CVE-2026-97900
Received
Received - Intake
Linux Kernel drm_exec Contention Handling Flaw
Vulnerability report for CVE-2026-97900, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-09-25
Last updated on: 2026-09-25
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
drm/drm_exec: fix up contended obj when num_objects is 0
drm_exec_prepare_array() silently returns success without calling
drm_exec_lock_contended() when num_objects is zero. This breaks the
invariant upheld by drm_exec_lock_obj(), where every entry point into
the locking sequence must first attempt to lock any previously
contended object before proceeding.
Drivers that chain multiple drm_exec_prepare_array() calls per
drm_exec_until_all_locked() iteration (e.g. amdgpu's userq signal/wait
ioctls, which prepare separate read and write BO arrays) can pass an
empty array for one of the two calls. If contention is hit while
preparing the non-empty array, exec->contended is set and the loop
retries; on retry, the empty-array call preceding it is a no-op that
never clears exec->contended, so drm_exec_retry_on_contention()
immediately jumps back to the top of the loop without ever reaching
the call that would resolve the contention. This spins forever.
Fix it by having drm_exec_prepare_array() call drm_exec_lock_contended()
directly when num_objects is zero, so a pending contended object dont
loop infinitely.
CVSS Scores
EPSS Scores
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |