[PATCH 5.16 0953/1017] io_uring: fix memory leak of uid in files registration

[Greg Kroah-Hartman]

From: Pavel Begunkov <asml.silence@xxxxxxxxx>

commit c86d18f4aa93e0e66cda0e55827cd03eea6bc5f8 upstream.

When there are no files for __io_sqe_files_scm() to process in the
range, it'll free everything and return. However, it forgets to put uid.

Fixes: 08a451739a9b5 ("io_uring: allow sparse fixed file sets")
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Link: https://lore.kernel.org/r/accee442376f33ce8aaebb099d04967533efde92.1648226048.git.asml.silence@xxxxxxxxx
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 fs/io_uring.c |    1 +
 1 file changed, 1 insertion(+)

--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8180,6 +8180,7 @@ static int __io_sqe_files_scm(struct io_
 			fput(fpl->fp[i]);
 	} else {
 		kfree_skb(skb);
+		free_uid(fpl->user);
 		kfree(fpl);
 	}