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[PATCH OLK-6.6] cgroup/rstat: avoid disabling irqs for O(num_cpu)
by Cai Xinchen 30 Jul '26

30 Jul '26

From: Eric Dumazet <edumazet(a)google.com> mainline inclusion from mainline-v6.15-rc1 commit 0efc297a3c4974dbd609ee36fc6345720b6ca735 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9685 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- cgroup_rstat_flush_locked() grabs the irq safe cgroup_rstat_lock while iterating all possible cpus. It only drops the lock if there is scheduler or spin lock contention. If neither, then interrupts can be disabled for a long time. On large machines this can disable interrupts for a long enough time to drop network packets. On 400+ CPU machines I've seen interrupt disabled for over 40 msec. Prevent rstat from disabling interrupts while processing all possible cpus. Instead drop and reacquire cgroup_rstat_lock for each cpu. This approach was previously discussed in https://lore.kernel.org/lkml/ZBz%2FV5a7%2F6PZeM7S@slm.duckdns.org/, though this was in the context of an non-irq rstat spin lock. Benchmark this change with: 1) a single stat_reader process with 400 threads, each reading a test memcg's memory.stat repeatedly for 10 seconds. 2) 400 memory hog processes running in the test memcg and repeatedly charging memory until oom killed. Then they repeat charging and oom killing. v6.14-rc6 with CONFIG_IRQSOFF_TRACER with stat_reader and hogs, finds interrupts are disabled by rstat for 45341 usec: # => started at: _raw_spin_lock_irq # => ended at: cgroup_rstat_flush # # # _------=> CPU# # / _-----=> irqs-off/BH-disabled # | / _----=> need-resched # || / _---=> hardirq/softirq # ||| / _--=> preempt-depth # |||| / _-=> migrate-disable # ||||| / delay # cmd pid |||||| time | caller # \ / |||||| \ | / stat_rea-96532 52d.... 0us*: _raw_spin_lock_irq stat_rea-96532 52d.... 45342us : cgroup_rstat_flush stat_rea-96532 52d.... 45342us : tracer_hardirqs_on <-cgroup_rstat_flush stat_rea-96532 52d.... 45343us : <stack trace> => memcg1_stat_format => memory_stat_format => memory_stat_show => seq_read_iter => vfs_read => ksys_read => do_syscall_64 => entry_SYSCALL_64_after_hwframe With this patch the CONFIG_IRQSOFF_TRACER doesn't find rstat to be the longest holder. The longest irqs-off holder has irqs disabled for 4142 usec, a huge reduction from previous 45341 usec rstat finding. Running stat_reader memory.stat reader for 10 seconds: - without memory hogs: 9.84M accesses => 12.7M accesses - with memory hogs: 9.46M accesses => 11.1M accesses The throughput of memory.stat access improves. The mode of memory.stat access latency after grouping by of 2 buckets: - without memory hogs: 64 usec => 16 usec - with memory hogs: 64 usec => 8 usec The memory.stat latency improves. Signed-off-by: Eric Dumazet <edumazet(a)google.com> Signed-off-by: Greg Thelen <gthelen(a)google.com> Tested-by: Greg Thelen <gthelen(a)google.com> Acked-by: Michal Koutný <mkoutny(a)suse.com> Reviewed-by: Yosry Ahmed <yosry.ahmed(a)linux.dev> Signed-off-by: Tejun Heo <tj(a)kernel.org> Conflicts: kernel/cgroup/rstat.c [Use spin_(un)lock_irq instead of __cgroup_rstat_(un)lock in 6.6] Signed-off-by: Cai Xinchen <caixinchen1(a)huawei.com> --- kernel/cgroup/rstat.c | 10 ++++------ 1 file changed, 4 insertions(+), 6 deletions(-) diff --git a/kernel/cgroup/rstat.c b/kernel/cgroup/rstat.c index b589868cc85c..ea5a21dc9df3 100644 --- a/kernel/cgroup/rstat.c +++ b/kernel/cgroup/rstat.c @@ -205,12 +205,10 @@ static void cgroup_rstat_flush_locked(struct cgroup *cgrp) raw_spin_unlock_irqrestore(cpu_lock, flags); /* play nice and yield if necessary */ - if (need_resched() || spin_needbreak(&cgroup_rstat_lock)) { - spin_unlock_irq(&cgroup_rstat_lock); - if (!cond_resched()) - cpu_relax(); - spin_lock_irq(&cgroup_rstat_lock); - } + spin_unlock_irq(&cgroup_rstat_lock); + if (!cond_resched()) + cpu_relax(); + spin_lock_irq(&cgroup_rstat_lock); } } -- 2.18.0.huawei.25

