In the Linux kernel, the following vulnerability has been resolved: io_uring: preserve task restrictions across exec Per-task restrictions

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

io_uring: preserve task restrictions across exec

Per-task restrictions apply to all rings created by a task. Once
installed, they should not be dropped across exec.

For a task that has used io_uring, the exec cancellation path calls
__io_uring_free(). This frees both the task context and the per-task
restriction, so a ring created after exec is unrestricted.

Split task context cleanup into io_uring_free_tctx(), and use it from
the exec cancellation path. Keep __io_uring_free() for final task
cleanup, where both the context and restriction are released.