Patch "ipv4: fix memory leaks in ip_cmsg_send() callers" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

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

    ipv4: fix memory leaks in ip_cmsg_send() callers

to the 4.4-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:
     ipv4-fix-memory-leaks-in-ip_cmsg_send-callers.patch
and it can be found in the queue-4.4 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 Mon Feb 29 14:33:50 PST 2016
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 4 Feb 2016 06:23:28 -0800
Subject: ipv4: fix memory leaks in ip_cmsg_send() callers

From: Eric Dumazet <edumazet@google.com>

[ Upstream commit 919483096bfe75dda338e98d56da91a263746a0a ]

Dmitry reported memory leaks of IP options allocated in
ip_cmsg_send() when/if this function returns an error.

Callers are responsible for the freeing.

Many thanks to Dmitry for the report and diagnostic.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/ipv4/ip_sockglue.c |    2 ++
 net/ipv4/ping.c        |    4 +++-
 net/ipv4/raw.c         |    4 +++-
 net/ipv4/udp.c         |    4 +++-
 4 files changed, 11 insertions(+), 3 deletions(-)

--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -249,6 +249,8 @@ int ip_cmsg_send(struct net *net, struct
 		switch (cmsg->cmsg_type) {
 		case IP_RETOPTS:
 			err = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
+
+			/* Our caller is responsible for freeing ipc->opt */
 			err = ip_options_get(net, &ipc->opt, CMSG_DATA(cmsg),
 					     err < 40 ? err : 40);
 			if (err)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -746,8 +746,10 @@ static int ping_v4_sendmsg(struct sock *
 
 	if (msg->msg_controllen) {
 		err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
-		if (err)
+		if (unlikely(err)) {
+			kfree(ipc.opt);
 			return err;
+		}
 		if (ipc.opt)
 			free = 1;
 	}
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -547,8 +547,10 @@ static int raw_sendmsg(struct sock *sk,
 
 	if (msg->msg_controllen) {
 		err = ip_cmsg_send(net, msg, &ipc, false);
-		if (err)
+		if (unlikely(err)) {
+			kfree(ipc.opt);
 			goto out;
+		}
 		if (ipc.opt)
 			free = 1;
 	}
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -966,8 +966,10 @@ int udp_sendmsg(struct sock *sk, struct
 	if (msg->msg_controllen) {
 		err = ip_cmsg_send(sock_net(sk), msg, &ipc,
 				   sk->sk_family == AF_INET6);
-		if (err)
+		if (unlikely(err)) {
+			kfree(ipc.opt);
 			return err;
+		}
 		if (ipc.opt)
 			free = 1;
 		connected = 0;


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

queue-4.4/ipv4-fix-memory-leaks-in-ip_cmsg_send-callers.patch
queue-4.4/tcp-dccp-fix-another-race-at-listener-dismantle.patch
queue-4.4/ipv6-fix-a-lockdep-splat.patch
queue-4.4/ipv6-addrconf-fix-recursive-spin-lock-call.patch
queue-4.4/tcp-do-not-drop-syn_recv-on-all-icmp-reports.patch
queue-4.4/tcp-beware-of-alignments-in-tcp_get_info.patch
queue-4.4/tcp-md5-release-request-socket-instead-of-listener.patch
queue-4.4/gro-make-gro-aware-of-lightweight-tunnels.patch
queue-4.4/tcp-fix-null-deref-in-tcp_v4_send_ack.patch
queue-4.4/af_unix-fix-struct-pid-memory-leak.patch
queue-4.4/net-add-sysctl_max_skb_frags.patch