2 1

[PATCH OLK-6.6] udf: validate free block extents against the partition length
by Lai Zewei 30 Jul '26

30 Jul '26

stable inclusion from stable-v6.6.145 commit fb49099206c5c57af28a157249fa7bcb5518f99e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16620 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array. Fixes: 56e69e59751d ("udf: prevent integer overflow in udf_bitmap_free_blocks()") Cc: stable(a)vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito(a)gmail.com> Link: https://patch.msgid.link/20260515142327.1120767-1-michael.bommarito@gmail.c… Signed-off-by: Jan Kara <jack(a)suse.cz> Signed-off-by: Lai Zewei <laizewei3(a)huawei.com> --- fs/udf/balloc.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/fs/udf/balloc.c b/fs/udf/balloc.c index f5de2030e769..e3bf8122b7dc 100644 --- a/fs/udf/balloc.c +++ b/fs/udf/balloc.c @@ -82,8 +82,9 @@ static int __load_block_bitmap(struct super_block *sb, int nr_groups = bitmap->s_nr_groups; if (block_group >= nr_groups) { - udf_debug("block_group (%u) > nr_groups (%d)\n", + udf_debug("block_group (%u) >= nr_groups (%d)\n", block_group, nr_groups); + return -EFSCORRUPTED; } if (bitmap->s_block_bitmap[block_group]) { @@ -679,7 +680,7 @@ void udf_free_blocks(struct super_block *sb, struct inode *inode, if (check_add_overflow(bloc->logicalBlockNum, offset, &blk) || check_add_overflow(blk, count, &blk) || - bloc->logicalBlockNum + count > map->s_partition_len) { + blk > map->s_partition_len) { udf_debug("Invalid request to free blocks: (%d, %u), off %u, " "len %u, partition len %u\n", partition, bloc->logicalBlockNum, offset, count, -- 2.52.0

2 7

[PATCH OLK-6.6] iov_iter: Fix potential underflow in iov_iter_extract_xarray_pages()
by Chen Jinghuang 30 Jul '26

30 Jul '26

From: David Howells <dhowells(a)redhat.com> mainline inclusion from mainline-v7.2-rc2 commit 55f4bb9373ca4a521f3b0119366db92715a39b81 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9684 Reference: https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/comm… -------------------------------- In iov_iter_extract_xarray_pages(), if no pages are extracted because there's a hole (or something otherwise unextractable) in the xarray, then the calculation of maxsize at the end can go wrong if the starting offset is not zero. Fix this by returning 0 in such a case and freeing the page array if allocated here rather than being passed in. Note that in the near future, ITER_XARRAY should be removed. Fixes: 7d58fe731028 ("iov_iter: Add a function to extract a page list from an iterator") Link: https://sashiko.dev/#/patchset/20260608145432.681865-1-dhowells%40redhat.com Link: https://sashiko.dev/#/patchset/20260616100821.2062304-1-dhowells%40redhat.c… Signed-off-by: David Howells <dhowells(a)redhat.com> Link: https://patch.msgid.link/20260625140640.3116900-6-dhowells@redhat.com Reviewed-by: Christoph Hellwig <hch(a)lst.de> cc: Paulo Alcantara <pc(a)manguebit.org> cc: Matthew Wilcox <willy(a)infradead.org> cc: Christoph Hellwig <hch(a)infradead.org> cc: Jens Axboe <axboe(a)kernel.dk> cc: Mike Marshall <hubcap(a)omnibond.com> cc: netfs(a)lists.linux.dev cc: linux-fsdevel(a)vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner(a)kernel.org> Conflicts: lib/iov_iter.c [a little context conflict] Signed-off-by: Chen Jinghuang <chenjinghuang2(a)huawei.com> --- lib/iov_iter.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 0b8fc9831225..a4cc8d68b409 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1625,6 +1625,7 @@ static ssize_t iov_iter_extract_xarray_pages(struct iov_iter *i, struct page *page, **p; unsigned int nr = 0, offset; loff_t pos = i->xarray_start + i->iov_offset; + bool will_alloc = !*pages; pgoff_t index = pos >> PAGE_SHIFT; XA_STATE(xas, i->xarray, index); @@ -1653,6 +1654,14 @@ static ssize_t iov_iter_extract_xarray_pages(struct iov_iter *i, } rcu_read_unlock(); + if (!nr) { + if (will_alloc) { + kvfree(*pages); + *pages = NULL; + } + return 0; + } + maxsize = min_t(size_t, nr * PAGE_SIZE - offset, maxsize); iov_iter_advance(i, maxsize); return maxsize; -- 2.34.1

