This is a note to let you know that I've just added the patch titled
tcp: add tcp_done_with_error() helper
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
tcp-add-tcp_done_with_error-helper.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 37b3e87f385325a0a16f7040570278404ef14276
Author: Eric Dumazet <edumazet@xxxxxxxxxx>
Date: Tue May 28 12:52:50 2024 +0000
tcp: add tcp_done_with_error() helper
[ Upstream commit 5e514f1cba090e1c8fff03e92a175eccfe46305f ]
tcp_reset() ends with a sequence that is carefuly ordered.
We need to fix [e]poll bugs in the following patches,
it makes sense to use a common helper.
Suggested-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Acked-by: Neal Cardwell <ncardwell@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20240528125253.1966136-2-edumazet@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Stable-dep-of: 853c3bd7b791 ("tcp: fix race in tcp_write_err()")
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/include/net/tcp.h b/include/net/tcp.h
index 30f8111f750b5..061e15a1ac87d 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -612,6 +612,7 @@ void tcp_skb_collapse_tstamp(struct sk_buff *skb,
/* tcp_input.c */
void tcp_rearm_rto(struct sock *sk);
void tcp_synack_rtt_meas(struct sock *sk, struct request_sock *req);
+void tcp_done_with_error(struct sock *sk, int err);
void tcp_reset(struct sock *sk, struct sk_buff *skb);
void tcp_skb_mark_lost_uncond_verify(struct tcp_sock *tp, struct sk_buff *skb);
void tcp_fin(struct sock *sk);
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index db3bfe1a8443c..3c85ecab14457 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -592,7 +592,7 @@ __poll_t tcp_poll(struct file *file, struct socket *sock, poll_table *wait)
*/
mask |= EPOLLOUT | EPOLLWRNORM;
}
- /* This barrier is coupled with smp_wmb() in tcp_reset() */
+ /* This barrier is coupled with smp_wmb() in tcp_done_with_error() */
smp_rmb();
if (READ_ONCE(sk->sk_err) ||
!skb_queue_empty_lockless(&sk->sk_error_queue))
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index bb20ae8dba09b..c51ad6b353eef 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4348,9 +4348,26 @@ static inline bool tcp_sequence(const struct tcp_sock *tp, u32 seq, u32 end_seq)
!after(seq, tp->rcv_nxt + tcp_receive_window(tp));
}
+
+void tcp_done_with_error(struct sock *sk, int err)
+{
+ /* This barrier is coupled with smp_rmb() in tcp_poll() */
+ WRITE_ONCE(sk->sk_err, err);
+ smp_wmb();
+
+ tcp_write_queue_purge(sk);
+ tcp_done(sk);
+
+ if (!sock_flag(sk, SOCK_DEAD))
+ sk_error_report(sk);
+}
+EXPORT_SYMBOL(tcp_done_with_error);
+
/* When we get a reset we do this. */
void tcp_reset(struct sock *sk, struct sk_buff *skb)
{
+ int err;
+
trace_tcp_receive_reset(sk);
/* mptcp can't tell us to ignore reset pkts,
@@ -4362,24 +4379,17 @@ void tcp_reset(struct sock *sk, struct sk_buff *skb)
/* We want the right error as BSD sees it (and indeed as we do). */
switch (sk->sk_state) {
case TCP_SYN_SENT:
- WRITE_ONCE(sk->sk_err, ECONNREFUSED);
+ err = ECONNREFUSED;
break;
case TCP_CLOSE_WAIT:
- WRITE_ONCE(sk->sk_err, EPIPE);
+ err = EPIPE;
break;
case TCP_CLOSE:
return;
default:
- WRITE_ONCE(sk->sk_err, ECONNRESET);
+ err = ECONNRESET;
}
- /* This barrier is coupled with smp_rmb() in tcp_poll() */
- smp_wmb();
-
- tcp_write_queue_purge(sk);
- tcp_done(sk);
-
- if (!sock_flag(sk, SOCK_DEAD))
- sk_error_report(sk);
+ tcp_done_with_error(sk, err);
}
/*
