[PATCH 6.1 207/219] net: ipv4: fix a memleak in ip_setup_cork

Greg Kroah-Hartman
2024-02-03T04:11:20Z

From: Zhipeng Lu <alexious@zju.edu.cn>

[ Upstream commit 5dee6d6923458e26966717f2a3eae7d09fc10bf6 ]

When inetdev_valid_mtu fails, cork->opt should be freed if it is
allocated in ip_setup_cork. Otherwise there could be a memleak.

Fixes: 501a90c94510 ("inet: protect against too small mtu values.")
Signed-off-by: Zhipeng Lu <alexious@zju.edu.cn>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240129091017.2938835-1-alexious@zju.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/ipv4/ip_output.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/net/ipv4/ip_output.c b/net/ipv4/ip_output.c
index e19ef88ae181..a6d460aaee79 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1268,6 +1268,12 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
if (unlikely(!rt))
return -EFAULT;

+ cork->fragsize = ip_sk_use_pmtu(sk) ?
+ dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);
+
+ if (!inetdev_valid_mtu(cork->fragsize))
+ return -ENETUNREACH;
+
/*
* setup for corking.
*/
@@ -1284,12 +1290,6 @@ static int ip_setup_cork(struct sock *sk, struct inet_cork *cork,
cork->addr = ipc->addr;
}

- cork->fragsize = ip_sk_use_pmtu(sk) ?
- dst_mtu(&rt->dst) : READ_ONCE(rt->dst.dev->mtu);
-
- if (!inetdev_valid_mtu(cork->fragsize))
- return -ENETUNREACH;
-
cork->gso_size = ipc->gso_size;

cork->dst = &rt->dst;
--
2.43.0