[PATCH 3.16.y-ckt 065/126] net: Reset secmark when scrubbing packet

[Luis Henriques]

3.16.7-ckt5 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Thomas Graf <tgraf at suug.ch>

commit b8fb4e0648a2ab3734140342002f68fb0c7d1602 upstream.

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 at suug.ch>
Acked-by: Flavio Leitner <fbl at sysclose.org>
Signed-off-by: David S. Miller <davem at davemloft.net>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 net/core/skbuff.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index f5f14d54d6a2..fe07faaed256 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3933,6 +3933,7 @@ void skb_scrub_packet(struct sk_buff *skb, bool xnet)
 	skb->ignore_df = 0;
 	skb_dst_drop(skb);
 	skb->mark = 0;
+	skb_init_secmark(skb);
 	secpath_reset(skb);
 	nf_reset(skb);
 	nf_reset_trace(skb);
-- 
2.1.4