From: t_jeang <devnull@localhost>
Date: Tue, 6 Jan 2009 12:06:02 +0000 (+0000)
Subject: It is possible for a frontend to generate a TSO request which doesn't
X-Git-Tag: netback-dont-get-stuck-in-state-closed
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=d8edb5e424bb8555eb66446be9f842d3aed3b95e;p=xenclient%2Fkernel.git

It is possible for a frontend to generate a TSO request which doesn't
actually need segmentation (i.e. with size < MTU).  Make sure this
doesn't crash the backend.
---

diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index f8c5cff9..33bd270c 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -2214,7 +2214,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
 	th = skb->h.th;
 	seq = ntohl(th->seq);
 
-	do {
+	while (skb->next) {
 		th->fin = th->psh = 0;
 
 		th->check = ~csum_fold(th->check + delta);
@@ -2228,7 +2228,7 @@ struct sk_buff *tcp_tso_segment(struct sk_buff *skb, int features)
 
 		th->seq = htonl(seq);
 		th->cwr = 0;
-	} while (skb->next);
+	}
 
 	delta = htonl(oldlen + (skb->tail - skb->h.raw) + skb->data_len);
 	th->check = ~csum_fold(th->check + delta);