Yu Kuai <yukuai3(a)huawei.com> Reviewed-by: Hou Tao <houtao1(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- block/blk-core.c | 3 ++- block/blk-mq.c | 19 ++++++++++--------- include/linux/blkdev.h | 7 ++++++- 3 files changed, 18 insertions(+), 11 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 4b63336465306..34456f2bf45c3 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -955,7 +955,7 @@ int blk_queue_enter(struct request_queue *q, blk_mq_req_flags_t flags) smp_rmb(); wait_event(q->mq_freeze_wq, - (atomic_read(&q->mq_freeze_depth) == 0 && + (!q->mq_freeze_depth && (pm || !blk_queue_pm_only(q))) || blk_queue_dying(q)); if (blk_queue_dying(q)) @@ -1072,6 +1072,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id, queue_flag_set_unlocked(QUEUE_FLAG_BYPASS, q); init_waitqueue_head(&q->mq_freeze_wq); + mutex_init(&q->mq_freeze_lock); /* * Init percpu_ref in atomic mode so that it's faster to shutdown. diff --git a/block/blk-mq.c b/block/blk-mq.c index f684053ecd51f..dc96754abc2cd 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -136,13 +136,14 @@ void blk_mq_in_flight_rw(struct request_queue *q, struct hd_struct *part, void blk_freeze_queue_start(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_inc_return(&q->mq_freeze_depth); - if (freeze_depth == 1) { + mutex_lock(&q->mq_freeze_lock); + if (++q->mq_freeze_depth == 1) { percpu_ref_kill(&q->q_usage_counter); + mutex_unlock(&q->mq_freeze_lock); if (q->mq_ops) blk_mq_run_hw_queues(q, false); + } else { + mutex_unlock(&q->mq_freeze_lock); } } EXPORT_SYMBOL_GPL(blk_freeze_queue_start); @@ -193,14 +194,14 @@ EXPORT_SYMBOL_GPL(blk_mq_freeze_queue); void blk_mq_unfreeze_queue(struct request_queue *q) { - int freeze_depth; - - freeze_depth = atomic_dec_return(&q->mq_freeze_depth); - WARN_ON_ONCE(freeze_depth < 0); - if (!freeze_depth) { + mutex_lock(&q->mq_freeze_lock); + q->mq_freeze_depth--; + WARN_ON_ONCE(q->mq_freeze_depth < 0); + if (!q->mq_freeze_depth) { percpu_ref_reinit(&q->q_usage_counter); wake_up_all(&q->mq_freeze_wq); } + mutex_unlock(&q->mq_freeze_lock); } EXPORT_SYMBOL_GPL(blk_mq_unfreeze_queue); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 1ce80e23eeab1..376f5dee46fce 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -660,7 +660,7 @@ struct request_queue { spinlock_t unused_hctx_lock; int bypass_depth; - atomic_t mq_freeze_depth; + int mq_freeze_depth; #if defined(CONFIG_BLK_DEV_BSG) bsg_job_fn *bsg_job_fn; @@ -673,6 +673,11 @@ struct request_queue { #endif struct rcu_head rcu_head; wait_queue_head_t mq_freeze_wq; + /* + * Protect concurrent access to q_usage_counter by + * percpu_ref_kill() and percpu_ref_reinit(). + */ + struct mutex mq_freeze_lock; struct percpu_ref q_usage_counter; struct list_head all_q_node; -- 2.25.1

1 0

[PATCH kernel-4.19 00/14] backport linux-4.19.202
by Yang Yingliang 16 Aug '21

16 Aug '21

Axel Lin (1): regulator: rt5033: Fix n_voltages settings for BUCK and LDO Daniel Jordan (2): padata: validate cpumask without removed CPU during offline padata: add separate cpuhp node for CPUHP_PADATA_DEAD Goldwyn Rodrigues (1): btrfs: mark compressed range uptodate only if all bio succeed Greg Kroah-Hartman (3): Revert "Bluetooth: Shutdown controller after workqueues are flushed or cancelled" Revert "watchdog: iTCO_wdt: Account for rebooting on second timeout" Linux 4.19.202 Guenter Roeck (1): spi: mediatek: Fix fifo transfer Jani Nikula (1): drm/i915: Ensure intel_engine_init_execlist() builds with Clang Jia He (1): qed: fix possible unpaired spin_{un}lock_bh in _qed_mcp_cmd_and_union() Kyle Russell (1): ASoC: tlv320aic31xx: fix reversed bclk/wclk master bits Pravin B Shelar (1): net: Fix zero-copy head len calculation. Sudeep Holla (1): firmware: arm_scmi: Ensure drivers provide a probe function Takashi Iwai (1): r8152: Fix potential PM refcount imbalance Makefile | 2 +- drivers/firmware/arm_scmi/bus.c | 3 +++ drivers/gpu/drm/i915/intel_engine_cs.c | 2 +- drivers/net/ethernet/qlogic/qed/qed_mcp.c | 23 ++++++++++++++----- drivers/net/usb/r8152.c | 3 ++- drivers/spi/spi-mt65xx.c | 19 ++++----------- drivers/watchdog/iTCO_wdt.c | 12 +++------- fs/btrfs/compression.c | 3 +-- include/linux/cpuhotplug.h | 1 + include/linux/mfd/rt5033-private.h | 4 ++-- include/linux/padata.h | 6 +++-- kernel/padata.c | 28 ++++++++++++++++------- net/bluetooth/hci_core.c | 16 ++++++------- net/core/skbuff.c | 5 +++- sound/soc/codecs/tlv320aic31xx.h | 4 ++-- 15 files changed, 74 insertions(+), 57 deletions(-) -- 2.25.1