2 1

[PATCH OLK-6.6] bpf: Allow LPM map access from sleepable BPF programs
by Tengda Wu 30 Jul '26

30 Jul '26

From: Vlad Poenaru <vlad.wing(a)gmail.com> stable inclusion from stable-v6.6.145 commit ec662a8b2cde01e76b37ccd4b992d0342299e69c category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16648 CVE: CVE-2026-64352 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 2f884d371fafea137afea504d49ee4a7c8d7985b ] trie_lookup_elem() annotates its rcu_dereference_check() walks with only rcu_read_lock_bh_held(). Because rcu_dereference_check(p, c) resolves to "c || rcu_read_lock_held()", this passes for XDP/NAPI and classic RCU readers but fails for sleepable BPF programs, which enter via __bpf_prog_enter_sleepable() and hold only rcu_read_lock_trace(). trie_update_elem() and trie_delete_elem() have the same problem in a different form: they walk the trie with plain rcu_dereference(), which asserts rcu_read_lock_held() unconditionally. Both are reachable from sleepable BPF programs via the bpf_map_update_elem / bpf_map_delete_elem helpers, and from the syscall path under classic rcu_read_lock(). In the writer paths the trie is actually protected by trie->lock (an rqspinlock taken across the walk); we never relied on the RCU read-side lock to keep nodes alive there. A sleepable LSM hook that ends up touching an LPM trie therefore triggers lockdep on debug kernels: ============================= WARNING: suspicious RCU usage 7.1.0-... Tainted: G E ----------------------------- kernel/bpf/lpm_trie.c:249 suspicious rcu_dereference_check() usage! 1 lock held by net_tests/540: #0: (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: __bpf_prog_enter_sleepable+0x26/0x280 Call Trace: dump_stack_lvl lockdep_rcu_suspicious trie_lookup_elem bpf_prog_..._enforce_security_socket_connect bpf_trampoline_... security_socket_connect __sys_connect do_syscall_64 This is lockdep-only -- no UAF, since Tasks Trace RCU does serialize against the trie's reclaim path -- but it spams the console once per distinct callsite on every debug kernel running a sleepable BPF LSM that touches an LPM trie, which is increasingly common. For the lookup path, switch the rcu_dereference_check() annotation from rcu_read_lock_bh_held() to bpf_rcu_lock_held(), which accepts all three contexts (classic, BH, Tasks Trace). Other map types already follow this convention. For trie_update_elem() and trie_delete_elem(), annotate the walks as rcu_dereference_protected(*p, 1) -- matching trie_free() in the same file -- since trie->lock is held across the walk. rqspinlock has no lockdep_map, so the predicate degenerates to '1' rather than lockdep_is_held(&trie->lock); the protection is real but not machine-verifiable. trie_get_next_key() also uses bare rcu_dereference() but is reachable only from the BPF syscall, which holds classic rcu_read_lock() before dispatching, so it is left untouched. Fixes: 694cea395fde ("bpf: Allow RCU-protected lookups to happen from bh context") Cc: stable(a)vger.kernel.org Signed-off-by: Vlad Poenaru <vlad.wing(a)gmail.com> Reviewed-by: Emil Tsalapatis <emil(a)etsalapatis.com> Link: https://lore.kernel.org/r/20260609135558.193287-2-vlad.wing@gmail.com Signed-off-by: Alexei Starovoitov <ast(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Tengda Wu <wutengda2(a)huawei.com> --- kernel/bpf/lpm_trie.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/lpm_trie.c b/kernel/bpf/lpm_trie.c index c4f1d465ae35..7c7cacf9fa59 100644 --- a/kernel/bpf/lpm_trie.c +++ b/kernel/bpf/lpm_trie.c @@ -236,7 +236,7 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key) /* Start walking the trie from the root node ... */ - for (node = rcu_dereference_check(trie->root, rcu_read_lock_bh_held()); + for (node = rcu_dereference_check(trie->root, bpf_rcu_lock_held()); node;) { unsigned int next_bit; size_t matchlen; @@ -270,7 +270,7 @@ static void *trie_lookup_elem(struct bpf_map *map, void *_key) */ next_bit = extract_bit(key->data, node->prefixlen); node = rcu_dereference_check(node->child[next_bit], - rcu_read_lock_bh_held()); + bpf_rcu_lock_held()); } if (!found) -- 2.34.1

