drm/drm_exec: fix up contended obj when num_objects is 0
Summary
| CVE | CVE-2026-97900 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 11:17:16 UTC |
| Updated | 2026-10-19 10:17:40 UTC |
| 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. |
Risk And Classification
EPSS: 0.001680000 probability, percentile 0.054500000 (date 2026-10-05)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 09593216bff15866f95c8ad406cb7fdcec1ee40a 506cfed91e50cc8055799480a2fde5a18f63a21c git | Not specified |
| CNA | Linux | Linux | affected 09593216bff15866f95c8ad406cb7fdcec1ee40a 831cd124ce99c3e61266bed30519d52f7c26abed git | Not specified |
| CNA | Linux | Linux | affected 09593216bff15866f95c8ad406cb7fdcec1ee40a f3e74866018dab793ebee1fdf0ef34f7271d1f8c git | Not specified |
| CNA | Linux | Linux | affected 09593216bff15866f95c8ad406cb7fdcec1ee40a a565022c02f218ec9789c2baf4690792e7a48cbb git | Not specified |
| CNA | Linux | Linux | affected 09593216bff15866f95c8ad406cb7fdcec1ee40a 159720704d9d652b64390c11fb971e15b0a78d23 git | Not specified |
| CNA | Linux | Linux | affected 6.6 | Not specified |
| CNA | Linux | Linux | unaffected 6.6 semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.158 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.111 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.53 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2.7 7.2.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.3 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/159720704d9d652b64390c11fb971e15b0a78d23 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/f3e74866018dab793ebee1fdf0ef34f7271d1f8c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/506cfed91e50cc8055799480a2fde5a18f63a21c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/831cd124ce99c3e61266bed30519d52f7c26abed | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/a565022c02f218ec9789c2baf4690792e7a48cbb | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.