releases/2.6.11.7/ipsec-icmp-deadlock.patch

From stable-bounces@linux.kernel.org  Sun Mar 20 07:59:10 2005
Date: Sun, 20 Mar 2005 16:58:50 +0100
From: Patrick McHardy <kaber@trash.net>
To: stable@kernel.org
Cc: 
Subject: [IPSEC]: Do not hold state lock while checking size

This patch from Herbert Xu fixes a deadlock with IPsec.
When an ICMP frag. required is sent and the ICMP message
needs the same SA as the packet that caused it the state
will be locked twice.

[IPSEC]: Do not hold state lock while checking size.

This can elicit ICMP message output and thus result in a
deadlock.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Chris Wright <chrisw@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff -Nru a/net/ipv4/xfrm4_output.c b/net/ipv4/xfrm4_output.c
--- a/net/ipv4/xfrm4_output.c	2005-03-20 16:53:05 +01:00
+++ b/net/ipv4/xfrm4_output.c	2005-03-20 16:53:05 +01:00
@@ -103,16 +103,16 @@
 			goto error_nolock;
 	}
 
-	spin_lock_bh(&x->lock);
-	err = xfrm_state_check(x, skb);
-	if (err)
-		goto error;
-
 	if (x->props.mode) {
 		err = xfrm4_tunnel_check_size(skb);
 		if (err)
-			goto error;
+			goto error_nolock;
 	}
+
+	spin_lock_bh(&x->lock);
+	err = xfrm_state_check(x, skb);
+	if (err)
+		goto error;
 
 	xfrm4_encap(skb);
 
diff -Nru a/net/ipv6/xfrm6_output.c b/net/ipv6/xfrm6_output.c
--- a/net/ipv6/xfrm6_output.c	2005-03-20 16:53:05 +01:00
+++ b/net/ipv6/xfrm6_output.c	2005-03-20 16:53:05 +01:00
@@ -103,16 +103,16 @@
 			goto error_nolock;
 	}
 
-	spin_lock_bh(&x->lock);
-	err = xfrm_state_check(x, skb);
-	if (err)
-		goto error;
-
 	if (x->props.mode) {
 		err = xfrm6_tunnel_check_size(skb);
 		if (err)
-			goto error;
+			goto error_nolock;
 	}
+
+	spin_lock_bh(&x->lock);
+	err = xfrm_state_check(x, skb);
+	if (err)
+		goto error;
 
 	xfrm6_encap(skb);