From: Ben Hutchings <ben@decadent.org.uk>
Date: Sat, 26 Jun 2010 11:37:47 +0000 (+0000)
Subject: ipv6: Clamp reported valid_lft to a minimum of 0
X-Git-Tag: v2.6.36-rc1~571^2~407
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f56619fc72407561b00c52244a2caa53d730bc4a;p=profile%2Fivi%2Fkernel-adaptation-intel-automotive.git

ipv6: Clamp reported valid_lft to a minimum of 0

Since addresses are only revalidated every 2 minutes, the reported
valid_lft can underflow shortly before the address is deleted.
Clamp it to a minimum of 0, as for prefered_lft.

Reported-by: Piotr Lewandowski <piotr.lewandowski@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index c20a7c2..51a273f 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3495,8 +3495,12 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
 				preferred -= tval;
 			else
 				preferred = 0;
-			if (valid != INFINITY_LIFE_TIME)
-				valid -= tval;
+			if (valid != INFINITY_LIFE_TIME) {
+				if (valid > tval)
+					valid -= tval;
+				else
+					valid = 0;
+			}
 		}
 	} else {
 		preferred = INFINITY_LIFE_TIME;