netdev - [PATCH net-next 2/2] tcp: lockless TCP

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250821141901.18839-3-edumazet@google.com>
Date: Thu, 21 Aug 2025 14:19:01 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>, Neal Cardwell <ncardwell@...gle.com>
Cc: Simon Horman <horms@...nel.org>, Kuniyuki Iwashima <kuniyu@...gle.com>, 
	Willem de Bruijn <willemb@...gle.com>, netdev@...r.kernel.org, eric.dumazet@...il.com, 
	Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net-next 2/2] tcp: lockless TCP_MAXSEG option

setsockopt(TCP_MAXSEG) writes over a field that does not need
socket lock protection anymore.

Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
 net/ipv4/tcp.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index a12d81e01b3f2fb964227881c2f779741cc06e58..99232903b03c99d263cce59314fd369cfd33af6f 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -3890,15 +3890,13 @@ int do_tcp_setsockopt(struct sock *sk, int level, int optname,
 		WRITE_ONCE(inet_csk(sk)->icsk_delack_max, delack_max);
 		return 0;
 	}
+	case TCP_MAXSEG:
+		return tcp_sock_set_maxseg(sk, val);
 	}
 
 	sockopt_lock_sock(sk);
 
 	switch (optname) {
-	case TCP_MAXSEG:
-		err = tcp_sock_set_maxseg(sk, val);
-		break;
-
 	case TCP_NODELAY:
 		__tcp_sock_set_nodelay(sk, val);
 		break;
-- 
2.51.0.rc1.193.gad69d77794-goog