CVE-2026-63880
Description
In the Linux kernel, the following vulnerability has been resolved:
drm/amdgpu: fix lock leak on ENOMEM in AMDGPU_GEM_OP_GET_MAPPING_INFO
The AMDGPU_GEM_OP_GET_MAPPING_INFO branch of amdgpu_gem_op_ioctl()
holds three cleanup-tracked resources before calling kvcalloc():
the drm_gem_object reference from drm_gem_object_lookup(), the
drm_exec lock on the looked-up GEM via drm_exec_lock_obj(), and
the drm_exec lock on the per-process VM root page directory via
amdgpu_vm_lock_pd(). All three are released by the out_exec
label that every other error path in this function jumps to.
The kvcalloc() failure path returns -ENOMEM directly, skipping
out_exec and leaking all three.
The leaked per-process VM root PD dma_resv lock is the
load-bearing leak: any subsequent operation on the same VM
(further GEM ops, command-submission, eviction, TTM shrinker
callbacks) blocks on the held lock. DRM_IOCTL_AMDGPU_GEM_OP is
DRM_AUTH | DRM_RENDER_ALLOW, so this is an unprivileged-local
denial of service against the caller's GPU context, reachable
by any process with /dev/dri/renderD* access.
Route the failure through out_exec so drm_exec_fini() and
drm_gem_object_put() run.
Reproduced on stock 7.0.0-10, Ryzen 7 5700U / Radeon Vega
(Lucienne): the failing ioctl returns -ENOMEM and a second
GET_MAPPING_INFO on the same fd then blocks in
drm_exec_lock_obj() on the leaked dma_resv. SIGKILL on the
caller does not reap the task; the fd-release path during
process exit goes through amdgpu_gem_object_close() ->
drm_exec_prepare_obj() on the same lock, leaving the task in D
state until the box is rebooted. The patched kernel was not
rebuilt and re-tested on this hardware; the fix is mechanical.
Tested on a single Lucienne / Vega box only.
Ziyi Guo posted an independent INT_MAX-bound check for
args->num_entries in the same branch [1]; the two patches are
complementary and can land in either order.
(cherry picked from commit b69d3256d79de15f54c322986ff4da68f1d65b0a)
Metadata
Severity & Metrics
No CVSS data available.
Affected products (2)
| Vendor | Product | Platform | Versions |
|---|---|---|---|
| Linux | Linux | — | 4d82724f7f2b847eb0454b1aab5450545b39abd4 < 1eb86334e391695d4a40743b114afc15df4dc506, 4d82724f7f2b847eb0454b1aab5450545b39abd4 < 8f643d534ffc6f1b6182e4f3acff8f04890504b9, 4d82724f7f2b847eb0454b1aab5450545b39abd4 < 2e7f55eb408c3f72ee1957a0d0ad11d8648a6379 |
| Linux | Linux | — | 6.18, 0 < 6.18, 6.18.35 ≤ 6.18.*, 7.0.12 ≤ 7.0.* … |
References (3)