xfrm: release neighbor upon dst destruction

Neighbor is cloned in xfrm6_fill_dst but seems to never be released.
Neighbor entry should be released when XFRM6 dst entry is destroyed
in xfrm6_dst_destroy, otherwise references may be kept forever on
the device pointed by the neighbor entry.

I may not have understood all the subtleties of XFRM & dst so I would
be happy to receive comments on this patch.

Signed-off-by: Romain Kuntz <r.kuntz@ipflavors.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/ipv6/xfrm6_policy.c b/net/ipv6/xfrm6_policy.c
index c9844135c9ca..8f32718677bd 100644
--- a/net/ipv6/xfrm6_policy.c
+++ b/net/ipv6/xfrm6_policy.c
@@ -236,6 +236,8 @@ static void xfrm6_dst_destroy(struct dst_entry *dst)
 {
         struct xfrm_dst *xdst = (struct xfrm_dst *)dst;
 
+        if (likely(xdst->u.rt6.n))
+                neigh_release(xdst->u.rt6.n);
         if (likely(xdst->u.rt6.rt6i_idev))
                 in6_dev_put(xdst->u.rt6.rt6i_idev);
         dst_destroy_metrics_generic(dst);