ipv4: fix memory leaks in ip_cmsg_send() callers

[ 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>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index 043d882..b3648bb 100644 (file)
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c
@@ -206,6 +206,8 @@ 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 7aa6225..5d28677 100644 (file)
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -530,8 +530,10 @@ static int ping_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
 
        if (msg->msg_controllen) {
                err = ip_cmsg_send(sock_net(sk), msg, &ipc);
-               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 063bcd5..e643096 100644 (file)
--- a/net/ipv4/raw.c
+++ b/net/ipv4/raw.c
@@ -520,8 +520,10 @@ 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);
-               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 f602611..f64a1e5 100644 (file)
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -875,8 +875,10 @@ int udp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
                return err;
        if (msg->msg_controllen) {
                err = ip_cmsg_send(sock_net(sk), msg, &ipc);
-               if (err)
+               if (unlikely(err)) {
+                       kfree(ipc.opt);
                        return err;
+               }
                if (ipc.opt)
                        free = 1;
                connected = 0;