2 1

[PATCH OLK-6.6] perf/core: Detach event groups during remove_on_exec
by Luo Gengkun 30 Jul '26

30 Jul '26

From: Taeyang Lee <0wn(a)theori.io> stable inclusion from stable-v6.6.145 commit 4cdb1b3ab96eb1b7eb70bc5c82fede334bd60df2 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16858 CVE: CVE-2026-64556 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… ---------------------------------------------------------------------- [ Upstream commit 037a3c43edfb597665dd34457cd22b14692f2ba3 ] perf_event_remove_on_exec() removes events by calling perf_event_exit_event(). For top-level events, this removes the event from the context with DETACH_EXIT only. This can leave inconsistent group state when a removed event is a group leader and the group contains siblings without remove_on_exec. If the group was active, the surviving siblings can remain active and attached to the removed leader's sibling list, but are no longer represented by a valid group leader on the PMU context active lists. A later close of the removed leader uses DETACH_GROUP and can promote the still-active siblings from this stale group state. The next schedule-in can then add an already-linked active_list entry again, corrupting the PMU context active list. With DEBUG_LIST enabled, this is caught as a list_add double-add in merge_sched_in(). Fix this by detaching group relationships when remove_on_exec removes an event. This preserves the existing task-exit and revoke behavior, while ensuring surviving siblings are ungrouped before the removed event leaves the context. Fixes: 2e498d0a74e5 ("perf: Add support for event removal on exec") Signed-off-by: Taeyang Lee <0wn(a)theori.io> Signed-off-by: Peter Zijlstra (Intel) <peterz(a)infradead.org> Link: https://patch.msgid.link/ai65GgZcC0LAlWLG@Taeyangs-MacBook-Pro.local Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Luo Gengkun <luogengkun2(a)huawei.com> --- kernel/events/core.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index dbfe7f054d4b..6916dc78b0e7 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4451,7 +4451,8 @@ static void perf_event_enable_on_exec(struct perf_event_context *ctx) static void perf_remove_from_owner(struct perf_event *event); static void perf_event_exit_event(struct perf_event *event, - struct perf_event_context *ctx); + struct perf_event_context *ctx, + unsigned long detach_flags); /* * Removes all events from the current task that have been marked @@ -4478,7 +4479,7 @@ static void perf_event_remove_on_exec(struct perf_event_context *ctx) modified = true; - perf_event_exit_event(event, ctx); + perf_event_exit_event(event, ctx, DETACH_GROUP); } raw_spin_lock_irqsave(&ctx->lock, flags); @@ -13224,10 +13225,11 @@ static void sync_child_event(struct perf_event *child_event) } static void -perf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx) +perf_event_exit_event(struct perf_event *event, + struct perf_event_context *ctx, + unsigned long detach_flags) { struct perf_event *parent_event = event->parent; - unsigned long detach_flags = 0; if (parent_event) { /* @@ -13242,7 +13244,7 @@ perf_event_exit_event(struct perf_event *event, struct perf_event_context *ctx) * Do destroy all inherited groups, we don't care about those * and being thorough is better. */ - detach_flags = DETACH_GROUP | DETACH_CHILD; + detach_flags |= DETACH_GROUP | DETACH_CHILD; mutex_lock(&parent_event->child_mutex); } @@ -13321,7 +13323,7 @@ static void perf_event_exit_task_context(struct task_struct *child) perf_event_task(child, child_ctx, 0); list_for_each_entry_safe(child_event, next, &child_ctx->event_list, event_entry) - perf_event_exit_event(child_event, child_ctx); + perf_event_exit_event(child_event, child_ctx, 0); mutex_unlock(&child_ctx->mutex); -- 2.34.1