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[PATCH openEuler-1.0-LTS v2 0/5] Introduce default passthrough mode for some SoCs
by Hanjun Guo 16 Aug '21

16 Aug '21

Extended the SMMU_BYPASS_DEV to support SMMU default bypass for some CPU SoCs which the SMMU is not functional well in address translation mode. This patch set based on openEuler kernel LTS 1.0. v2: Adding another patch which other four patches based on. Thanks! Cc: Guo Hui <guohui(a)uniontech.com> Cc: Cheng Jian <cj.chengjian(a)huawei.com> Cc: Zhen Lei <thunder.leizhen(a)huawei.com> Cc: Xiuqi Xie <xiexiuqi(a)huawei.com> Guo Hui (1): arm64: Add MIDR encoding for PHYTIUM CPUs Hanjun Guo (3): arm64: phytium: using MIDR_PHYTIUM_FT2000PLUS instead of ARM_CPU_IMP_PHYTIUM iommu: dev_bypass: cleanup dev bypass code iommu: smmuv2: Using the SMMU_BYPASS_DEV to bypass SMMU for some SoCs Weilong Chen (1): arm64: Add MIDR encoding for HiSilicon Taishan CPUs arch/arm64/include/asm/cputype.h | 7 +++++++ arch/arm64/kernel/topology.c | 6 +++--- drivers/iommu/Kconfig | 14 +++++++++++--- drivers/iommu/arm-smmu-v3.c | 2 +- drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 13 ++++--------- drivers/usb/host/xhci-pci.c | 4 +++- 7 files changed, 57 insertions(+), 17 deletions(-) -- 1.7.12.4

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[PATCH kernel-4.19 0/4] Introduce default passthrough mode for some SoCs
by Hanjun Guo 16 Aug '21

16 Aug '21

Extended the SMMU_BYPASS_DEV to support SMMU default bypass for some CPU SoCs which the SMMU is not functional well in address translation mode. This is the version for 4.19 kernel. Guo Hui, if you didn't test patchset based on 1.0 LTS kernel, you can just apply this patch set instead. Thanks! Cc: Guo Hui <guohui(a)uniontech.com> Cc: Cheng Jian <cj.chengjian(a)huawei.com> Cc: Zhen Lei <thunder.leizhen(a)huawei.com> Cc: Xiuqi Xie <xiexiuqi(a)huawei.com> Guo Hui (1): arm64: Add MIDR encoding for PHYTIUM CPUs Hanjun Guo (3): arm64: phytium: using MIDR_PHYTIUM_FT2000PLUS instead of ARM_CPU_IMP_PHYTIUM iommu: dev_bypass: cleanup dev bypass code iommu: smmuv2: Using the SMMU_BYPASS_DEV to bypass SMMU for some SoCs arch/arm64/include/asm/cputype.h | 5 +++++ arch/arm64/kernel/topology.c | 6 +++--- drivers/iommu/Kconfig | 14 +++++++++++--- drivers/iommu/arm-smmu-v3.c | 2 +- drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 13 ++++--------- drivers/usb/host/xhci-pci.c | 4 +++- 7 files changed, 55 insertions(+), 17 deletions(-) -- 1.7.12.4

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[PATCH openEuler-1.0-LTS 0/4] Introduce default passthrough mode for some SoCs
by Hanjun Guo 16 Aug '21

