From: Steffen Klassert <steffen.klassert@secunet.com>
Date: Fri, 4 Jun 2010 01:57:38 +0000 (+0000)
Subject: net: check for refcount if pop a stacked dst_entry
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=8764ab2ca7ab5055e1ca80f9cfa4970c34acb804;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

net: check for refcount if pop a stacked dst_entry

xfrm triggers a warning if dst_pop() drops a refcount
on a noref dst. This patch changes dst_pop() to
skb_dst_pop(). skb_dst_pop() drops the refcnt only
on a refcounted dst. Also we don't clone the child
dst_entry, so it is not refcounted and we can use
skb_dst_set_noref() in xfrm_output_one().

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/include/net/dst.h b/include/net/dst.h
index 612069beda73..81d1413a8701 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -250,11 +250,11 @@ static inline void skb_tunnel_rx(struct sk_buff *skb, struct net_device *dev)
  * Linux networking.  Thus, destinations are stackable.
  */
 
-static inline struct dst_entry *dst_pop(struct dst_entry *dst)
+static inline struct dst_entry *skb_dst_pop(struct sk_buff *skb)
 {
-	struct dst_entry *child = dst_clone(dst->child);
+	struct dst_entry *child = skb_dst(skb)->child;
 
-	dst_release(dst);
+	skb_dst_drop(skb);
 	return child;
 }
 
diff --git a/net/xfrm/xfrm_output.c b/net/xfrm/xfrm_output.c
index 6a329158bdfa..a3cca0a94346 100644
--- a/net/xfrm/xfrm_output.c
+++ b/net/xfrm/xfrm_output.c
@@ -95,13 +95,13 @@ resume:
 			goto error_nolock;
 		}
 
-		dst = dst_pop(dst);
+		dst = skb_dst_pop(skb);
 		if (!dst) {
 			XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTERROR);
 			err = -EHOSTUNREACH;
 			goto error_nolock;
 		}
-		skb_dst_set(skb, dst);
+		skb_dst_set_noref(skb, dst);
 		x = dst->xfrm;
 	} while (x && !(x->outer_mode->flags & XFRM_MODE_FLAG_TUNNEL));