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CVE-2026-74357
drm/amdgpu: fix KASAN slab-out-of-bounds in amdgpu_coredump ring dump
Published 2026-08-15 (2 months ago) by the Linux kernel CNA. Subsystem drivers/gpu. Debian urgency: unimportant.
What to do, per Debian release
Debian's own status for CVE-2026-74357 in every release this site tracks, and what each one means in practice. Every status below is the one the Debian Security Team publishes for this CVE. source
| Release | Status | Version | What this means |
|---|---|---|---|
| Debian 12bookworm | not affected | 6.1.190-1 | Nothing to do. bookworm never shipped the vulnerable code. |
| Debian 13trixie | not affected | 6.12.113-1 | Nothing to do. trixie never shipped the vulnerable code. |
| Debian 14forky | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
| Debian unstablesid | fixed | 7.1.5-1 | Update the kernel and reboot. Fixed in 7.1.5-1. A running kernel keeps the old code until the machine restarts. |
The vulnerability
What the bug is
The ring content dump in amdgpu_coredump() uses two separate loops over adev->rings[]: the first counts rings with unsignalled fences to size the allocation, and the second copies ring data into the allocated buffers. Both loops use the same condition to skip rings: atomic_read(&ring->fence_drv.last_seq) == ring->fence_drv.sync_seq Because last_seq is an atomic that is updated concurrently by the fence signalling path, additional rings may appear unsignalled in the second loop that were signalled during the first. When this happens, idx exceeds the allocated ring_count and the store to coredump->rings[idx] writes past the end of the kcalloc-ed buffer. This was found during IGT stressful test amd_queue_reset which triggers random GPU resets. The OVERSIZE subtest (CMD_STREAM_EXEC_INVALID_PACKET_LENGTH_OVERSIZE on GFX ring) provokes a ring timeout and subsequent coredump, which hits the race between the counting and copying loops. The failure is non-deterministic and depends on fence signalling timing during the reset. KASAN log: BUG: KASAN: slab-out-of-bounds in amdgpu_coredump+0x1274/0x12f0 [amdgpu] Write of size 4 at addr ffff888106154258 by task kworker/u128:5/23625 CPU: 16 UID: 0 PID: 23625 Comm: kworker/u128:5 Not tainted 6.19.0+ #35 Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched] Call Trace: <TASK> dump_stack_lvl+0xa5/0x110 print_report+0xd1/0x660 kasan_report+0xf3/0x130 __asan_report_store4_noabort+0x17/0x30 amdgpu_coredump+0x1274/0x12f0 [amdgpu] amdgpu_job_timedout+0xef0/0x16c0 [amdgpu] drm_sched_job_timedout+0x194/0x5c0 [gpu_sched] process_one_work+0x84b/0x1990 worker_thread+0x6b8/0x11b0 </TASK> Allocated by task 23625: kasan_save_stack+0x39/0x70 __kasan_kmalloc+0xc3/0xd0 __kmalloc_noprof+0x2ec/0x910 amdgpu_coredump+0x5c5/0x12f0 [amdgpu] amdgpu_job_timedout+0xef0/0x16c0 [amdgpu] The buggy address belongs to the object at ffff888106154200 which belongs to the cache kmalloc-rnd-09-96 of size 96 The buggy address is located 16 bytes to the right of allocated 72-byte region [ffff888106154200, ffff888106154248) 72 bytes = 3 * sizeof(struct amdgpu_coredump_ring), so ring_count was 3 but idx reached 3+, writing ring_index (at struct offset 16) 16 bytes past the allocation. Fix by adding an idx < ring_count guard to the copy loop so it cannot exceed the allocated count even when the fence state changes between the two passes.
