netdev - [PATCH net] net: xfrm: don't double-hold dst when sk

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Date:   Wed, 23 Aug 2017 17:14:39 +0900
From:   Lorenzo Colitti <lorenzo@...gle.com>
To:     netdev@...r.kernel.org
Cc:     weiwan@...gle.com, davem@...emloft.net,
        steffen.klassert@...unet.com, misterikkit@...ogle.com,
        Lorenzo Colitti <lorenzo@...gle.com>
Subject: [PATCH net] net: xfrm: don't double-hold dst when sk_policy in use.

While removing dst_entry garbage collection, commit 52df157f17e5
("xfrm: take refcnt of dst when creating struct xfrm_dst bundle")
changed xfrm_resolve_and_create_bundle so it returns an xdst with
a refcount of 1 instead of 0.

However, it did not delete the dst_hold performed by xfrm_lookup
when a per-socket policy is in use. This means that when a
socket policy is in use, dst entries returned by xfrm_lookup have
a refcount of 2, and are not freed when no longer in use.

Cc: Wei Wang <weiwan@...gle.com>
Fixes: 52df157f17 ("xfrm: take refcnt of dst when creating struct xfrm_dst bundle")
Tested: https://android-review.googlesource.com/417481
Tested: https://android-review.googlesource.com/418659
Tested: https://android-review.googlesource.com/424463
Tested: https://android-review.googlesource.com/452776 passes on net-next
Signed-off-by: Lorenzo Colitti <lorenzo@...gle.com>
---
 net/xfrm/xfrm_policy.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index 6f5a0dad50..69b16ee327 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -2226,7 +2226,6 @@ struct dst_entry *xfrm_lookup(struct net *net, struct dst_entry *dst_orig,
 				goto no_transform;
 			}
 
-			dst_hold(&xdst->u.dst);
 			route = xdst->route;
 		}
 	}
-- 
2.14.1.480.gb18f417b89-goog