Bug 2559546 (CVE-2026-98894)

Summary: CVE-2026-98894 kernel: drm/amd/ras: reset CPER ring on corrupt entry size
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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A flaw was found in the AMD GPU driver within the Linux kernel. When handling overflow conditions in the Common Platform Error Record (CPER) ring buffer, the driver relies on parsed entry sizes from the buffer contents without verifying that the read pointer advances. Corrupt error record data can cause the recovery loop to repeat indefinitely while holding a ring lock. This issue can cause kernel worker threads to hang, resulting in a denial of service.
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Description OSIDB Bzimport 2026-10-23 11:52:23 UTC 
In the Linux kernel, the following vulnerability has been resolved:

drm/amd/ras: reset CPER ring on corrupt entry size

When CPER ring overflow handling advances the read pointer, it trusts the
parsed entry size from the current ring contents. Corrupt CPER data can
produce an entry size that does not advance rptr after dword conversion
and pointer masking.

In that case the recovery loop keeps testing the same location while
holding the CPER ring mutex. This can hang the worker that is writing the
next CPER record.

Detect a no-progress rptr update and reset the CPER ring to an empty
state instead. This drops the corrupt contents and lets the writer leave
the recovery path without spinning.
Comment 1 Mauro Matteo Cascella 2026-10-26 14:28:18 UTC 
Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98894.mbox