Fix failure path in alloc_pid()

The failure path removes the allocated PIDs from the wrong namespace.
This could lead to us inadvertently reusing PIDs in the leaf namespace
and leaking PIDs in parent namespaces.

Fixes: 95846ecf9d ("pid: replace pid bitmap implementation with IDR API")
Cc: <stable@vger.kernel.org>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Matthew Wilcox 2018-12-28 07:22:26 -08:00 committed by Linus Torvalds
parent 00c569b567
commit 1a80dade01

View File

@ -233,8 +233,10 @@ out_unlock:
out_free:
spin_lock_irq(&pidmap_lock);
while (++i <= ns->level)
idr_remove(&ns->idr, (pid->numbers + i)->nr);
while (++i <= ns->level) {
upid = pid->numbers + i;
idr_remove(&upid->ns->idr, upid->nr);
}
/* On failure to allocate the first pid, reset the state */
if (ns->pid_allocated == PIDNS_ADDING)