Going forward skb_dst_set will assert that skb dst_entry
is empty during skb_dst_set. skb_dstref_steal is added to reset
existing entry without doing refcnt. Switch to skb_dstref_steal
in __xfrm_route_forward and add a comment on why it's safe
to skip skb_dstref_restore.
Signed-off-by: Stanislav Fomichev <sdf@xxxxxxxxxxx>
---
net/xfrm/xfrm_policy.c | 10 ++++++++--
1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c
index c5035a9bc3bb..7111184eef59 100644
--- a/net/xfrm/xfrm_policy.c
+++ b/net/xfrm/xfrm_policy.c
@@ -3881,12 +3881,18 @@ int __xfrm_route_forward(struct sk_buff *skb, unsigned short family)
}
skb_dst_force(skb);
- if (!skb_dst(skb)) {
+ dst = skb_dst(skb);
+ if (!dst) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMFWDHDRERROR);
return 0;
}
- dst = xfrm_lookup(net, skb_dst(skb), &fl, NULL, XFRM_LOOKUP_QUEUE);
+ /* ignore return value from skb_dstref_steal, xfrm_lookup takes
+ * care of dropping the refcnt if needed.
+ */
+ skb_dstref_steal(skb);
+
+ dst = xfrm_lookup(net, dst, &fl, NULL, XFRM_LOOKUP_QUEUE);
if (IS_ERR(dst)) {
res = 0;
dst = NULL;
--
2.50.1
