[PATCH net] tcp: Use WARN_ON_ONCE() in tcp_read_skb()

[PATCH net] tcp: Use WARN_ON_ONCE() in tcp_read_skb()

[Peilin Ye]

From: Peilin Ye <peilin.ye@bytedance.com>

Prevent tcp_read_skb() from flooding the syslog.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
---
 net/ipv4/tcp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8230be00ecca..9251c99d3cfd 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1766,7 +1766,7 @@ int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 		return 0;
 
 	__skb_unlink(skb, &sk->sk_receive_queue);
-	WARN_ON(!skb_set_owner_sk_safe(skb, sk));
+	WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
 	copied = recv_actor(sk, skb);
 	if (copied >= 0) {
 		seq += copied;
-- 
2.20.1

[PATCH net v2] net: Use WARN_ON_ONCE() in {tcp,udp}_read_skb()

[Peilin Ye]

From: Peilin Ye <peilin.ye@bytedance.com>

Prevent tcp_read_skb() and udp_read_skb() from flooding the syslog.

Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
---
change since v1:
  - do the same to udp_read_skb() (Cong Wang)

Cong's tcp_read_skb() fix [1] depends on this patch.

[1] https://lore.kernel.org/netdev/20220912173553.235838-1-xiyou.wangcong@gmail.com/

Thanks,
Peilin Ye

 net/ipv4/tcp.c | 2 +-
 net/ipv4/udp.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 8230be00ecca..9251c99d3cfd 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1766,7 +1766,7 @@ int tcp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 		return 0;
 
 	__skb_unlink(skb, &sk->sk_receive_queue);
-	WARN_ON(!skb_set_owner_sk_safe(skb, sk));
+	WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
 	copied = recv_actor(sk, skb);
 	if (copied >= 0) {
 		seq += copied;
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c
index cd72158e953a..560d9eadeaa5 100644
--- a/net/ipv4/udp.c
+++ b/net/ipv4/udp.c
@@ -1821,7 +1821,7 @@ int udp_read_skb(struct sock *sk, skb_read_actor_t recv_actor)
 			continue;
 		}
 
-		WARN_ON(!skb_set_owner_sk_safe(skb, sk));
+		WARN_ON_ONCE(!skb_set_owner_sk_safe(skb, sk));
 		used = recv_actor(sk, skb);
 		if (used <= 0) {
 			if (!copied)
-- 
2.20.1

Re: [PATCH net v2] net: Use WARN_ON_ONCE() in {tcp,udp}_read_skb()

[Peilin Ye]

On Tue, Sep 13, 2022 at 11:40:16AM -0700, Peilin Ye wrote:
> Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
> Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>

Sorry, I forgot to add Fixes: tag.

Those WARN_ON() come from different commits.  I will split this into two
in v3 to make it easier.

Thanks,
Peilin Ye

Re: [PATCH net v2] net: Use WARN_ON_ONCE() in {tcp,udp}_read_skb()

[Peilin Ye]

On Tue, Sep 13, 2022 at 12:30:50PM -0700, Peilin Ye wrote:
> On Tue, Sep 13, 2022 at 11:40:16AM -0700, Peilin Ye wrote:
> > Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
> > Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
> 
> Sorry, I forgot to add Fixes: tag.
> 
> Those WARN_ON() come from different commits.  I will split this into two
> in v3 to make it easier.

Cong suggested not sending v3 since this is not fixing a bug, and thus
no need to add Fixes: tags.

Re: [PATCH net] tcp: Use WARN_ON_ONCE() in tcp_read_skb()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:

On Thu,  8 Sep 2022 16:15:23 -0700 you wrote:
> From: Peilin Ye <peilin.ye@bytedance.com>
> 
> Prevent tcp_read_skb() from flooding the syslog.
> 
> Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
> Signed-off-by: Peilin Ye <peilin.ye@bytedance.com>
> 
> [...]

Here is the summary with links:
  - [net] tcp: Use WARN_ON_ONCE() in tcp_read_skb()
    https://git.kernel.org/netdev/net/c/96628951869c

You are awesome, thank you!
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