CVE-2024-46683— drm/xe: prevent UAF around preempt fence

drm/xe: prevent UAF around preempt fence

In the Linux kernel, the following vulnerability has been resolved: drm/xe: prevent UAF around preempt fence The fence lock is part of the queue, therefore in the current design anything locking the fence should then also hold a ref to the queue to prevent the queue from being freed. However, currently it looks like we signal the fence and then drop the queue ref, but if something is waiting on the fence, the waiter is kicked to wake up at some later point, where upon waking up it first grabs the lock before checking the fence state. But if we have already dropped the queue ref, then the lock might already be freed as part of the queue, leading to uaf. To prevent this, move the fence lock into the fence itself so we don't run into lifetime issues. Alternative might be to have device level lock, or only release the queue in the fence release callback, however that might require pushing to another worker to avoid locking issues. References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2454 References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2342 References: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/2020 (cherry picked from commit 7116c35aacedc38be6d15bd21b2fc936eed0008b)

N/A

N/A

Linux kernel 资源管理错误漏洞

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在资源管理错误漏洞，该漏洞源于在处理预占用栅栏时未能正确管理内存引用计数，可能导致内存释放后重用问题。

N/A

N/A