From: Dave Jiang dave.jiang@intel.com
mainline inclusion from mainline-v5.12-rc1 commit 471b12c43f376d5203dbff0e91316eea11f6f4df category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I4O662 CVE: NA
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When the auxiliary device code is built into the kernel, it can be executed before the auxiliary bus is registered. This causes bus->p to be not allocated and triggers a NULL pointer dereference when the auxiliary bus device gets added with bus_add_device(). Call the auxiliary_bus_init() under driver_init() so the bus is initialized before devices.
Below is the kernel splat for the bug: [ 1.948215] BUG: kernel NULL pointer dereference, address: 0000000000000060 [ 1.950670] #PF: supervisor read access in kernel mode [ 1.950670] #PF: error_code(0x0000) - not-present page [ 1.950670] PGD 0 [ 1.950670] Oops: 0000 1 SMP NOPTI [ 1.950670] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.10.0-intel-nextsvmtest+ #2205 [ 1.950670] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 1.950670] RIP: 0010:bus_add_device+0x64/0x140 [ 1.950670] Code: 00 49 8b 75 20 48 89 df e8 59 a1 ff ff 41 89 c4 85 c0 75 7b 48 8b 53 50 48 85 d2 75 03 48 8b 13 49 8b 85 a0 00 00 00 48 89 de <48> 8 78 60 48 83 c7 18 e8 ef d9 a9 ff 41 89 c4 85 c0 75 45 48 8b [ 1.950670] RSP: 0000:ff46032ac001baf8 EFLAGS: 00010246 [ 1.950670] RAX: 0000000000000000 RBX: ff4597f7414aa680 RCX: 0000000000000000 [ 1.950670] RDX: ff4597f74142bbc0 RSI: ff4597f7414aa680 RDI: ff4597f7414aa680 [ 1.950670] RBP: ff46032ac001bb10 R08: 0000000000000044 R09: 0000000000000228 [ 1.950670] R10: ff4597f741141b30 R11: ff4597f740182a90 R12: 0000000000000000 [ 1.950670] R13: ffffffffa5e936c0 R14: 0000000000000000 R15: 0000000000000000 [ 1.950670] FS: 0000000000000000(0000) GS:ff4597f7bba00000(0000) knlGS:0000000000000000 [ 1.950670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1.950670] CR2: 0000000000000060 CR3: 000000002140c001 CR4: 0000000000f71ef0 [ 1.950670] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1.950670] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 [ 1.950670] PKRU: 55555554 [ 1.950670] Call Trace: [ 1.950670] device_add+0x3ee/0x850 [ 1.950670] __auxiliary_device_add+0x47/0x60 [ 1.950670] idxd_pci_probe+0xf77/0x1180 [ 1.950670] local_pci_probe+0x4a/0x90 [ 1.950670] pci_device_probe+0xff/0x1b0 [ 1.950670] really_probe+0x1cf/0x440 [ 1.950670] ? rdinit_setup+0x31/0x31 [ 1.950670] driver_probe_device+0xe8/0x150 [ 1.950670] device_driver_attach+0x58/0x60 [ 1.950670] __driver_attach+0x8f/0x150 [ 1.950670] ? device_driver_attach+0x60/0x60 [ 1.950670] ? device_driver_attach+0x60/0x60 [ 1.950670] bus_for_each_dev+0x79/0xc0 [ 1.950670] ? kmem_cache_alloc_trace+0x323/0x430 [ 1.950670] driver_attach+0x1e/0x20 [ 1.950670] bus_add_driver+0x154/0x1f0 [ 1.950670] driver_register+0x70/0xc0 [ 1.950670] __pci_register_driver+0x54/0x60 [ 1.950670] idxd_init_module+0xe2/0xfc [ 1.950670] ? idma64_platform_driver_init+0x19/0x19 [ 1.950670] do_one_initcall+0x4a/0x1e0 [ 1.950670] kernel_init_freeable+0x1fc/0x25c [ 1.950670] ? rest_init+0xba/0xba [ 1.950670] kernel_init+0xe/0x116 [ 1.950670] ret_from_fork+0x1f/0x30 [ 1.950670] Modules linked in: [ 1.950670] CR2: 0000000000000060 [ 1.950670] --[ end trace cd7d1b226d3ca901 ]--
Fixes: 7de3697e9cbd ("Add auxiliary bus support") Reported-by: Jacob Pan jacob.jun.pan@intel.com Reviewed-by: Dan Williams dan.j.williams@intel.com Acked-by: Dave Ertman david.m.ertman@intel.com Signed-off-by: Dave Jiang dave.jiang@intel.com Link: https://lore.kernel.org/r/20210210201611.1611074-1-dave.jiang@intel.com Cc: stable stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Yuanzheng Song songyuanzheng@huawei.com Reviewed-by: Kefeng Wangwangkefeng.wang@huawei.com Reviewed-by: Hanjun Guo guohanjun@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- drivers/base/auxiliary.c | 13 +++---------- drivers/base/base.h | 5 +++++ drivers/base/init.c | 1 + 3 files changed, 9 insertions(+), 10 deletions(-)
diff --git a/drivers/base/auxiliary.c b/drivers/base/auxiliary.c index 8336535f1e11..d8b314e7d0fd 100644 --- a/drivers/base/auxiliary.c +++ b/drivers/base/auxiliary.c @@ -15,6 +15,7 @@ #include <linux/pm_runtime.h> #include <linux/string.h> #include <linux/auxiliary_bus.h> +#include "base.h"
static const struct auxiliary_device_id *auxiliary_match_id(const struct auxiliary_device_id *id, const struct auxiliary_device *auxdev) @@ -260,19 +261,11 @@ void auxiliary_driver_unregister(struct auxiliary_driver *auxdrv) } EXPORT_SYMBOL_GPL(auxiliary_driver_unregister);
-static int __init auxiliary_bus_init(void) +void __init auxiliary_bus_init(void) { - return bus_register(&auxiliary_bus_type); + WARN_ON(bus_register(&auxiliary_bus_type)); }
-static void __exit auxiliary_bus_exit(void) -{ - bus_unregister(&auxiliary_bus_type); -} - -module_init(auxiliary_bus_init); -module_exit(auxiliary_bus_exit); - MODULE_LICENSE("GPL v2"); MODULE_DESCRIPTION("Auxiliary Bus"); MODULE_AUTHOR("David Ertman david.m.ertman@intel.com"); diff --git a/drivers/base/base.h b/drivers/base/base.h index 91cfb8405abd..7d97447460fa 100644 --- a/drivers/base/base.h +++ b/drivers/base/base.h @@ -119,6 +119,11 @@ static inline int hypervisor_init(void) { return 0; } extern int platform_bus_init(void); extern void cpu_dev_init(void); extern void container_dev_init(void); +#ifdef CONFIG_AUXILIARY_BUS +extern void auxiliary_bus_init(void); +#else +static inline void auxiliary_bus_init(void) { } +#endif
struct kobject *virtual_device_parent(struct device *dev);
diff --git a/drivers/base/init.c b/drivers/base/init.c index 908e6520e804..a9f57c22fb9e 100644 --- a/drivers/base/init.c +++ b/drivers/base/init.c @@ -32,6 +32,7 @@ void __init driver_init(void) */ of_core_init(); platform_bus_init(); + auxiliary_bus_init(); cpu_dev_init(); memory_dev_init(); container_dev_init();