Overview
About vulnerability
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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , Amazon Linux 2 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Debian 10 ELS , Debian 11 ELS , Oracle Linux 7 ELS , TuxCare 9.6 ESU , TuxCare 9.8 ESU , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS , Ubuntu 20.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+12 more)
Fixes
KernelCare state
Live-patch status from KernelCare for each operating system.
| Operating system | Status | Covered kernels |
|---|---|---|
| Debian 13 | Will Not Fix |
14 kernels
|
| Ubuntu 24.04 | Planned | — |
| Ubuntu 24.04 AWS | Planned | — |
| Ubuntu 26.04 | Will Not Fix | — |