CVE-2024-26746

dmaengine: idxd: Ensure safe user copy of completion record

Description

In the Linux kernel, the following vulnerability has been resolved: dmaengine: idxd: Ensure safe user copy of completion record 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.

5.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.01%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Link Tags
https://git.kernel.org/stable/c/5e3022ea42e490a36ec6f2cfa6fc603deb0bace4 patch
https://git.kernel.org/stable/c/bb71e040323175e18c233a9afef32ba14fa64eb7 patch
https://git.kernel.org/stable/c/d3ea125df37dc37972d581b74a5d3785c3f283ab patch

Frequently Asked Questions

What is the severity of CVE-2024-26746?
CVE-2024-26746 has been scored as a medium severity vulnerability.
How to fix CVE-2024-26746?
To fix CVE-2024-26746, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2024-26746 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2024-26746 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-26746?
CVE-2024-26746 affects Linux Linux, Linux Linux.
This platform uses data from the NIST NVD, MITRE CVE, MITRE CWE, First.org and CISA KEV but is not endorsed or certified by these entities. CVE is a registred trademark of the MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. CWE is a registred trademark of the MITRE Corporation and the authoritative source of CWE content is MITRE's CWE web site.
© 2025 Under My Watch. All Rights Reserved.