[PATCH 3.11 179/208] net: unix: allow bind to fail on mutex lock

[Luis Henriques]

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

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

From: Sasha Levin <sasha.levin at oracle.com>

commit 37ab4fa7844a044dc21fde45e2a0fc2f3c3b6490 upstream.

This is similar to the set_peek_off patch where calling bind while the
socket is stuck in unix_dgram_recvmsg() will block and cause a hung task
spew after a while.

This is also the last place that did a straightforward mutex_lock(), so
there shouldn't be any more of these patches.

Signed-off-by: Sasha Levin <sasha.levin at oracle.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/unix/af_unix.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 303dcec..f246812 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -718,7 +718,9 @@ static int unix_autobind(struct socket *sock)
 	int err;
 	unsigned int retries = 0;
 
-	mutex_lock(&u->readlock);
+	err = mutex_lock_interruptible(&u->readlock);
+	if (err)
+		return err;
 
 	err = 0;
 	if (u->addr)
@@ -877,7 +879,9 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 		goto out;
 	addr_len = err;
 
-	mutex_lock(&u->readlock);
+	err = mutex_lock_interruptible(&u->readlock);
+	if (err)
+		goto out;
 
 	err = -EINVAL;
 	if (u->addr)
-- 
1.8.3.2