ipv6: release rt6->rt6i_idev properly during ifdown

When a dst is created by addrconf_dst_alloc() for a host route or an anycast route, dst->dev points to loopback dev while rt6->rt6i_idev points to a real device. When the real device goes down, the current cleanup code only checks for dst->dev and assumes rt6->rt6i_idev->dev is the same. This causes the refcount leak on the real device in the above situation. This patch makes sure to always release the refcount taken on rt6->rt6i_idev during dst_dev_put(). Fixes: 587fea7 ("ipv6: mark DST_NOGC and remove the operation of dst_free()") Reported-by: John Stultz <[email protected]> Tested-by: John Stultz <[email protected]> Tested-by: Martin KaFai Lau <[email protected]> Signed-off-by: Wei Wang <[email protected]> Signed-off-by: Martin KaFai Lau <[email protected]> Acked-by: David Ahern <[email protected]> Signed-off-by: David S. Miller <[email protected]>
octaviansoldea · Aug 15, 2017 · e5645f5 · e5645f5
1 parent 36f41f8
commit e5645f5
Showing 1 changed file with 5 additions and 8 deletions.
diff --git a/net/ipv6/route.c b/net/ipv6/route.c
@@ -417,14 +417,11 @@ static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
 	struct net_device *loopback_dev =
 		dev_net(dev)->loopback_dev;
 
-	if (dev != loopback_dev) {
-		if (idev && idev->dev == dev) {
-			struct inet6_dev *loopback_idev =
-				in6_dev_get(loopback_dev);
-			if (loopback_idev) {
-				rt->rt6i_idev = loopback_idev;
-				in6_dev_put(idev);
-			}
+	if (idev && idev->dev != loopback_dev) {
+		struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
+		if (loopback_idev) {
+			rt->rt6i_idev = loopback_idev;
+			in6_dev_put(idev);
 		}
 	}
 }