From: Arnd Bergmann <arnd@arndb.de>
To: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
netdev@vger.kernel.org, Arnd Bergmann <arnd@arndb.de>,
Patrick McHardy <kaber@trash.net>,
Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>,
"David S. Miller" <davem@davemloft.net>,
Florian Westphal <fw@strlen.de>,
Eric Dumazet <edumazet@google.com>,
linux-kernel@vger.kernel.org
Subject: [PATCH 2/2] [nf-next] netfilter: fix NF_REPEAT handling
Date: Tue, 8 Nov 2016 14:28:19 +0100 [thread overview]
Message-ID: <20161108132914.1495283-2-arnd@arndb.de> (raw)
In-Reply-To: <20161108132914.1495283-1-arnd@arndb.de>
gcc correctly identified a theoretical uninitialized variable use:
net/netfilter/nf_conntrack_core.c: In function 'nf_conntrack_in':
net/netfilter/nf_conntrack_core.c:1125:14: error: 'l4proto' may be used uninitialized in this function [-Werror=maybe-uninitialized]
This could only happen when we 'goto out' before looking up l4proto,
and then enter the retry, implying that l3proto->get_l4proto()
returned NF_REPEAT. This does not currently get returned in any
code path and probably won't ever happen, but is not good to
rely on.
Moving the repeat handling up a little should have the same
behavior as today but avoids the warning by making that case
impossible to enter.
Fixes: 08733a0cb7de ("netfilter: handle NF_REPEAT from nf_conntrack_in()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
The patch causing this is currently only in nf-next, and not yet
in net-next.
---
net/netfilter/nf_conntrack_core.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index de4b8a75f30b..610c9de0ce18 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -1337,6 +1337,8 @@ nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
NF_CT_STAT_INC_ATOMIC(net, invalid);
if (ret == -NF_DROP)
NF_CT_STAT_INC_ATOMIC(net, drop);
+ if (ret == -NF_REPEAT && tmpl)
+ goto repeat;
ret = -ret;
goto out;
}
@@ -1349,10 +1351,7 @@ nf_conntrack_in(struct net *net, u_int8_t pf, unsigned int hooknum,
* closed/aborted connection. We have to go back and create a
* fresh conntrack.
*/
- if (ret == NF_REPEAT)
- goto repeat;
- else
- nf_ct_put(tmpl);
+ nf_ct_put(tmpl);
}
return ret;
--
2.9.0
next prev parent reply other threads:[~2016-11-08 13:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-08 13:28 [PATCH 1/2] [net-next] udp: provide udp{4,6}_lib_lookup for nf_socket_ipv{4,6} Arnd Bergmann
2016-11-08 13:28 ` Arnd Bergmann [this message]
2016-11-09 23:15 ` [PATCH 2/2] [nf-next] netfilter: fix NF_REPEAT handling Pablo Neira Ayuso
2016-11-09 23:08 ` [PATCH 1/2] [net-next] udp: provide udp{4,6}_lib_lookup for nf_socket_ipv{4,6} Pablo Neira Ayuso
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