CVE-2026-53138 PUBLISHED

drm/amd/display: Bound VBIOS record-chain walk loops

Assigner: Linux
Reserved: 09.06.2026 Published: 25.06.2026 Updated: 25.06.2026

In the Linux kernel, the following vulnerability has been resolved:

drm/amd/display: Bound VBIOS record-chain walk loops

[Why & How] All record-chain walk loops in bios_parser.c and bios_parser2.c use for(;;) and only terminate on a 0xFF record_type sentinel or zero record_size. A malformed VBIOS image missing the terminator record causes unbounded iteration at probe time, potentially hundreds of thousands of iterations with record_size=1. In the final iterations near the BIOS image boundary, struct casts beyond the 2-byte header validated by GET_IMAGE can also read out of bounds.

Cap all 14 record-chain walk loops to BIOS_MAX_NUM_RECORD (256) iterations. The atombios.h defines up to 22 distinct record types and atomfirmware.h has 13. Assuming an average of less than 10 records per type (which is reasonable since most are connector- based) 256 is a generous upper bound.

(cherry picked from commit 95700a3d660287ed657d6892f7be9ffc0e294a93)

Product Status

Vendor Linux
Product Linux
Versions Default: unaffected
  • affected from 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c to 6173cfea2f916e01c4f98e29cd654384a05e32a3 (excl.)
  • affected from 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c to 0e56f460bddb397fa9a8e6faf7ae7eaa86953eb1 (excl.)
  • affected from 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c to 2645e3caf7e013189da9c6ff621d006cca5a538b (excl.)
  • affected from 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c to ff287df16a1a58aca78b08d1f3ee09fc44da0351 (excl.)
Vendor Linux
Product Linux
Versions Default: affected
  • Version 4.15 is affected
  • unaffected from 0 to 4.15 (excl.)
  • unaffected from 6.12.94 to 6.12.* (incl.)
  • unaffected from 6.18.36 to 6.18.* (incl.)
  • unaffected from 7.0.13 to 7.0.* (incl.)
  • unaffected from 7.1 to * (incl.)

References