From 12663bfc97c8b3fdb292428105dd92d563164050 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sasha.levin@oracle.com>
Date: Sat, 7 Dec 2013 17:26:27 -0500
Subject: net: unix: allow set_peek_off to fail

unix_dgram_recvmsg() will hold the readlock of the socket until recv
is complete.

In the same time, we may try to setsockopt(SO_PEEK_OFF) which will hang until
unix_dgram_recvmsg() will complete (which can take a while) without allowing
us to break out of it, triggering a hung task spew.

Instead, allow set_peek_off to fail, this way userspace will not hang.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/unix/af_unix.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'net/unix/af_unix.c')

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 01625ccc3ae6..a0ca162e5bd5 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -530,13 +530,17 @@ static int unix_seqpacket_sendmsg(struct kiocb *, struct socket *,
 static int unix_seqpacket_recvmsg(struct kiocb *, struct socket *,
 				  struct msghdr *, size_t, int);
 
-static void unix_set_peek_off(struct sock *sk, int val)
+static int unix_set_peek_off(struct sock *sk, int val)
 {
 	struct unix_sock *u = unix_sk(sk);
 
-	mutex_lock(&u->readlock);
+	if (mutex_lock_interruptible(&u->readlock))
+		return -EINTR;
+
 	sk->sk_peek_off = val;
 	mutex_unlock(&u->readlock);
+
+	return 0;
 }
 
 
-- 
cgit v1.2.3


From 37ab4fa7844a044dc21fde45e2a0fc2f3c3b6490 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sasha.levin@oracle.com>
Date: Fri, 13 Dec 2013 10:54:22 -0500
Subject: net: unix: allow bind to fail on mutex lock

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@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/unix/af_unix.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

(limited to 'net/unix/af_unix.c')

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a0ca162e5bd5..a427623ee574 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)
-- 
cgit v1.2.3