Bug 2492274 (CVE-2026-52966)

Summary: CVE-2026-52966 kernel: drm: Replace old pointer to new idr
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the Linux kernel's Direct Rendering Manager (DRM) subsystem. A logical error in the 'change handle' logic, specifically related to the replacement of IDR (ID allocator) pointers, could lead to a kernel warning or system panic. This issue could allow a local attacker to trigger a system crash, resulting in a denial of service.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-06-24 18:02:18 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm: Replace old pointer to new idr

Commit 5e28b7b94408 introduced a logical error by failing to replace the
newly generated IDR pointer to old id's pointer at the correct location
within the "change handle" logic; this resulted in the issue reported by
syzbot [1].

Specifically, the new IDR object pointer is intended to replace the original
id's pointer during the normal execution flow.

Additionally, an unnecessary conditional check for the ret exit path has
been removed.

[1]
!RB_EMPTY_ROOT(&prime_fpriv->dmabufs)
WARNING: drivers/gpu/drm/drm_prime.c:224 at drm_prime_destroy_file_private+0x48/0x60 drivers/gpu/drm/drm_prime.c:224, CPU#0: syz.0.17/5833
Call Trace:
 drm_file_free.part.0+0x7e6/0xcc0 drivers/gpu/drm/drm_file.c:269
 drm_file_free drivers/gpu/drm/drm_file.c:237 [inline]
 drm_close_helper.isra.0+0x186/0x200 drivers/gpu/drm/drm_file.c:290
 drm_release+0x1ab/0x360 drivers/gpu/drm/drm_file.c:438
Comment 1 Mauro Matteo Cascella 2026-06-25 14:09:14 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026062438-CVE-2026-52966-2a66@gregkh/T