1 files changed, 31 insertions, 4 deletions

diff --git a/net/ipv6/addrconf.c b/net/ipv6/addrconf.c
index 8c1e86afbbf5..43b3c9f89c12 100644
--- a/net/ipv6/addrconf.c
+++ b/net/ipv6/addrconf.c
@@ -1916,8 +1916,32 @@ ok:
 					update_lft = 1;
 				else if (stored_lft <= MIN_VALID_LIFETIME) {
 					/* valid_lft <= stored_lft is always true */
-					/* XXX: IPsec */
-					update_lft = 0;
+					/*
+					 * RFC 4862 Section 5.5.3e:
+					 * "Note that the preferred lifetime of
+					 *  the corresponding address is always
+					 *  reset to the Preferred Lifetime in
+					 *  the received Prefix Information
+					 *  option, regardless of whether the
+					 *  valid lifetime is also reset or
+					 *  ignored."
+					 *
+					 *  So if the preferred lifetime in
+					 *  this advertisement is different
+					 *  than what we have stored, but the
+					 *  valid lifetime is invalid, just
+					 *  reset prefered_lft.
+					 *
+					 *  We must set the valid lifetime
+					 *  to the stored lifetime since we'll
+					 *  be updating the timestamp below,
+					 *  else we'll set it back to the
+					 *  minumum.
+					 */
+					if (prefered_lft != ifp->prefered_lft) {
+						valid_lft = stored_lft;
+						update_lft = 1;
+					}
 				} else {
 					valid_lft = MIN_VALID_LIFETIME;
 					if (valid_lft < prefered_lft)
@@ -3085,7 +3109,7 @@ restart:
 				spin_unlock(&ifp->lock);
 				continue;
 			} else if (age >= ifp->prefered_lft) {
-				/* jiffies - ifp->tsamp > age >= ifp->prefered_lft */
+				/* jiffies - ifp->tstamp > age >= ifp->prefered_lft */
 				int deprecate = 0;
 
 				if (!(ifp->flags&IFA_F_DEPRECATED)) {
@@ -3362,7 +3386,10 @@ static int inet6_fill_ifaddr(struct sk_buff *skb, struct inet6_ifaddr *ifa,
 		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;
 		}