[3.11.y.z extended stable] Patch "net: unix: allow bind to fail on mutex lock" has been added to staging queue

Luis Henriques luis.henriques at canonical.com
Mon Jan 13 14:43:51 UTC 2014


This is a note to let you know that I have just added a patch titled

    net: unix: allow bind to fail on mutex lock

to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.11.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From b36bb708756d3a8d24f159da49603fc1e00bf8d7 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sasha.levin at oracle.com>
Date: Fri, 13 Dec 2013 10:54:22 -0500
Subject: net: unix: allow bind to fail on mutex lock

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





More information about the kernel-team mailing list