2 1

[PATCH OLK-5.10] KVM: x86/mmu: Ensure hugepage is in by slot before checking max mapping level
by Zhang Kunbo 29 Jul '26

29 Jul '26

From: Sean Christopherson <seanjc(a)google.com> stable inclusion from stable-v6.6.144 commit 48b91ed7e22bb82571c34f8b80b6ecdc90a6fab8 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16138 CVE: CVE-2026-63807 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit ef057cbf825e03b63f6edf5980f96abf3c53089d upstream. When recovering hugepages in the shadow MMU, verify that the base gfn of the shadow page is actually contained within the target memslot, *before* querying the max mapping level given the shadow page's gfn. Failure to pre-check the validity of the gfn can lead to an out-of-bounds access to the slot's lpage_info (which typically manifests as a host #PF because the lpage_info is vmalloc'd) if the guest creates a hugepage mapping (in its PTEs) that extends "below" the bounds of a memslot. When faulting in memory for a guest, and the size of the guest mapping is greater than KVM's (current) max mapping, then KVM will create a "direct" shadow page (direct in that there are no gPTEs to shadow, and so the target gfn is a direct calculation given the base gfn of the shadow page). The hugepage recovery flow looks for such direct shadow pages, as forcing 4KiB mappings when dirty logging generates the guest > host mapping size case. When the 4KiB restriction is lifted, then KVM can replace the shadow page with a hugepage. But if KVM originally used a smaller mapping than the guest because the range of memory covered by the guest hugepage exceeds the bounds of a memslot, then KVM will link a direct shadow page with a gfn that is outside the bounds of the memslot being used to fault in memory. The rmap entry added for the leaf mapping is correct and within bounds, but the gfn of the leaf SPTE's parent shadow page will be out of bounds. BUG: unable to handle page fault for address: ffffc90000806ffc #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 100000067 P4D 100000067 PUD 1002a7067 PMD 10612f067 PTE 0 Oops: Oops: 0000 [#1] SMP CPU: 13 UID: 1000 PID: 757 Comm: mmu_stress_test Not tainted 7.1.0-rc1-48ce1e26eace-x86_pir_to_irr_comments-vm #341 PREEMPT Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:kvm_mmu_max_mapping_level+0x79/0x2b0 [kvm] Call Trace: <TASK> kvm_mmu_recover_huge_pages+0x21b/0x320 [kvm] kvm_set_memslot+0x1ee/0x590 [kvm] kvm_set_memory_region.part.0+0x3a1/0x4d0 [kvm] kvm_vm_ioctl+0x9bf/0x15d0 [kvm] __x64_sys_ioctl+0x8a/0xd0 do_syscall_64+0xb7/0xbb0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f21c0f1a9bf </TASK> Don't bother pre-checking the bounds of the potential hugepage, i.e. don't check that e.g. sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level + 1) is also within the memslot, as the checks performed by kvm_mmu_max_mapping_level() are a superset of the basic bounds checks. I.e. pre-checking the full range would be a dubious micro-optimization. Fixes: 9eba50f8d7fc ("KVM: x86/mmu: Consult max mapping level when zapping collapsible SPTEs") Cc: stable(a)vger.kernel.org Cc: David Matlack <dmatlack(a)google.com> Cc: James Houghton <jthoughton(a)google.com> Cc: Alexander Bulekov <bkov(a)amazon.com> Cc: Fred Griffoul <fgriffo(a)amazon.co.uk> Cc: Alexander Graf <graf(a)amazon.de> Cc: David Woodhouse <dwmw(a)amazon.co.uk> Cc: Filippo Sironi <sironi(a)amazon.de> Cc: Ivan Orlov <iorlov(a)amazon.co.uk> Signed-off-by: Sean Christopherson <seanjc(a)google.com> Signed-off-by: Paolo Bonzini <pbonzini(a)redhat.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> conflicts: include/linux/kvm_host.h [context conflicts] Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- arch/x86/kvm/mmu/mmu.c | 18 ++++++++++++------ include/linux/kvm_host.h | 7 ++++++- 2 files changed, 18 insertions(+), 7 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 6ee54414295b..2d71bcd36eca 100755 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6466,13 +6466,19 @@ static bool kvm_mmu_zap_collapsible_spte(struct kvm *kvm, sp = sptep_to_sp(sptep); /* - * We cannot do huge page mapping for indirect shadow pages, - * which are found on the last rmap (level = 1) when not using - * tdp; such shadow pages are synced with the page table in - * the guest, and the guest page table is using 4K page size - * mapping if the indirect sp has level = 1. + * Direct shadow page can be replaced by a hugepage if the host + * mapping level allows it and the memslot maps all of the host + * hugepage. Note! If the memslot maps only part of the + * hugepage, sp->gfn may be below slot->base_gfn, and querying + * the max mapping level would cause an out-of-bounds lpage_info + * access. So the gfn bounds check *must* be done first. + * + * Indirect shadow pages are created when the guest page tables + * are using 4K pages. Since the host mapping is always + * constrained by the page size in the guest, indirect shadow + * pages are never collapsible. */ - if (sp->role.direct && + if (sp->role.direct && is_gfn_in_memslot(slot, sp->gfn) && sp->role.level < kvm_mmu_max_mapping_level(kvm, slot, sp->gfn, PG_LEVEL_NUM)) { kvm_zap_one_rmap_spte(kvm, rmap_head, sptep); diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 3bf870ffc8b7..783be5bb05c8 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -1184,6 +1184,11 @@ int kvm_request_irq_source_id(struct kvm *kvm); void kvm_free_irq_source_id(struct kvm *kvm, int irq_source_id); bool kvm_arch_irqfd_allowed(struct kvm *kvm, struct kvm_irqfd *args); +static inline bool is_gfn_in_memslot(const struct kvm_memory_slot *slot, gfn_t gfn) +{ + return gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages; +} + void kire_arch_cached_data_update(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e); /* @@ -1206,7 +1211,7 @@ try_get_memslot(struct kvm_memslots *slots, int slot_index, gfn_t gfn) slot_index = array_index_nospec(slot_index, slots->used_slots); slot = &slots->memslots[slot_index]; - if (gfn >= slot->base_gfn && gfn < slot->base_gfn + slot->npages) + if (is_gfn_in_memslot(slot, gfn)) return slot; else return NULL; -- 2.34.1

