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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
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Wed, 12 Aug 2026 17:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-265 CWE-284 |
Wed, 12 Aug 2026 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | 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. | |
| Title | drm/vc4: Prevent shader BO mappings from becoming writable | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-12T00:07:36.230Z
Reserved: 2026-07-30T09:28:09.394Z
Link: CVE-2026-68445
No data.
Status : Received
Published: 2026-08-12T00:17:44.860
Modified: 2026-08-12T00:17:44.860
Link: CVE-2026-68445
No data.
OpenCVE Enrichment
Updated: 2026-08-12T17:45:02Z