Bug 2463258 (CVE-2026-31690)

Summary: CVE-2026-31690 kernel: firmware: thead: Fix buffer overflow and use standard endian macros
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: unspecified Docs Contact:
Priority: unspecified    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel's TH1520 AON firmware protocol driver. This buffer overflow vulnerability arises from unsafe pointer arithmetic used to access the 'mode' field through the 'resource' pointer with an offset. This could potentially lead to memory corruption within the kernel.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-04-27 18:23:21 UTC 
In the Linux kernel, the following vulnerability has been resolved:

firmware: thead: Fix buffer overflow and use standard endian macros

Addresses two issues in the TH1520 AON firmware protocol driver:

1. Fix a potential buffer overflow where the code used unsafe pointer
   arithmetic to access the 'mode' field through the 'resource' pointer
   with an offset. This was flagged by Smatch static checker as:
   "buffer overflow 'data' 2 <= 3"

2. Replace custom RPC_SET_BE* and RPC_GET_BE* macros with standard
   kernel endianness conversion macros (cpu_to_be16, etc.) for better
   portability and maintainability.

The functionality was re-tested with the GPU power-up sequence,
confirming the GPU powers up correctly and the driver probes
successfully.

[   12.702370] powervr ffef400000.gpu: [drm] loaded firmware
powervr/rogue_36.52.104.182_v1.fw
[   12.711043] powervr ffef400000.gpu: [drm] FW version v1.0 (build
6645434 OS)
[   12.719787] [drm] Initialized powervr 1.0.0 for ffef400000.gpu on
minor 0
Comment 1 Keith Grant 2026-04-27 22:21:33 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042757-CVE-2026-31690-018e@gregkh/T