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[PATCH OLK-6.6] drivers/base/memory: fix memory block reference leak in poison accounting
by Lin Ruifeng 29 Jul '26

29 Jul '26

From: Muchun Song <songmuchun(a)bytedance.com> stable inclusion from stable-v6.6.142 commit 686b4283f82cd630fafd7ca9b03dfc080b3ec8fa category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16374 CVE: CVE-2026-64182 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 03a2cc1756a0570f887d624cd6c535ea0cbd4951 upstream. memblk_nr_poison_inc() and memblk_nr_poison_sub() look up a memory block via find_memory_block_by_id(), which acquires a reference to the memory block device. Both helpers use the returned memory block without dropping that reference, leaking the device reference on each successful lookup. Drop the reference after updating nr_hwpoison. Link: https://lore.kernel.org/20260428085219.1316047-3-songmuchun@bytedance.com Fixes: 5033091de814 ("mm/hwpoison: introduce per-memory_block hwpoison counter") Signed-off-by: Muchun Song <songmuchun(a)bytedance.com> Reviewed-by: Miaohe Lin <linmiaohe(a)huawei.com> Acked-by: Oscar Salvador <osalvador(a)suse.de> Acked-by: David Hildenbrand (Arm) <david(a)kernel.org> Cc: Danilo Krummrich <dakr(a)kernel.org> Cc: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Cc: "Huang, Ying" <huang.ying.caritas(a)gmail.com> Cc: Naoya Horiguchi <nao.horiguchi(a)gmail.com> Cc: "Rafael J. Wysocki" <rafael(a)kernel.org> Cc: Vishal Verma <vishal.l.verma(a)intel.com> Cc: <stable(a)vger.kernel.org> Signed-off-by: Andrew Morton <akpm(a)linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Lin Ruifeng <linruifeng4(a)huawei.com> --- drivers/base/memory.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 32a7bbc00599..2196b53a62f7 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -1306,8 +1306,10 @@ void memblk_nr_poison_inc(unsigned long pfn) const unsigned long block_id = pfn_to_block_id(pfn); struct memory_block *mem = find_memory_block_by_id(block_id); - if (mem) + if (mem) { atomic_long_inc(&mem->nr_hwpoison); + put_device(&mem->dev); + } } void memblk_nr_poison_sub(unsigned long pfn, long i) @@ -1315,8 +1317,10 @@ void memblk_nr_poison_sub(unsigned long pfn, long i) const unsigned long block_id = pfn_to_block_id(pfn); struct memory_block *mem = find_memory_block_by_id(block_id); - if (mem) + if (mem) { atomic_long_sub(i, &mem->nr_hwpoison); + put_device(&mem->dev); + } } static unsigned long memblk_nr_poison(struct memory_block *mem) -- 2.34.1

