In the Linux kernel, the following vulnerability has been resolved: ublk: detach gendisk from ublk device if add_disk() fails Inside ublk_abort_requests(), gendisk is grabbed for aborting all inflight requests. And ublk_abort_requests() is called when exiting the uring context or handling timeout. If add_disk() fails, the gendisk may have been freed when calling ublk_abort_requests(), so use-after-free can be caused when getting disk's reference in ublk_abort_requests(). Fixes the bug by detaching gendisk from ublk device if add_disk() fails.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.