diff mbox

[net-next] tcp/dccp: fix potential NULL deref in __inet_inherit_port()

Message ID 1444827518.4166.27.camel@edumazet-glaptop2.roam.corp.google.com
State Accepted, archived
Delegated to: David Miller
Headers show

Commit Message

Eric Dumazet Oct. 14, 2015, 12:58 p.m. UTC 
From: Eric Dumazet <edumazet@google.com>

As we no longer hold listener lock in fast path, it is possible that a
child is created right after listener freed its bound port, if a close()
is done while incoming packets are processed.

__inet_inherit_port() must detect this and return an error,
so that caller can free the child earlier.

Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
---
 net/ipv4/inet_hashtables.c |    4 ++++
 1 file changed, 4 insertions(+)



--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Comments

David Miller Oct. 15, 2015, 2:08 a.m. UTC | #1 
From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Wed, 14 Oct 2015 05:58:38 -0700

> From: Eric Dumazet <edumazet@google.com>
> 
> As we no longer hold listener lock in fast path, it is possible that a
> child is created right after listener freed its bound port, if a close()
> is done while incoming packets are processed.
> 
> __inet_inherit_port() must detect this and return an error,
> so that caller can free the child earlier.
> 
> Fixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
> Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
> Signed-off-by: Eric Dumazet <edumazet@google.com>

Applied.
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/net/ipv4/inet_hashtables.c b/net/ipv4/inet_hashtables.c
index 08643a3616af..958728a22001 100644
--- a/net/ipv4/inet_hashtables.c
+++ b/net/ipv4/inet_hashtables.c
@@ -137,6 +137,10 @@  int __inet_inherit_port(const struct sock *sk, struct sock *child)
 
 	spin_lock(&head->lock);
 	tb = inet_csk(sk)->icsk_bind_hash;
+	if (unlikely(!tb)) {
+		spin_unlock(&head->lock);
+		return -ENOENT;
+	}
 	if (tb->port != port) {
 		/* NOTE: using tproxy and redirecting skbs to a proxy
 		 * on a different listener port breaks the assumption