drm/xe: Add bounds check on pat_index to prevent OOB kernel read in madvise

Summary

In the Linux kernel, the following vulnerability has been resolved: drm/xe: Add bounds check on pat_index to prevent OOB kernel read in madvise When user provides a bogus pat_index value through the madvise IOCTL, the xe_pat_index_get_coh_mode() function performs an array access without validating bounds. This allows a malicious user to trigger an out-of-bounds kernel read from the xe->pat.table array. The vulnerability exists because the validation in madvise_args_are_sane() directly calls xe_pat_index_get_coh_mode(xe, args->pat_index.val) without first checking if pat_index is within [0, xe->pat.n_entries). Although xe_pat_index_get_coh_mode() has a WARN_ON to catch this in debug builds, it still performs the unsafe array access in production kernels. v2(Matthew Auld) • Using array_index_nospec() to mitigate spectre attacks when the value is used v3(Matthew Auld) • Put the declarations at the start of the block (cherry picked from commit 944a3329b05510d55c69c2ef455136e2fc02de29)

Timeline

1. May 6, 2026, 11:29 AM UTCCVE published
2. Oct 16, 2026, 3:16 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. Oct 19, 2026, 7:16 PM UTCRecord last updated

Affected versions

• Linux Linux

  From ada7486c5668db542a7d361268df931aca5b726a · fixed in ffba51100ff61792fefbae11ca38ac1987a818dd; From ada7486c5668db542a7d361268df931aca5b726a · fixed in 79f52655567a6471ff3d0d6325ede91bb14461f4; From ada7486c5668db542a7d361268df931aca5b726a · fixed in fbbe32618e97eff81577a01eb7d9adcd64a216d7

• Linux Linux

  6.18

• KernelLinux

  From 6.18.0 · fixed in 6.18.16; From 6.19.0 · fixed in 6.19.6

References 3