From: Phil Oester <kernel@linuxace.com>
To: netdev@vger.kernel.org, netfilter-devel@vger.kernel.org
Cc: edumazet@google.com
Subject: Netfilter owner match breakage
Date: Tue, 27 Aug 2013 13:24:45 -0700 [thread overview]
Message-ID: <20130827202445.GA3114@linuxace.com> (raw)
In commit 90ba9b19 (tcp: tcp_make_synack() can use alloc_skb()), Eric changed
the call to sock_wmalloc in tcp_make_synack to alloc_skb. In doing so,
the netfilter owner match lost its ability to block the SYNACK packet on
outbound listening sockets. For example:
[phil@f19_main ~]$ id
uid=1000(phil) gid=1000(phil) groups=1000(phil)
[phil@f19_main ~]$ sudo iptables -A OUTPUT -p tcp -m owner --uid-owner 1000 -j REJECT
[phil@f19_main ~]$ echo hi | nc -l -p 8888
Before this commit, attempting to connect to the port 8888 listener generated
this:
10.10.10.1.47457 > 10.10.10.110.8888: Flags [S], seq 1855270582 [...]
10.10.10.110 > 10.10.10.110: ICMP 10.10.10.1 tcp port 47457 unreachable, length 68
After this commit, the session is established but the first packet of the
session gets rejected:
10.10.10.1.47453 > 10.10.10.110.8888: Flags [S], seq 2089355862 [...]
10.10.10.110.8888 > 10.10.10.1.47453: Flags [S.], seq 2554257713, ack 2089355863 [...]
10.10.10.1.47453 > 10.10.10.110.8888: Flags [.], ack 1, win 115 [...]
10.10.10.110 > 10.10.10.110: ICMP 10.10.10.1 tcp port 47453 unreachable, length 63
Reverting 90ba9b19 (and adjusting for the removal of s_data_desired) fixes the
problem. Is there a better way to do this?
Phil
next reply other threads:[~2013-08-27 20:24 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-08-27 20:24 Phil Oester [this message]
2013-08-27 20:43 ` Netfilter owner match breakage Eric Dumazet
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