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[PATCH OLK-6.6] spi: qup: fix error pointer deref after DMA setup failure
by Lin Ruifeng 29 Jul '26

29 Jul '26

From: Johan Hovold <johan(a)kernel.org> stable inclusion from stable-v6.6.142 commit 45760b72e84c1a1498f1a8a9047184c85299da20 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16365 CVE: CVE-2026-64170 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit a7e8f3efd50a165ba0189f6dc57f7e51a7d149db ] The driver falls back to PIO mode if DMA setup fails during probe. Make sure to the clear the DMA channel pointers on setup failure to avoid dereferencing an error pointer (or attempting to release a channel a second time) on later probe errors or driver unbind. This issue was flagged by Sashiko when reviewing a devres allocation conversion patch. Fixes: 612762e82ae6 ("spi: qup: Add DMA capabilities") Link: https://sashiko.dev/#/patchset/20260505072909.618363-1-johan%40kernel.org?p… Cc: stable(a)vger.kernel.org # 4.1 Signed-off-by: Johan Hovold <johan(a)kernel.org> Link: https://patch.msgid.link/20260512074334.914735-1-johan@kernel.org Signed-off-by: Mark Brown <broonie(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Lin Ruifeng <linruifeng4(a)huawei.com> --- drivers/spi/spi-qup.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index 1e9cd86d9dcc..fd442062847d 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -967,8 +967,11 @@ static int spi_qup_init_dma(struct spi_controller *host, resource_size_t base) err: dma_release_channel(host->dma_tx); + host->dma_tx = NULL; err_tx: dma_release_channel(host->dma_rx); + host->dma_rx = NULL; + return ret; } -- 2.34.1

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[PATCH OLK-6.6] i2c: stub: Reject I2C block transfers with invalid length
by Lin Ruifeng 29 Jul '26

