netdev - [Patch net-next] net: clear skb->priority when forwarding to another netns

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <1426886949-12447-1-git-send-email-xiyou.wangcong@gmail.com>
Date:	Fri, 20 Mar 2015 14:29:09 -0700
From:	Cong Wang <xiyou.wangcong@...il.com>
To:	netdev@...r.kernel.org
Cc:	Cong Wang <xiyou.wangcong@...il.com>
Subject: [Patch net-next] net: clear skb->priority when forwarding to another netns

skb->priority can be set for two purposes:

1) With respect to IP TOS field, which is computed by a mask.
Ususally used for priority qdisc's (pfifo, prio etc.), on TX
side (we only have ingress qdisc on RX side).

2) Used as a classid or flowid, works in the same way with tc
classid. What's more, this can even override the classid
of tc filters.

For case 1), it has been respected within its netns, I don't
see any point of keeping it for another netns, especially
when packets will be forwarded to Rx path (no matter from TX
path or RX path).

For case 2) we care, our applications run inside a netns,
and we classify the packets by our own filters outside,
If some application sets this priority, it could bypass
our filters, therefore clear it when moving out of a netns,
it makes no sense to bypass tc filters out of its netns.

Signed-off-by: Cong Wang <xiyou.wangcong@...il.com>
---
 net/core/dev.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/core/dev.c b/net/core/dev.c
index 5d43e01..a0408d4 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -1696,6 +1696,7 @@ int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
 	}

 	skb_scrub_packet(skb, true);
+	skb->priority = 0;
 	skb->protocol = eth_type_trans(skb, dev);
 	skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);

-- 
1.8.3.1

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html