Description
Use After Free vulnerability in Linux Kernel allows Privilege Escalation. An improper Update of Reference Count in io_uring leads to Use-After-Free and Local Privilege Escalation. When io_msg_ring was invoked with a fixed file, it called io_fput_file() which improperly decreased its reference count (leading to Use-After-Free and Local Privilege Escalation). Fixed files are permanently registered to the ring, and should not be put separately.
References
https://kernel.dance/#fc7222c3a9f56271fba02aabbfbae999042f1679
https://github.com/torvalds/linux/commit/fc7222c3a9f56271fba02aabbfbae999042f1679