[PATCH 1/1] io_uring/zcrx: fix user_struct uaf

[Pavel Begunkov <asml.silence@gmail.com>]

io_free_rbuf_ring() usees a struct user_struct, which
io_zcrx_ifq_free() puts it down before destroying the ring.

Cc: stable@vger.kernel.org
Fixes: 5c686456a4e83 ("io_uring/zcrx: add user_struct and mm_struct to io_zcrx_ifq")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 io_uring/zcrx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c
index 9a83d7eb4210..fab3693ecb0d 100644
--- a/io_uring/zcrx.c
+++ b/io_uring/zcrx.c
@@ -579,13 +579,13 @@ static void io_zcrx_ifq_free(struct io_zcrx_ifq *ifq)
 
 	if (ifq->area)
 		io_zcrx_free_area(ifq, ifq->area);
-	free_uid(ifq->user);
 	if (ifq->mm_account)
 		mmdrop(ifq->mm_account);
 	if (ifq->dev)
 		put_device(ifq->dev);
 
 	io_free_rbuf_ring(ifq);
+	free_uid(ifq->user);
 	mutex_destroy(&ifq->pp_lock);
 	kfree(ifq);
 }
-- 
2.53.0