Description
In the Linux kernel, the following vulnerability has been resolved: drm/i915: Unlink NV12 planes earlier unlink_nv12_plane() will clobber parts of the plane state potentially already set up by plane_atomic_check(), so we must make sure not to call the two in the wrong order. The problem happens when a plane previously selected as a Y plane is now configured as a normal plane by user space. plane_atomic_check() will first compute the proper plane state based on the userspace request, and unlink_nv12_plane() later clears some of the state. This used to work on account of unlink_nv12_plane() skipping the state clearing based on the plane visibility. But I removed that check, thinking it was an impossible situation. Now when that situation happens unlink_nv12_plane() will just WARN and proceed to clobber the state. Rather than reverting to the old way of doing things, I think it's more clear if we unlink the NV12 planes before we even compute the new plane state. (cherry picked from commit 017ecd04985573eeeb0745fa2c23896fb22ee0cc)
Product status
6a01df2f1b2a3b29721143729a3feff816bc0083 (git) before 70e2eb91cb6310a3508439f6f2539dfffa0abf77
6a01df2f1b2a3b29721143729a3feff816bc0083 (git) before 12f3b6cbab8fbeb95097685b40f0147406cf9746
6a01df2f1b2a3b29721143729a3feff816bc0083 (git) before bfa71b7a9dc6b5b8af157686e03308291141d00c
6.15
Any version before 6.15
6.18.21 (semver)
6.19.11 (semver)
7.0 (original_commit_for_fix)
References
git.kernel.org/...c/70e2eb91cb6310a3508439f6f2539dfffa0abf77
git.kernel.org/...c/12f3b6cbab8fbeb95097685b40f0147406cf9746
git.kernel.org/...c/bfa71b7a9dc6b5b8af157686e03308291141d00c