[PATCH 3.12 062/176] net: Reset secmark when scrubbing packet

From: Thomas Graf <tgraf@suug.ch>

3.12-stable review patch.  If anyone has any objections, please let me know.

===============

[ Upstream commit b8fb4e0648a2ab3734140342002f68fb0c7d1602 ]

skb_scrub_packet() is called when a packet switches between a context
such as between underlay and overlay, between namespaces, or between
L3 subnets.

While we already scrub the packet mark, connection tracking entry,
and cached destination, the security mark/context is left intact.

It seems wrong to inherit the security context of a packet when going
from overlay to underlay or across forwarding paths.

Signed-off-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Flavio Leitner <redacted>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jiri Slaby <redacted>
---
 net/core/skbuff.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index a8cf33868f9c..17313d17a923 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c

@@ -3523,6 +3523,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 	skb->local_df = 0;
 	skb_dst_drop(skb);
 	skb->mark = 0;
+	skb_init_secmark(skb);
 	secpath_reset(skb);
 	nf_reset(skb);
 	nf_reset_trace(skb);

-- 
2.2.2