netdev - [PATCH] net: l2tp: unlock socket lock before returning from l2tp_ip

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Date:	Wed,  2 May 2012 15:10:37 +0200
From:	Sasha Levin <levinsasha928@...il.com>
To:	davem@...emloft.net, jchapman@...alix.com, eric.dumazet@...il.com
Cc:	netdev@...r.kernel.org, linux-kernel@...r.kernel.org,
	davej@...hat.com, Sasha Levin <levinsasha928@...il.com>
Subject: [PATCH] net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg

l2tp_ip_sendmsg could return without releasing socket lock, making it all the
way to userspace, and generating the following warning:

[  130.891594] ================================================
[  130.894569] [ BUG: lock held when returning to user space! ]
[  130.897257] 3.4.0-rc5-next-20120501-sasha #104 Tainted: G        W
[  130.900336] ------------------------------------------------
[  130.902996] trinity/8384 is leaving the kernel with locks still held!
[  130.906106] 1 lock held by trinity/8384:
[  130.907924]  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff82b9503f>] l2tp_ip_sendmsg+0x2f/0x550

Signed-off-by: Sasha Levin <levinsasha928@...il.com>
---
 net/l2tp/l2tp_ip.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/net/l2tp/l2tp_ip.c b/net/l2tp/l2tp_ip.c
index 585d93e..a4d8364 100644
--- a/net/l2tp/l2tp_ip.c
+++ b/net/l2tp/l2tp_ip.c
@@ -442,8 +442,10 @@ static int l2tp_ip_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
 
 		daddr = lip->l2tp_addr.s_addr;
 	} else {
-		if (sk->sk_state != TCP_ESTABLISHED)
-			return -EDESTADDRREQ;
+		if (sk->sk_state != TCP_ESTABLISHED) {
+			rc = -EDESTADDRREQ;
+			goto out;
+		}
 
 		daddr = inet->inet_daddr;
 		connected = 1;
-- 
1.7.8.5

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