2024-01-29 09:23:53

by Zhipeng Lu

Subject: [PATCH] [v2] net: ipv4: fix a memleak in ip_setup_cork

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 <[email protected]>
---
Changelog:

v2: fix memleak by placing the malloc as the last error-handling.
---
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 b06f678b03a1..41537d18eecf 100644
--- a/net/ipv4/ip_output.c
+++ b/net/ipv4/ip_output.c
@@ -1287,6 +1287,12 @@ 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.
*/
@@ -1303,12 +1309,6 @@ 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;
--
2.34.1

2024-01-29 13:23:21

by Eric Dumazet

Subject: Re: [PATCH] [v2] net: ipv4: fix a memleak in ip_setup_cork

On Mon, Jan 29, 2024 at 10:23 AM Zhipeng Lu <[email protected]> wrote:
>
> 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 <[email protected]>
> ---

Okay, although the changelog is a bit confusing, since we do not free
cork->opt anymore in V2...

Reviewed-by: Eric Dumazet <[email protected]>

2024-02-01 00:26:43

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] [v2] net: ipv4: fix a memleak in ip_setup_cork

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <[email protected]>:

On Mon, 29 Jan 2024 17:10:17 +0800 you wrote:
> 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 <[email protected]>
> ---
> Changelog:
>
> [...]

Here is the summary with links:
- [v2] net: ipv4: fix a memleak in ip_setup_cork
https://git.kernel.org/netdev/net/c/5dee6d692345

You are awesome, thank you!
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