CVE-2026-68445

Summary

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

drm/vc4: Prevent shader BO mappings from becoming writable

vc4_gem_object_mmap() rejects a writable mapping of a validated shader BO, but leaves VM_MAYWRITE set. Userspace can map the BO read-only and then turn it writable with mprotect().

Validated shader BOs must stay read-only: the validator checks the instructions once and the GPU trusts them afterwards. A writable mapping lets userspace rewrite the code after validation, bypassing the validator.

Clear VM_MAYWRITE on the read-only path so the mapping cannot be upgraded, as i915 already does for its read-only objects.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux463873d5701427f2964a0b4b72c45f1f14b6df87 < 9f0ee411fc2d76333d6087c5862ffa907cf7a175affected
LinuxLinux463873d5701427f2964a0b4b72c45f1f14b6df87 < 019e6ad247f7fd038d2e009789f6d9bfcccb1ae7affected
LinuxLinux463873d5701427f2964a0b4b72c45f1f14b6df87 < 6deaa317201851c644c431b57682e54d06b35838affected
LinuxLinux463873d5701427f2964a0b4b72c45f1f14b6df87 < fe168ef1d232d734d9998fd74822e2e20930dfffaffected
LinuxLinux463873d5701427f2964a0b4b72c45f1f14b6df87 < 0c9e6367639548307d3f578f6943ce72c9d39087affected
LinuxLinux4.5affected
LinuxLinux0 < 4.5unaffected
LinuxLinux6.6.148 <= 6.6.*unaffected
LinuxLinux6.12.101 <= 6.12.*unaffected
LinuxLinux6.18.42 <= 6.18.*unaffected
LinuxLinux7.1.6 <= 7.1.*unaffected
LinuxLinux7.2-rc5 <= *unaffected

Weaknesses

References