Bug 2492365 (CVE-2026-52987)

Summary: CVE-2026-52987 kernel: drm/amdgpu: avoid double drm_exec_fini() in userq validate
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: high    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel. A double free vulnerability exists in the `drm/amdgpu` component within the `userq validate` function. This issue arises because the `drm_exec_fini()` function is called twice on the same execution object, which is not designed to be idempotent. An attacker could potentially exploit this to cause a denial of service or lead to unpredictable system behavior.
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Description OSIDB Bzimport 2026-06-24 18:08:05 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: avoid double drm_exec_fini() in userq validate

When new_addition is true, amdgpu_userq_vm_validate() calls
drm_exec_fini(&exec) before iterating over the collected HMM ranges and
calling amdgpu_ttm_tt_get_user_pages().

If amdgpu_ttm_tt_get_user_pages() fails in that path, the code jumps to
unlock_all and calls drm_exec_fini(&exec) a second time on the same
exec object. drm_exec_fini() is not idempotent: it frees exec->objects
and may also drop exec->contended and finalize the ww acquire context.

Route that error path directly to the range cleanup once exec has
already been finalized.

Issue found using a prototype static analysis tool
and confirmed by code review.

(cherry picked from commit 2802952e4a07306da6ebe813ff1acacc5691851a)
Comment 1 Keith Grant 2026-06-26 20:07:11 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062443-CVE-2026-52987-29bd@gregkh/T