Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: drm/prime: Fix use after free in mmap with drm_gem_ttm_mmap drm_gem_ttm_mmap() drops a reference to the gem object on success. If the gem object's refcount == 1 on entry to drm_gem_prime_mmap(), that drop will free the gem object, and the subsequent drm_gem_object_get() will be a UAF. Fix by grabbing a reference before calling the mmap helper. This issue was forseen when the reference dropping was adding in commit 9786b65bc61ac ("drm/ttm: fix mmap refcounting"): "For that to work properly the drm_gem_object_get() call in drm_gem_ttm_mmap() must be moved so it happens before calling obj->funcs->mmap(), otherwise the gem refcount would go down to zero."
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 9786b65bc61acec63f923978c75e707afbb74bc7 before 4f8e469a2384dfa4047145b0093126462cbb6dc0; affected 9786b65bc61acec63f923978c75e707afbb74bc7 before 8244a3bc27b3efd057da154b8d7e414670d5044f |
| Linux / Linux | affected 5.5; unaffected 0 before 5.5; unaffected 5.15.5 through 5.15.*; unaffected 5.16 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/4f8e469a2384dfa4047145b0093126462cbb6dc0
- https://git.kernel.org/stable/c/8244a3bc27b3efd057da154b8d7e414670d5044f
ADP enrichment
No English description supplied.
No references supplied.
No English description supplied.