From a3264435b4ca1ccee54cbef2970f2ba4bef39e2d Mon Sep 17 00:00:00 2001
From: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Date: Mon, 19 May 2008 16:54:29 -0700
Subject: [PATCH] ipv6 addrconf: Fix route lifetime setting in corner case.
Because of arithmetic overflow avoidance, the actual lifetime setting
(vs the value given by RA) did not increase monotonically around
0x7fffffff/HZ.
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
net/ipv6/route.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 12bba0880345..98aa50c11dd6 100644
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -475,7 +475,7 @@ int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
lifetime = ntohl(rinfo->lifetime);
if (lifetime == 0xffffffff) {
/* infinity */
- } else if (lifetime > 0x7fffffff/HZ) {
+ } else if (lifetime > 0x7fffffff/HZ - 1) {
/* Avoid arithmetic overflow */
lifetime = 0x7fffffff/HZ - 1;
}
--
GitLab