loop_rw_iter in fs/io_uring.c in the Linux kernel 5.10 through 5.14.6 allows local users to gain privileges by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer, as demonstrated by using /proc/<pid>/maps for exploitation.
https://www.debian.org/security/2021/dsa-4978
https://security.netapp.com/advisory/ntap-20211014-0003/