In the Linux kernel, the following vulnerability has been resolved:
pipe: wakeup wr_wait after setting max_usage
Commit c73be61cede5 (“pipe: Add general notification queue support”) a
regression was introduced that would lock up resized pipes under certain
conditions. See the reproducer in [1].
The commit resizing the pipe ring size was moved to a different
function, doing that moved the wakeup for pipe->wr_wait before actually
raising pipe->max_usage. If a pipe was full before the resize occured it
would result in the wakeup never actually triggering pipe_write.
Set @max_usage and @nr_accounted before waking writers if this isn’t a
watch queue.
[Christian Brauner <[email protected]>: rewrite to account for watch queues]
git.kernel.org/stable/c/162ae0e78bdabf84ef10c1293c4ed7865cb7d3c8
git.kernel.org/stable/c/3efbd114b91525bb095b8ae046382197d92126b9
git.kernel.org/stable/c/68e51bdb1194f11d3452525b99c98aff6f837b24
git.kernel.org/stable/c/6fb70694f8d1ac34e45246b0ac988f025e1e5b55
git.kernel.org/stable/c/b87a1229d8668fbc78ebd9ca0fc797a76001c60f
git.kernel.org/stable/c/e95aada4cb93d42e25c30a0ef9eb2923d9711d4a