Commit e5645f51 authored Aug 14, 2017 by Wei Wang Committed by David S. Miller Aug 14, 2017

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: 587fea74 ("ipv6: mark DST_NOGC and remove the operation of
dst_free()")
Reported-by: John Stultz <john.stultz@linaro.org>
Tested-by: John Stultz <john.stultz@linaro.org>
Tested-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Wei Wang <weiwan@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 36f41f8f

net/ipv6/route.c

+5 −8

Original line number	Diff line number	Diff line
		@@ -417,17 +417,14 @@ 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 (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);
		}
		}
		}
		}

		static bool __rt6_check_expired(const struct rt6_info *rt)
		{

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