High [CVE-2026-63885] fix race between change_handle and handle_delete
This high-severity Red Hat Linux advisory covers CVE-2026-63885 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7.
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Summary
In the Linux kernel, the following vulnerability has been resolved: drm/gem: fix race between change_handle and handle_delete drm_gem_change_handle_ioctl leaves the old handle live in the IDR during the window between spin_unlock(table_lock) and the final spin_lock(table_lock).
A concurrent drm_gem_handle_delete on the old handle succeeds in this window, decrements handle_count to 0, and frees the GEM object while the new handle's IDR entry still references it. NULL the old handle's IDR entry before dropping table_lock so that any concurrent GEM_CLOSE on the old handle sees NULL and returns -EINVAL.
Restore the old entry on the prime-bookkeeping error path. A flaw was found in the Linux kernel's Direct Rendering Manager (DRM) Graphics Execution Manager (GEM) component.
A race condition, a situation where multiple operations occur in an unpredictable order, exists between the `change_handle` and `handle_delete` operations. This can allow a local attacker to free a Graphics Execution Manager (GEM) object while it is still being referenced by another handle.
This could lead to a use-after-free vulnerability, potentially resulting in a denial of service or other impacts. Red Hat severity: Moderate — CVSS 7 (CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H).
Weakness: CWE-366.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 6 days ago·verify at source
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