From: Tom Herbert <tom@quantonium.net>
Date: Wed, 14 Feb 2018 17:22:42 +0000 (-0800)
Subject: kcm: Call strp_stop before strp_done in kcm_attach
X-Git-Tag: for-linus-20180413~64^2~427
X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=dff8baa26117;p=linux-block.git

kcm: Call strp_stop before strp_done in kcm_attach

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@syzkaller.appspotmail.com
Fixes: e5571240236c5652f ("kcm: Check if sk_user_data already set in kcm_attach"
Signed-off-by: Tom Herbert <tom@quantonium.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/kcm/kcmsock.c b/net/kcm/kcmsock.c
index f297d53a11aa..435594648dac 100644
--- a/net/kcm/kcmsock.c
+++ b/net/kcm/kcmsock.c
@@ -1417,6 +1417,7 @@ static int kcm_attach(struct socket *sock, struct socket *csock,
 	 */
 	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);
 		return -EALREADY;