linux-kernel - [PATCH 3.5 82/96] net: unix: allow set_peek

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1389623099-18783-83-git-send-email-luis.henriques@canonical.com>
Date:	Mon, 13 Jan 2014 14:24:45 +0000
From:	Luis Henriques <luis.henriques@...onical.com>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org,
	kernel-team@...ts.ubuntu.com
Cc:	Sasha Levin <sasha.levin@...cle.com>,
	"David S. Miller" <davem@...emloft.net>,
	Luis Henriques <luis.henriques@...onical.com>
Subject: [PATCH 3.5 82/96] net: unix: allow set_peek_off to fail

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

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

From: Sasha Levin <sasha.levin@...cle.com>

commit 12663bfc97c8b3fdb292428105dd92d563164050 upstream.

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@...cle.com>
Acked-by: Pavel Emelyanov <xemul@...allels.com>
Signed-off-by: David S. Miller <davem@...emloft.net>
Signed-off-by: Luis Henriques <luis.henriques@...onical.com>
---
 include/linux/net.h | 2 +-
 net/core/sock.c     | 2 +-
 net/unix/af_unix.c  | 8 ++++++--
 3 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/net.h b/include/linux/net.h
index f150cdf..2ece444 100644
--- a/include/linux/net.h
+++ b/include/linux/net.h
@@ -215,7 +215,7 @@ struct proto_ops {
 				      int offset, size_t size, int flags);
 	ssize_t 	(*splice_read)(struct socket *sock,  loff_t *ppos,
 				       struct pipe_inode_info *pipe, size_t len, unsigned int flags);
-	void		(*set_peek_off)(struct sock *sk, int val);
+	int		(*set_peek_off)(struct sock *sk, int val);
 };
 
 #define DECLARE_SOCKADDR(type, dst, src)	\
diff --git a/net/core/sock.c b/net/core/sock.c
index 457ae99..5057305 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -787,7 +787,7 @@ set_rcvbuf:
 
 	case SO_PEEK_OFF:
 		if (sock->ops->set_peek_off)
-			sock->ops->set_peek_off(sk, val);
+			ret = sock->ops->set_peek_off(sk, val);
 		else
 			ret = -EOPNOTSUPP;
 		break;
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index a0df32b..692d780 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -525,13 +525,17 @@ 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;
 }
 
 
-- 
1.8.3.2

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/