netdev - [PATCH] Net: Don't send ICMP_FRAG

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-next>] [day] [month] [year] [list]

Date:	Fri, 28 Mar 2008 19:34:08 +1100
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	David Miller <davem@...emloft.net>
Cc:	netdev@...r.kernel.org, Herbert Xu <herbert@...dor.apana.org.au>,
	John Heffner <jheffner@....edu>
Subject: [PATCH] Net: Don't send ICMP_FRAG_NEEDED for GSO packets

Commit 9af3912ec9e30509b76cb376abb65a4d8af27df3 added a new check to
send ICMP fragmentation needed for large packets.

Unlike the check in ip_finish_output(), it doesn't check for GSO.  I
triggered this with the GSO TUN patches, so not sure if it needs to be
in 2.6.25 or not (do we otherwise forward GSO packets?).

Cc: John Heffner <jheffner@....edu>
Signed-off-by: Rusty Russell <rusty@...tcorp.com.au>

diff -r 69b8317ff51c net/ipv4/ip_forward.c
--- a/net/ipv4/ip_forward.c	Fri Mar 28 14:04:48 2008 +1100
+++ b/net/ipv4/ip_forward.c	Fri Mar 28 19:18:15 2008 +1100
@@ -85,7 +85,7 @@ int ip_forward(struct sk_buff *skb)
 	if (opt->is_strictroute && rt->rt_dst != rt->rt_gateway)
 		goto sr_failed;
 
-	if (unlikely(skb->len > dst_mtu(&rt->u.dst) &&
+	if (unlikely(skb->len > dst_mtu(&rt->u.dst) && !skb_is_gso(skb) &&
 		     (ip_hdr(skb)->frag_off & htons(IP_DF))) && !skb->local_df) {
 		IP_INC_STATS(IPSTATS_MIB_FRAGFAILS);
 		icmp_send(skb, ICMP_DEST_UNREACH, ICMP_FRAG_NEEDED,
--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html