netdev - [PATCH v2 net-next 1/2] tcp: replace smp_mb__after_atomic() with smp_mb() in 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]

Date:	Wed, 22 Jun 2016 11:32:50 -0400
From:	Jason Baron <jbaron@...mai.com>
To:	eric.dumazet@...il.com, davem@...emloft.net
Cc:	netdev@...r.kernel.org
Subject: [PATCH v2 net-next 1/2] tcp: replace smp_mb__after_atomic() with smp_mb() in tcp_poll()

From: Jason Baron <jbaron@...mai.com>

sock_reset_flag() maps to __clear_bit() not the atomic version clear_bit(),
hence we need an smp_mb() there, smp_mb__after_atomic() is not sufficient.

Fixes: 3c7151275c0c ("tcp: add memory barriers to write space paths")
Cc: Eric Dumazet <eric.dumazet@...il.com>
Signed-off-by: Jason Baron <jbaron@...mai.com>
---
 net/ipv4/tcp_input.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index 94d4aff97523..3ba526ecdeb9 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -4987,7 +4987,7 @@ static void tcp_check_space(struct sock *sk)
 	if (sock_flag(sk, SOCK_QUEUE_SHRUNK)) {
 		sock_reset_flag(sk, SOCK_QUEUE_SHRUNK);
 		/* pairs with tcp_poll() */
-		smp_mb__after_atomic();
+		smp_mb();
 		if (sk->sk_socket &&
 		    test_bit(SOCK_NOSPACE, &sk->sk_socket->flags))
 			tcp_new_space(sk);
-- 
2.6.1