Subject: [PATCH 06/55] ipv4: fix memory leaks in udp_sendmsg, ping_v4_sendmsg

From: Andrey Ignatov <[email-masked]>
Date: Thu, 10 May 2018 10:59:34 -0700

[ Upstream commit 1b97013bfb11d66f041de691de6f0fec748ce016 ]

Fix more memory leaks in ip_cmsg_send() callers. Part of them were fixed
earlier in 919483096bfe.

* udp_sendmsg one was there since the beginning when linux sources were
  first added to git;
* ping_v4_sendmsg one was copy/pasted in c319b4d76b9e.

Whenever return happens in udp_sendmsg() or ping_v4_sendmsg() IP options
have to be freed if they were allocated previously.

Add label so that future callers (if any) can use it instead of kfree()
before return that is easy to forget.

Fixes: c319b4d76b9e (net: ipv4: add IPPROTO_ICMP socket kind)
Signed-off-by: Andrey Ignatov <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 net/ipv4/ping.c | 7 +++++--
 net/ipv4/udp.c  | 7 +++++--
 2 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c
index b8f0db54b197..16226d49263d 100644
--- a/net/ipv4/ping.c
+++ b/net/ipv4/ping.c
@@ -775,8 +775,10 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	ipc.addr = faddr = daddr;
 
 	if (ipc.opt && ipc.opt->opt.srr) {
-		if (!daddr)
-			return -EINVAL;
+		if (!daddr) {
+			err = -EINVAL;
+			goto out_free;
+		}
 		faddr = ipc.opt->opt.faddr;
 	}
 	tos = get_rttos(&ipc, inet);
@@ -842,6 +844,7 @@ static int ping_v4_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 out:
 	ip_rt_put(rt);
+out_free:
 	if (free)
 		kfree(ipc.opt);
 	if (!err) {
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index e5ef7c38c934..fb5992988450 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -958,8 +958,10 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 	sock_tx_timestamp(sk, ipc.sockc.tsflags, &ipc.tx_flags);
 
 	if (ipc.opt && ipc.opt->opt.srr) {
-		if (!daddr)
-			return -EINVAL;
+		if (!daddr) {
+			err = -EINVAL;
+			goto out_free;
+		}
 		faddr = ipc.opt->opt.faddr;
 		connected = 0;
 	}
@@ -1080,6 +1082,7 @@ int udp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len)
 
 out:
 	ip_rt_put(rt);
+out_free:
 	if (free)
 		kfree(ipc.opt);
 	if (!err)
-- 
2.14.3