16 Aug '21

Extended the SMMU_BYPASS_DEV to support SMMU default bypass for some CPU SoCs which the SMMU is not functional well in address translation mode. This patch set based on openEuler kernel LTS 1.0 Guo Hui, could you please test this patch set? as it's based on openEuler kernel LTS 1.0, you can apply patches 2~4/4 for 4.19 kernel. Thanks! Cc: Guo Hui <guohui(a)uniontech.com> Cc: Cheng Jian <cj.chengjian(a)huawei.com> Cc: Zhen Lei <thunder.leizhen(a)huawei.com> Cc: Xiuqi Xie <xiexiuqi(a)huawei.com> Guo Hui (1): arm64: Add MIDR encoding for PHYTIUM CPUs Hanjun Guo (3): arm64: phytium: using MIDR_PHYTIUM_FT2000PLUS instead of ARM_CPU_IMP_PHYTIUM iommu: dev_bypass: cleanup dev bypass code iommu: smmuv2: Using the SMMU_BYPASS_DEV to bypass SMMU for some SoCs arch/arm64/include/asm/cputype.h | 5 +++++ arch/arm64/kernel/topology.c | 6 +++--- drivers/iommu/Kconfig | 14 +++++++++++--- drivers/iommu/arm-smmu-v3.c | 2 +- drivers/iommu/arm-smmu.c | 28 ++++++++++++++++++++++++++++ drivers/iommu/iommu.c | 13 ++++--------- drivers/usb/host/xhci-pci.c | 4 +++- 7 files changed, 55 insertions(+), 17 deletions(-) -- 1.7.12.4

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[PATCH kernel-4.19] config: Enable CONFIG_UCE_KERNEL_RECOVERY by default
by Yang Yingliang 16 Aug '21

16 Aug '21

hulk inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I44REB CVE: NA -------------------------------- Enable CONFIG_UCE_KERNEL_RECOVERY by default. Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- arch/arm64/configs/hulk_defconfig | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/arm64/configs/hulk_defconfig b/arch/arm64/configs/hulk_defconfig index 19cb619927129..c340b5408e9d3 100644 --- a/arch/arm64/configs/hulk_defconfig +++ b/arch/arm64/configs/hulk_defconfig @@ -548,6 +548,7 @@ CONFIG_CPU_PM=y CONFIG_ARCH_HIBERNATION_POSSIBLE=y CONFIG_ARCH_HIBERNATION_HEADER=y CONFIG_ARCH_SUSPEND_POSSIBLE=y +CONFIG_UCE_KERNEL_RECOVERY=y # # CPU Power Management -- 2.25.1

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[PATCH kernel-4.19] EDAC/ghes: Remove intermediate buffer pvt->detail_location
by Yang Yingliang 16 Aug '21

16 Aug '21

From: Robert Richter <rrichter(a)marvell.com> mainline inclusion from mainline-v5.4-rc1 commit 501eb40 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I45QJK?from=project-issue CVE: NA -------------------------------- detail_location[] is used to collect two location strings so they can be passed as one to trace_mc_event(). Instead of having an extra copy step, assemble the location string in other_detail[] from the beginning. Using other_detail[] to call trace_mc_event() is now the same as in edac_mc.c and code can be unified. Signed-off-by: Robert Richter <rrichter(a)marvell.com> Signed-off-by: Borislav Petkov <bp(a)suse.de> Reviewed-by: James Morse <james.morse(a)arm.com> Reviewed-by: Mauro Carvalho Chehab <mchehab+samsung(a)kernel.org> Cc: "linux-edac(a)vger.kernel.org" <linux-edac(a)vger.kernel.org> Cc: Tony Luck <tony.luck(a)intel.com> Link: https://lkml.kernel.org/r/20191106093239.25517-12-rrichter@marvell.com Signed-off-by: Xiongfeng Wang <wangxiongfeng2(a)huawei.com> Reviewed-by: Hanjun Guo <guohanjun(a)huawei.com> Signed-off-by: Yang Yingliang <yangyingliang(a)huawei.com> --- drivers/edac/ghes_edac.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/edac/ghes_edac.c b/drivers/edac/ghes_edac.c index 78c339da19b56..f7f8feb4498bc 100644 --- a/drivers/edac/ghes_edac.c +++ b/drivers/edac/ghes_edac.c @@ -23,8 +23,7 @@ struct ghes_edac_pvt { struct mem_ctl_info *mci; /* Buffers for the error handling routine */ - char detail_location[240]; - char other_detail[160]; + char other_detail[400]; char msg[80]; }; @@ -340,6 +339,8 @@ void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err) /* All other fields are mapped on e->other_detail */ p = pvt->other_detail; + p += snprintf(p, sizeof(pvt->other_detail), + "APEI location: %s ", e->location); if (mem_err->validation_bits & CPER_MEM_VALID_ERROR_STATUS) { u64 status = mem_err->error_status; @@ -420,12 +421,10 @@ void ghes_edac_report_mem_error(int sev, struct cper_sec_mem_err *mem_err) grain_bits = fls_long(e->grain - 1); /* Generate the trace event */ - snprintf(pvt->detail_location, sizeof(pvt->detail_location), - "APEI location: %s %s", e->location, e->other_detail); trace_mc_event(type, e->msg, e->label, e->error_count, mci->mc_idx, e->top_layer, e->mid_layer, e->low_layer, (e->page_frame_number << PAGE_SHIFT) | e->offset_in_page, - grain_bits, e->syndrome, pvt->detail_location); + grain_bits, e->syndrome, e->other_detail); edac_raw_mc_handle_error(type, mci, e); spin_unlock_irqrestore(&ghes_lock, flags); -- 2.25.1

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