Merge branch 'net-ipv4-remove-erroneous-advancement-of-list-pointer'

Florian Westphal says:

====================
net: ipv4: remove erroneous advancement of list pointer

Tariq reported a soft lockup on net-next that Mellanox was able to
bisect to 2638eb8b ("net: ipv4: provide __rcu annotation for ifa_list").

While reviewing above patch I found a regression when addresses have a
lifetime specified.

Second patch extends rtnetlink.sh to trigger crash
(without first patch applied).
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/devinet.c

@@ -745,8 +745,7 @@ static void check_lifetime(struct work_struct *work)
 				ifap = &ifa->ifa_dev->ifa_list;
 				tmp = rtnl_dereference(*ifap);
 				while (tmp) {
-					tmp = rtnl_dereference(tmp->ifa_next);
-					if (rtnl_dereference(*ifap) == ifa) {
+					if (tmp == ifa) {
 						inet_del_ifa(ifa->ifa_dev,
 							     ifap, 1);
 						break;

tools/testing/selftests/net/rtnetlink.sh

@@ -249,6 +249,26 @@ kci_test_route_get()
 	echo "PASS: route get"
 }
 
+kci_test_addrlft()
+{
+	for i in $(seq 10 100) ;do
+		lft=$(((RANDOM%3) + 1))
+		ip addr add 10.23.11.$i/32 dev "$devdummy" preferred_lft $lft valid_lft $((lft+1))
+		check_err $?
+	done
+
+	sleep 5
+
+	ip addr show dev "$devdummy" | grep "10.23.11."
+	if [ $? -eq 0 ]; then
+		echo "FAIL: preferred_lft addresses remaining"
+		check_err 1
+		return
+	fi
+
+	echo "PASS: preferred_lft addresses have expired"
+}
+
 kci_test_addrlabel()
 {
 	ret=0
@@ -1140,6 +1160,7 @@ kci_test_rtnl()
 
 	kci_test_polrouting
 	kci_test_route_get
+	kci_test_addrlft
 	kci_test_tc
 	kci_test_gre
 	kci_test_gretap