6.7-stable review patch. If anyone has any objections, please let me know.
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From: Fenghua Yu fenghua.yu@intel.com
[ Upstream commit d3ea125df37dc37972d581b74a5d3785c3f283ab ]
If CONFIG_HARDENED_USERCOPY is enabled, copying completion record from event log cache to user triggers a kernel bug.
[ 1987.159822] usercopy: Kernel memory exposure attempt detected from SLUB object 'dsa0' (offset 74, size 31)! [ 1987.170845] ------------[ cut here ]------------ [ 1987.176086] kernel BUG at mm/usercopy.c:102! [ 1987.180946] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 1987.186866] CPU: 17 PID: 528 Comm: kworker/17:1 Not tainted 6.8.0-rc2+ #5 [ 1987.194537] Hardware name: Intel Corporation AvenueCity/AvenueCity, BIOS BHSDCRB1.86B.2492.D03.2307181620 07/18/2023 [ 1987.206405] Workqueue: wq0.0 idxd_evl_fault_work [idxd] [ 1987.212338] RIP: 0010:usercopy_abort+0x72/0x90 [ 1987.217381] Code: 58 65 9c 50 48 c7 c2 17 85 61 9c 57 48 c7 c7 98 fd 6b 9c 48 0f 44 d6 48 c7 c6 b3 08 62 9c 4c 89 d1 49 0f 44 f3 e8 1e 2e d5 ff <0f> 0b 49 c7 c1 9e 42 61 9c 4c 89 cf 4d 89 c8 eb a9 66 66 2e 0f 1f [ 1987.238505] RSP: 0018:ff62f5cf20607d60 EFLAGS: 00010246 [ 1987.244423] RAX: 000000000000005f RBX: 000000000000001f RCX: 0000000000000000 [ 1987.252480] RDX: 0000000000000000 RSI: ffffffff9c61429e RDI: 00000000ffffffff [ 1987.260538] RBP: ff62f5cf20607d78 R08: ff2a6a89ef3fffe8 R09: 00000000fffeffff [ 1987.268595] R10: ff2a6a89eed00000 R11: 0000000000000003 R12: ff2a66934849c89a [ 1987.276652] R13: 0000000000000001 R14: ff2a66934849c8b9 R15: ff2a66934849c899 [ 1987.284710] FS: 0000000000000000(0000) GS:ff2a66b22fe40000(0000) knlGS:0000000000000000 [ 1987.293850] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 1987.300355] CR2: 00007fe291a37000 CR3: 000000010fbd4005 CR4: 0000000000f71ef0 [ 1987.308413] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 1987.316470] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400 [ 1987.324527] PKRU: 55555554 [ 1987.327622] Call Trace: [ 1987.330424] <TASK> [ 1987.332826] ? show_regs+0x6e/0x80 [ 1987.336703] ? die+0x3c/0xa0 [ 1987.339988] ? do_trap+0xd4/0xf0 [ 1987.343662] ? do_error_trap+0x75/0xa0 [ 1987.347922] ? usercopy_abort+0x72/0x90 [ 1987.352277] ? exc_invalid_op+0x57/0x80 [ 1987.356634] ? usercopy_abort+0x72/0x90 [ 1987.360988] ? asm_exc_invalid_op+0x1f/0x30 [ 1987.365734] ? usercopy_abort+0x72/0x90 [ 1987.370088] __check_heap_object+0xb7/0xd0 [ 1987.374739] __check_object_size+0x175/0x2d0 [ 1987.379588] idxd_copy_cr+0xa9/0x130 [idxd] [ 1987.384341] idxd_evl_fault_work+0x127/0x390 [idxd] [ 1987.389878] process_one_work+0x13e/0x300 [ 1987.394435] ? __pfx_worker_thread+0x10/0x10 [ 1987.399284] worker_thread+0x2f7/0x420 [ 1987.403544] ? _raw_spin_unlock_irqrestore+0x2b/0x50 [ 1987.409171] ? __pfx_worker_thread+0x10/0x10 [ 1987.414019] kthread+0x107/0x140 [ 1987.417693] ? __pfx_kthread+0x10/0x10 [ 1987.421954] ret_from_fork+0x3d/0x60 [ 1987.426019] ? __pfx_kthread+0x10/0x10 [ 1987.430281] ret_from_fork_asm+0x1b/0x30 [ 1987.434744] </TASK>
The issue arises because event log cache is created using kmem_cache_create() which is not suitable for user copy.
Fix the issue by creating event log cache with kmem_cache_create_usercopy(), ensuring safe user copy.
Fixes: c2f156bf168f ("dmaengine: idxd: create kmem cache for event log fault items") Reported-by: Tony Zhu tony.zhu@intel.com Tested-by: Tony Zhu tony.zhu@intel.com Signed-off-by: Fenghua Yu fenghua.yu@intel.com Reviewed-by: Lijun Pan lijun.pan@intel.com Reviewed-by: Dave Jiang dave.jiang@intel.com Link: https://lore.kernel.org/r/20240209191412.1050270-1-fenghua.yu@intel.com Signed-off-by: Vinod Koul vkoul@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/dma/idxd/init.c | 15 ++++++++++++--- 1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c index 0eb1c827a215f..d09a8553ea71d 100644 --- a/drivers/dma/idxd/init.c +++ b/drivers/dma/idxd/init.c @@ -342,7 +342,9 @@ static void idxd_cleanup_internals(struct idxd_device *idxd) static int idxd_init_evl(struct idxd_device *idxd) { struct device *dev = &idxd->pdev->dev; + unsigned int evl_cache_size; struct idxd_evl *evl; + const char *idxd_name;
if (idxd->hw.gen_cap.evl_support == 0) return 0; @@ -354,9 +356,16 @@ static int idxd_init_evl(struct idxd_device *idxd) spin_lock_init(&evl->lock); evl->size = IDXD_EVL_SIZE_MIN;
- idxd->evl_cache = kmem_cache_create(dev_name(idxd_confdev(idxd)), - sizeof(struct idxd_evl_fault) + evl_ent_size(idxd), - 0, 0, NULL); + idxd_name = dev_name(idxd_confdev(idxd)); + evl_cache_size = sizeof(struct idxd_evl_fault) + evl_ent_size(idxd); + /* + * Since completion record in evl_cache will be copied to user + * when handling completion record page fault, need to create + * the cache suitable for user copy. + */ + idxd->evl_cache = kmem_cache_create_usercopy(idxd_name, evl_cache_size, + 0, 0, 0, evl_cache_size, + NULL); if (!idxd->evl_cache) { kfree(evl); return -ENOMEM;