CVE-2022-49359

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

drm/panfrost: Job should reference MMU not file_priv

For a while now its been allowed for a MMU context to outlive its corresponding panfrost_priv, however the job structure still references panfrost_priv to get hold of the MMU context. If panfrost_priv has been freed this is a use-after-free which Ive been able to trigger resulting in a splat.

To fix this, drop the reference to panfrost_priv in the job structure and add a direct reference to the MMU structure which is whats actually needed.

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/472dd7ea5e19a1aeabf1711ddc756777e05ee7c2
• https://git.kernel.org/stable/c/6e516faf04317db2c46cbec4e3b78b4653a5b109
• https://git.kernel.org/stable/c/8c8e8cc91a6ffc79865108279a74fd57d9070a17