Merge branch 'keys-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs

Pull watch_queue fixes from David Howells:
 "Here are fixes for a couple more watch_queue bugs, both found by syzbot:

   - Fix error cleanup in watch_queue_set_size() where it tries to clean
     up all the pointers in the page list, even if they've not been
     allocated yet[1]. Unfortunately, __free_page() doesn't treat a NULL
     pointer as being "do nothing".

     A second report[2] looks like it's probably the same bug, but on
     arm64 rather than x86_64, but there's no reproducer.

   - Fix a missing kfree in free_watch() to actually free the watch[3]"

Link: https://lore.kernel.org/r/000000000000b1807c05daad8f98@google.com/ [1]
Link: https://lore.kernel.org/r/000000000000035b9c05daae8a5e@google.com/ [2]
Link: https://lore.kernel.org/r/000000000000bc8eaf05dab91c63@google.com/ [3]

* 'keys-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
  watch_queue: Actually free the watch
  watch_queue: Fix NULL dereference in error cleanup

kernel/watch_queue.c

@@ -271,7 +271,7 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes)
 	return 0;
 
 error_p:
-	for (i = 0; i < nr_pages; i++)
+	while (--i >= 0)
 		__free_page(pages[i]);
 	kfree(pages);
 error:
@@ -395,6 +395,7 @@ static void free_watch(struct rcu_head *rcu)
 	put_watch_queue(rcu_access_pointer(watch->queue));
 	atomic_dec(&watch->cred->user->nr_watches);
 	put_cred(watch->cred);
+	kfree(watch);
 }
 
 static void __put_watch(struct kref *kref)