[PATCH 4.9 03/36] kcm: Call strp_stop before strp_done in kcm_attach

From: Greg Kroah-Hartman
Date: Mon May 14 2018 - 02:53:46 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Tom Herbert <tom@xxxxxxxxxxxxxx>

commit dff8baa261174de689a44572d0ea182d7aa70598 upstream.

In kcm_attach strp_done is called when sk_user_data is already
set to fail the attach. strp_done needs the strp to be stopped and
warns if it isn't. Call strp_stop in this case to eliminate the
warning message.

Reported-by: syzbot+88dfb55e4c8b770d86e3@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: e5571240236c5652f ("kcm: Check if sk_user_data already set in kcm_attach"
Signed-off-by: Tom Herbert <tom@xxxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
net/kcm/kcmsock.c | 1 +
1 file changed, 1 insertion(+)

--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1424,6 +1424,7 @@ static int kcm_attach(struct socket *soc
*/
if (csk->sk_user_data) {
write_unlock_bh(&csk->sk_callback_lock);
+ strp_stop(&psock->strp);
strp_done(&psock->strp);
kmem_cache_free(kcm_psockp, psock);
err = -EALREADY;