29 Jul '26

From: Weiming Shi <bestswngs(a)gmail.com> stable inclusion from stable-v6.6.144 commit 1c4ffe6b4f04365485ed58d64c9bb86b46fc9037 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16516 CVE: CVE-2026-64191 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- commit 6036b5067a8199ba7a2dc7b377d4b9dd276d5f9e upstream. The I2C_SMBUS_I2C_BLOCK_DATA case in stub_xfer() uses data->block[0] as the transfer length. The existing check only clamps it to avoid overrunning the chip->words[256] register array, but does not validate it against I2C_SMBUS_BLOCK_MAX (32), which is the limit of the union i2c_smbus_data.block buffer (34 bytes total). The driver is a development/test tool (CONFIG_I2C_STUB=m, not built by default) that must be loaded with a chip_addr= parameter. A local user with access to /dev/i2c-* can issue an I2C_SMBUS ioctl with I2C_SMBUS_I2C_BLOCK_DATA and data->block[0] > 32, causing stub_xfer() to read or write past the end of the union i2c_smbus_data.block buffer: BUG: KASAN: stack-out-of-bounds in stub_xfer (drivers/i2c/i2c-stub.c:223) Read of size 1 at addr ffff88800abcfd92 by task exploit/81 Call Trace: <TASK> stub_xfer (drivers/i2c/i2c-stub.c:223) __i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:593) i2c_smbus_xfer (drivers/i2c/i2c-core-smbus.c:536) i2cdev_ioctl_smbus (drivers/i2c/i2c-dev.c:391) i2cdev_ioctl (drivers/i2c/i2c-dev.c:478) __x64_sys_ioctl (fs/ioctl.c:583) do_syscall_64 (arch/x86/entry/syscall_64.c:94) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> The bug exists because i2c-stub implements .smbus_xfer directly, bypassing the I2C_SMBUS_BLOCK_MAX validation in i2c_smbus_xfer_emulated(). The I2C_SMBUS_BLOCK_DATA case in the same function correctly validates against I2C_SMBUS_BLOCK_MAX, but the I2C_SMBUS_I2C_BLOCK_DATA case does not. Fix by rejecting transfers with data->block[0] == 0 or data->block[0] > I2C_SMBUS_BLOCK_MAX with -EINVAL, consistent with both the I2C_SMBUS_BLOCK_DATA case in the same function and the I2C_SMBUS_I2C_BLOCK_DATA validation in i2c_smbus_xfer_emulated(). Fixes: 4710317891e4 ("i2c-stub: Implement I2C block support") Reported-by: Xiang Mei <xmei5(a)asu.edu> Signed-off-by: Weiming Shi <bestswngs(a)gmail.com> Reviewed-by: Jean Delvare <jdelvare(a)suse.de> Signed-off-by: Wolfram Sang <wsa+renesas(a)sang-engineering.com> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Signed-off-by: Lin Ruifeng <linruifeng4(a)huawei.com> --- drivers/i2c/i2c-stub.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/i2c/i2c-stub.c b/drivers/i2c/i2c-stub.c index d642cad219d9..3a2f472dd6b0 100644 --- a/drivers/i2c/i2c-stub.c +++ b/drivers/i2c/i2c-stub.c @@ -214,6 +214,11 @@ static s32 stub_xfer(struct i2c_adapter *adap, u16 addr, unsigned short flags, * We ignore banks here, because banked chips don't use I2C * block transfers */ + if (data->block[0] == 0 || + data->block[0] > I2C_SMBUS_BLOCK_MAX) { + ret = -EINVAL; + break; + } if (data->block[0] > 256 - command) /* Avoid overrun */ data->block[0] = 256 - command; len = data->block[0]; -- 2.34.1

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[PATCH OLK-5.10] spi: qup: fix error pointer deref after DMA setup failure
by Lin Ruifeng 29 Jul '26

29 Jul '26

From: Johan Hovold <johan(a)kernel.org> stable inclusion from stable-v5.10.259 commit 0bb3bd442f0bdad3932739a61dd6c580c9c1955e category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/16365 CVE: CVE-2026-64170 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit a7e8f3efd50a165ba0189f6dc57f7e51a7d149db ] The driver falls back to PIO mode if DMA setup fails during probe. Make sure to the clear the DMA channel pointers on setup failure to avoid dereferencing an error pointer (or attempting to release a channel a second time) on later probe errors or driver unbind. This issue was flagged by Sashiko when reviewing a devres allocation conversion patch. Fixes: 612762e82ae6 ("spi: qup: Add DMA capabilities") Link: https://sashiko.dev/#/patchset/20260505072909.618363-1-johan%40kernel.org?p… Cc: stable(a)vger.kernel.org # 4.1 Signed-off-by: Johan Hovold <johan(a)kernel.org> Link: https://patch.msgid.link/20260512074334.914735-1-johan@kernel.org Signed-off-by: Mark Brown <broonie(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh(a)linuxfoundation.org> Conflicts: drivers/spi/spi-qup.c [Context Conflicts] Signed-off-by: Lin Ruifeng <linruifeng4(a)huawei.com> --- drivers/spi/spi-qup.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/spi/spi-qup.c b/drivers/spi/spi-qup.c index 2cc9bb413c10..5caf347674f0 100644 --- a/drivers/spi/spi-qup.c +++ b/drivers/spi/spi-qup.c @@ -969,8 +969,10 @@ static int spi_qup_init_dma(struct spi_master *master, resource_size_t base) err: dma_release_channel(master->dma_tx); + master->dma_tx = NULL; err_tx: dma_release_channel(master->dma_rx); + master->dma_rx = NULL; return ret; } -- 2.34.1

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