CVE-2024-50030

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

drm/xe/ct: prevent UAF in send_recv()

Ensure we serialize with completion side to prevent UAF with fence going out of scope on the stack, since we have no clue if it will fire after the timeout before we can erase from the xa. Also we have some dependent loads and stores for which we need the correct ordering, and we lack the needed barriers. Fix this by grabbing the ct->lock after the wait, which is also held by the completion side.

v2 (Badal):

• Also print done after acquiring the lock and seeing timeout.

(cherry picked from commit 52789ce35c55ccd30c4b67b9cc5b2af55e0122ea)

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.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/8ed7dd4c55e4fb21531a9645aeb66a30eaf43a46
• https://git.kernel.org/stable/c/db7f92af626178ba59dbbcdd5dee9ec24a987a88