diff mbox series

[stable-5.4,1/4] tcp: refactor tcp_retransmit_timer()

Message ID 20240716015401.2365503-2-edumazet@google.com (mailing list archive)
State Not Applicable
Delegated to: Netdev Maintainers
Headers show
Series tcp: stable backports for CVE-2024-41007 | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Eric Dumazet July 16, 2024, 1:53 a.m. UTC 
commit 0d580fbd2db084a5c96ee9c00492236a279d5e0f upstream.

It appears linux-4.14 stable needs a backport of commit
88f8598d0a30 ("tcp: exit if nothing to retransmit on RTO timeout")

Since tcp_rtx_queue_empty() is not in pre 4.15 kernels,
let's refactor tcp_retransmit_timer() to only use tcp_rtx_queue_head()

I will provide to stable teams the squashed patches.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
 net/ipv4/tcp_timer.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/tcp_timer.c b/net/ipv4/tcp_timer.c
index e20fced3c9cf691c83b494e11e551161e17d6619..e0bd7999d6d51602fcd868a72d00618234bd0c27 100644
--- a/net/ipv4/tcp_timer.c
+++ b/net/ipv4/tcp_timer.c
@@ -452,6 +452,7 @@  void tcp_retransmit_timer(struct sock *sk)
 	struct net *net = sock_net(sk);
 	struct inet_connection_sock *icsk = inet_csk(sk);
 	struct request_sock *req;
+	struct sk_buff *skb;
 
 	req = rcu_dereference_protected(tp->fastopen_rsk,
 					lockdep_sock_is_held(sk));
@@ -464,7 +465,12 @@  void tcp_retransmit_timer(struct sock *sk)
 		 */
 		return;
 	}
-	if (!tp->packets_out || WARN_ON_ONCE(tcp_rtx_queue_empty(sk)))
+
+	if (!tp->packets_out)
+		return;
+
+	skb = tcp_rtx_queue_head(sk);
+	if (WARN_ON_ONCE(!skb))
 		return;
 
 	if (!tp->snd_wnd && !sock_flag(sk, SOCK_DEAD) &&
@@ -496,7 +502,7 @@  void tcp_retransmit_timer(struct sock *sk)
 			goto out;
 		}
 		tcp_enter_loss(sk);
-		tcp_retransmit_skb(sk, tcp_rtx_queue_head(sk), 1);
+		tcp_retransmit_skb(sk, skb, 1);
 		__sk_dst_reset(sk);
 		goto out_reset_timer;
 	}