CVE-2026-53138
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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)
- CVSS 3.1
- 7.1 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-125
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/04e271a952b8863bbafc99bd51aca4c32bff0e0dPatch
- https://git.kernel.org/stable/c/0e56f460bddb397fa9a8e6faf7ae7eaa86953eb1Patch
- https://git.kernel.org/stable/c/2645e3caf7e013189da9c6ff621d006cca5a538bPatch
- https://git.kernel.org/stable/c/499c6b43a79dd684bddbd18fe8b2235aa2764db4Patch
- https://git.kernel.org/stable/c/6173cfea2f916e01c4f98e29cd654384a05e32a3Patch
- https://git.kernel.org/stable/c/6723188c42ca3b34a9fce634d7a0ecc9ccd5cd56Patch
- https://git.kernel.org/stable/c/e94f5323c41f32a74160378c3b19850d1f203ad5Patch
- https://git.kernel.org/stable/c/ff287df16a1a58aca78b08d1f3ee09fc44da0351Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.