netdev - [PATCH 8/8] netfilter: xt_conntrack: fix inverted conntrack direction test

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

Date:	Tue,  5 Apr 2011 15:04:19 +0200
From:	kaber@...sh.net
To:	davem@...emloft.net
Cc:	netfilter-devel@...r.kernel.org, netdev@...r.kernel.org
Subject: [PATCH 8/8] netfilter: xt_conntrack: fix inverted conntrack direction test

From: Florian Westphal <fw@...len.de>

--ctdir ORIGINAL matches REPLY packets, and vv:

userspace sets "invert_flags &= ~XT_CONNTRACK_DIRECTION" in ORIGINAL
case.

Thus: (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
      !!(info->invert_flags & XT_CONNTRACK_DIRECTION))

yields "1 ^ 0", which is true -> returns false.

Reproducer:
iptables -I OUTPUT 1 -p tcp --syn -m conntrack --ctdir ORIGINAL

Signed-off-by: Florian Westphal <fwestphal@...aro.com>
Signed-off-by: Patrick McHardy <kaber@...sh.net>
---
 net/netfilter/xt_conntrack.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/net/netfilter/xt_conntrack.c b/net/netfilter/xt_conntrack.c
index 2c0086a..481a86f 100644
--- a/net/netfilter/xt_conntrack.c
+++ b/net/netfilter/xt_conntrack.c
@@ -195,7 +195,7 @@ conntrack_mt(const struct sk_buff *skb, struct xt_action_param *par,
 		return info->match_flags & XT_CONNTRACK_STATE;
 	if ((info->match_flags & XT_CONNTRACK_DIRECTION) &&
 	    (CTINFO2DIR(ctinfo) == IP_CT_DIR_ORIGINAL) ^
-	    !!(info->invert_flags & XT_CONNTRACK_DIRECTION))
+	    !(info->invert_flags & XT_CONNTRACK_DIRECTION))
 		return false;
 
 	if (info->match_flags & XT_CONNTRACK_ORIGSRC)
-- 
1.7.2.3

--
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