ipv4: fix memory leaks in ip_cmsg_send() callers

commit 919483096bfe75dda338e98d56da91a263746a0a upstream.

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>
[ luis: backported to 3.16: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 7aa584c36c15d52b6df5157052b104142eb0ec79..c7ec866adac98bb4c1d6901c5966071850e7335e 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -216,6 +216,8 @@ int ip_cmsg_send(struct net *net, struct msghdr *msg, struct ipcm_cookie *ipc,
                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)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index 30d0a64be4130c89315e75ecd89398108a35af89..9c68e94cd66d44e9713225e45261cc22261cc11f 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -748,8 +748,10 @@ static int ping_v4_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
 
        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;
        }

diff --git a/net/ipv4/raw.c b/net/ipv4/raw.c
index 2c65160565e1a084b5ff13832cfdb80d50ba7d6c..29ad1c63e2eac65dab033040acf886b0ff39045f 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -525,8 +525,10 @@ static int raw_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
        if (msg->msg_controllen) {
                err = ip_cmsg_send(sock_net(sk), msg, &ipc, false);
-               if (err)
+               if (unlikely(err)) {
+                       kfree(ipc.opt);
                        goto out;
+               }
                if (ipc.opt)
                        free = 1;
        }

diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index 2478b20692e86c9c930b600834a2965ac93f94f9..716475fc884b5407226267eb066313d2b3249360 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -972,8 +972,10 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
        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;