Where it lives
The fix touches these files. If the subsystem is one you do not use, the practical exposure is lower, though the package is still the vulnerable one.
drivers/gpu/drm/amd/amdgpu/amdgpu_dev_coredump.c
- What this is
- RADEON and AMDGPU DRM DRIVERSMAINTAINERS section matched on drivers/gpu/drm/amd/ · amd-gfx@lists.freedesktop.org · Supported
- Kernel module
- amdgpu
Check it on the machine
grep -w CONFIG_DRM_AMDGPU /boot/config-$(uname -r)Reads the booted kernel's own configuration, on the machine and nowhere else. =y is built in, =m is a module, and an is not set line means the code is not there.
lsmod | grep -w amdgpuPrints a line if that module is loaded right now, and nothing if it is not. One that is not loaded can still be loaded later by anything that needs it.
Show whether Debian builds this, per release
Debian builds this, but not on every flavour. At least one release below builds the code on some of its kernel flavours and not on others, so the answer depends on the architecture and flavour installed. The build rule could not be established for 1 release, so nothing is claimed about those.
- bookworm?
- trixieMnot built on amd64/cloud-amd64, arm64/cloud-arm64, armel/rpi, armhf/armmp, armhf/armmp-lpae, armhf/rt/armmp, s390x/s390x
- forky, sidMnot built on amd64/cloud-amd64, arm64/cloud-arm64, s390x/s390x
- ?
- not established - no Makefile entry for the affected file
- M
- a module where it is built at all; some flavours do not build it
Where a release above reads "not established", no build rule for the affected file was found in that release's kernel tree. That is a gap in this lookup, not a finding that the code is absent.
- Build switch
- CONFIG_DRM_AMDGPU
From the configuration Debian publishes for every kernel flavour it builds. It covers only the architectures Debian ships a linux-config package for, and nothing about a kernel you built yourself. Debian's own status above stays authoritative about the source package.MAINTAINERS kbuild Makefiles Debian linux-config packages
Signals
- Published
- 2026-08-15 (2 months ago)source
- CVSS
- 7.8 high
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsource recompute it - Attack vector
- local (AV:L)source
- EPSS
- 0.17%, higher than 5.3% of all CVEssource
- CISA KEV
- not listedthe KEV catalogue
- Debian urgency
- unimportantsource
- Subsystem
- drivers/gpu
Upstream fixes
The versions the CNA records as introducing and fixing this, and the commit for each. source
| Introduced | Fixed in | Commit |
|---|---|---|
| 7.1 | 7.1.5 | efb1dadaeb89 |
| 7.1 | 7.2 | 08ac3a7879d3 |
Why the CNA scored it this way
Quoted from the kernel CNA's own scoring file, word for word. A highlighted metric carries the most severe value CVSS v3.1 defines for it, which is what pushes the score up. source
- AV:LAttack vector, local
- Exploitation requires submitting AMDGPU_CS ioctls on /dev/dri/renderD* to hang a GPU ring, which triggers amdgpu_coredump() from the local drm_sched_job_timedout workqueue during reset recovery.
- AC:LAttack complexity, low
- An attacker can reliably provoke ring timeouts with crafted GFX packets (e.g., invalid packet length oversize per IGT) and repeatedly retry to win the fence-signalling race between the counting and copy loops.
- PR:LPrivileges required, low
- AMDGPU_CS and related ioctls are allowed for DRM render clients on /dev/dri/renderD*, reachable by unprivileged local users in the render/video group on workstations, gaming PCs, and cloud GPU tenants.
- UI:NUser interaction, none
- No victim interaction is required; the attacker alone submits malicious GPU command streams that cause the timeout and subsequent vulnerable coredump path.
- S:UScope, unchanged
- The slab-out-of-bounds write corrupts kernel heap memory within the same kernel security authority and does not cross a VM, container, or IOMMU boundary by itself.
- C:HConfidentiality impact, high
- The bug performs out-of-bounds writes past the kcalloc'd rings[] array and can also memcpy past the undersized rings_dw buffer, corrupting adjacent kmalloc objects and enabling kernel memory disclosure.
- I:HIntegrity impact, high
- Out-of-bounds heap writes of ring metadata and full ring buffer contents provide memory corruption primitives that can be leveraged for arbitrary kernel data modification and code execution.
- A:HAvailability impact, high
- Slab-out-of-bounds corruption during GPU reset coredump in a kernel worker can cause kernel Oops/panic or failed recovery, denying availability on AMD GPU systems.