Re: [PATCH 1/2] tcp: fix races in tcp_abort()

[Sasha Levin <sashal@xxxxxxxxxx>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
❌ Build failures detected

The upstream commit SHA1 provided is correct: 5ce4645c23cf5f048eb8e9ce49e514bababdee85

WARNING: Author mismatch between patch and upstream commit:
Backport author: Youngmin Nam<youngmin.nam@xxxxxxxxxxx>
Commit author: Eric Dumazet<edumazet@xxxxxxxxxx>

Note: The patch differs from the upstream commit:
---
Failed to apply patch cleanly.
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.13.y       |  Failed     |  N/A       |
| stable/linux-6.12.y       |  Failed     |  N/A       |
| stable/linux-6.6.y        |  Success    |  Success   |
| stable/linux-6.1.y        |  Success    |  Success   |
| stable/linux-5.15.y       |  Success    |  Success   |
| stable/linux-5.10.y       |  Failed     |  N/A       |
| stable/linux-5.4.y        |  Failed     |  N/A       |

Build Errors:
Patch failed to apply on stable/linux-6.13.y. Reject:

diff a/net/ipv4/tcp.c b/net/ipv4/tcp.c	(rejected hunks)
@@ -4630,13 +4630,9 @@ int tcp_abort(struct sock *sk, int err)
 	bh_lock_sock(sk);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
-		WRITE_ONCE(sk->sk_err, err);
-		/* This barrier is coupled with smp_rmb() in tcp_poll() */
-		smp_wmb();
-		sk_error_report(sk);
 		if (tcp_need_reset(sk->sk_state))
 			tcp_send_active_reset(sk, GFP_ATOMIC);
-		tcp_done(sk);
+		tcp_done_with_error(sk, err);
 	}
 
 	bh_unlock_sock(sk);
Patch failed to apply on stable/linux-6.12.y. Reject:

diff a/net/ipv4/tcp.c b/net/ipv4/tcp.c	(rejected hunks)
@@ -4630,13 +4630,9 @@ int tcp_abort(struct sock *sk, int err)
 	bh_lock_sock(sk);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
-		WRITE_ONCE(sk->sk_err, err);
-		/* This barrier is coupled with smp_rmb() in tcp_poll() */
-		smp_wmb();
-		sk_error_report(sk);
 		if (tcp_need_reset(sk->sk_state))
 			tcp_send_active_reset(sk, GFP_ATOMIC);
-		tcp_done(sk);
+		tcp_done_with_error(sk, err);
 	}
 
 	bh_unlock_sock(sk);
Patch failed to apply on stable/linux-5.10.y. Reject:

diff a/net/ipv4/tcp.c b/net/ipv4/tcp.c	(rejected hunks)
@@ -4630,13 +4630,9 @@ int tcp_abort(struct sock *sk, int err)
 	bh_lock_sock(sk);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
-		WRITE_ONCE(sk->sk_err, err);
-		/* This barrier is coupled with smp_rmb() in tcp_poll() */
-		smp_wmb();
-		sk_error_report(sk);
 		if (tcp_need_reset(sk->sk_state))
 			tcp_send_active_reset(sk, GFP_ATOMIC);
-		tcp_done(sk);
+		tcp_done_with_error(sk, err);
 	}
 
 	bh_unlock_sock(sk);
Patch failed to apply on stable/linux-5.4.y. Reject:

diff a/net/ipv4/tcp.c b/net/ipv4/tcp.c	(rejected hunks)
@@ -4630,13 +4630,9 @@ int tcp_abort(struct sock *sk, int err)
 	bh_lock_sock(sk);
 
 	if (!sock_flag(sk, SOCK_DEAD)) {
-		WRITE_ONCE(sk->sk_err, err);
-		/* This barrier is coupled with smp_rmb() in tcp_poll() */
-		smp_wmb();
-		sk_error_report(sk);
 		if (tcp_need_reset(sk->sk_state))
 			tcp_send_active_reset(sk, GFP_ATOMIC);
-		tcp_done(sk);
+		tcp_done_with_error(sk, err);
 	}
 
 	bh_unlock_sock(sk);