From e5645f51ba99738b0e5d708edf9c6454f33b9310 Mon Sep 17 00:00:00 2001 From: Wei Wang Date: Mon, 14 Aug 2017 10:44:59 -0700 Subject: [PATCH] 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: 587fea741134 ("ipv6: mark DST_NOGC and remove the operation of dst_free()") Reported-by: John Stultz Tested-by: John Stultz Tested-by: Martin KaFai Lau Signed-off-by: Wei Wang Signed-off-by: Martin KaFai Lau Acked-by: David Ahern Signed-off-by: David S. Miller --- net/ipv6/route.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index a640fbcba15dbf..99d4727f2b1863 100644 --- 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); } } }