ipv6: avoid wraparound for expired preferred lifetime
Avoid showing wrong high values when the preferred lifetime of an address
is expired.
Signed-off-by: Jens Rosenboom <me@jayr.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8c1e86a..3883b40 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -3362,7 +3362,10 @@
valid = ifa->valid_lft;
if (preferred != INFINITY_LIFE_TIME) {
long tval = (jiffies - ifa->tstamp)/HZ;
- preferred -= tval;
+ if (preferred > tval)
+ preferred -= tval;
+ else
+ preferred = 0;
if (valid != INFINITY_LIFE_TIME)
valid -= tval;
}