Patch "ipv6: lock socket in ip6_datagram_connect()" has been added to the 4.1-stable tree

Patch "ipv6: lock socket in ip6_datagram_connect()" has been added to the 4.1-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    ipv6: lock socket in ip6_datagram_connect()

to the 4.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     ipv6-lock-socket-in-ip6_datagram_connect.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Sat Sep 26 11:13:07 PDT 2015
From: Eric Dumazet <edumazet@google.com>
Date: Tue, 14 Jul 2015 08:10:22 +0200
Subject: ipv6: lock socket in ip6_datagram_connect()

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 03645a11a570d52e70631838cb786eb4253eb463 ]

ip6_datagram_connect() is doing a lot of socket changes without
socket being locked.

This looks wrong, at least for udp_lib_rehash() which could corrupt
lists because of concurrent udp_sk(sk)->udp_portaddr_hash accesses.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 include/net/ip.h    |    1 +
 net/ipv4/datagram.c |   16 ++++++++++++----
 net/ipv6/datagram.c |   20 +++++++++++++++-----
 3 files changed, 28 insertions(+), 9 deletions(-)

--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -161,6 +161,7 @@ static inline __u8 get_rtconn_flags(stru
 }
 
 /* datagram.c */
+int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len);
 
 void ip4_datagram_release_cb(struct sock *sk);
--- a/net/ipv4/datagram.c
+++ b/net/ipv4/datagram.c
@@ -20,7 +20,7 @@
 #include <net/route.h>
 #include <net/tcp_states.h>
 
-int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+int __ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 {
 	struct inet_sock *inet = inet_sk(sk);
 	struct sockaddr_in *usin = (struct sockaddr_in *) uaddr;
@@ -39,8 +39,6 @@ int ip4_datagram_connect(struct sock *sk
 
 	sk_dst_reset(sk);
 
-	lock_sock(sk);
-
 	oif = sk->sk_bound_dev_if;
 	saddr = inet->inet_saddr;
 	if (ipv4_is_multicast(usin->sin_addr.s_addr)) {
@@ -82,9 +80,19 @@ int ip4_datagram_connect(struct sock *sk
 	sk_dst_set(sk, &rt->dst);
 	err = 0;
 out:
-	release_sock(sk);
 	return err;
 }
+EXPORT_SYMBOL(__ip4_datagram_connect);
+
+int ip4_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	int res;
+
+	lock_sock(sk);
+	res = __ip4_datagram_connect(sk, uaddr, addr_len);
+	release_sock(sk);
+	return res;
+}
 EXPORT_SYMBOL(ip4_datagram_connect);
 
 /* Because UDP xmit path can manipulate sk_dst_cache without holding
--- a/net/ipv6/datagram.c
+++ b/net/ipv6/datagram.c
@@ -40,7 +40,7 @@ static bool ipv6_mapped_addr_any(const s
 	return ipv6_addr_v4mapped(a) && (a->s6_addr32[3] == 0);
 }
 
-int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+static int __ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
 {
 	struct sockaddr_in6	*usin = (struct sockaddr_in6 *) uaddr;
 	struct inet_sock	*inet = inet_sk(sk);
@@ -56,7 +56,7 @@ int ip6_datagram_connect(struct sock *sk
 	if (usin->sin6_family == AF_INET) {
 		if (__ipv6_only_sock(sk))
 			return -EAFNOSUPPORT;
-		err = ip4_datagram_connect(sk, uaddr, addr_len);
+		err = __ip4_datagram_connect(sk, uaddr, addr_len);
 		goto ipv4_connected;
 	}
 
@@ -98,9 +98,9 @@ int ip6_datagram_connect(struct sock *sk
 		sin.sin_addr.s_addr = daddr->s6_addr32[3];
 		sin.sin_port = usin->sin6_port;
 
-		err = ip4_datagram_connect(sk,
-					   (struct sockaddr *) &sin,
-					   sizeof(sin));
+		err = __ip4_datagram_connect(sk,
+					     (struct sockaddr *) &sin,
+					     sizeof(sin));
 
 ipv4_connected:
 		if (err)
@@ -204,6 +204,16 @@ out:
 	fl6_sock_release(flowlabel);
 	return err;
 }
+
+int ip6_datagram_connect(struct sock *sk, struct sockaddr *uaddr, int addr_len)
+{
+	int res;
+
+	lock_sock(sk);
+	res = __ip6_datagram_connect(sk, uaddr, addr_len);
+	release_sock(sk);
+	return res;
+}
 EXPORT_SYMBOL_GPL(ip6_datagram_connect);
 
 int ip6_datagram_connect_v6_only(struct sock *sk, struct sockaddr *uaddr,


Patches currently in stable-queue which might be from edumazet@google.com are

queue-4.1/udp-fix-dst-races-with-multicast-early-demux.patch
queue-4.1/fq_codel-fix-a-use-after-free.patch
queue-4.1/inet-fix-possible-request-socket-leak.patch
queue-4.1/ipv6-lock-socket-in-ip6_datagram_connect.patch
queue-4.1/net-fix-skb-csum-races-when-peeking.patch
queue-4.1/inet-fix-races-with-reqsk-timers.patch
queue-4.1/net-graceful-exit-from-netif_alloc_netdev_queues.patch
queue-4.1/bridge-fix-potential-crash-in-__netdev_pick_tx.patch
queue-4.1/inet-frags-fix-defragmented-packet-s-ip-header-for-af_packet.patch