v3.8-rc3: uninitialized warnings in net/netfilter/xt_CT.c

v3.8-rc3: uninitialized warnings in net/netfilter/xt_CT.c

[Borislav Petkov]

Hi,

I get

net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v1’:
net/netfilter/xt_CT.c:250:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v0’:
net/netfilter/xt_CT.c:112:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

when building 3.8-rc3 here.

And this time, the warnings are real:

static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
{
	struct xt_ct_target_info *info = par->targinfo;
	struct nf_conntrack_tuple t;
	struct nf_conn *ct;
	int ret;

	if (info->flags & ~XT_CT_NOTRACK)
		return -EINVAL;

	if (info->flags & XT_CT_NOTRACK) {
		ct = nf_ct_untracked_get();
		atomic_inc(&ct->ct_general.use);
		goto out;
	}

#ifndef CONFIG_NF_CONNTRACK_ZONES
	if (info->zone)
		goto err1;
#endif
...

ret doesn't get initialized and if the first two if-blocks are false and
CONFIG_NF_CONNTRACK_ZONES is not defined (as is in my case) we do "goto
err1":

err1:
        return ret;

which returns an uninitialized 'ret'.

Now, I don't know the code to know whether if (info->zone) is ever true
but someone better check this before subtle bugs start happening.

Ditto for the xt_ct_tg_check_v1() function.

Thanks.

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--

Re: v3.8-rc3: uninitialized warnings in net/netfilter/xt_CT.c

[Pablo Neira Ayuso]

[-- Attachment #1: Type: text/plain, Size: 496 bytes --]

Hi Borislav,

On Thu, Jan 10, 2013 at 12:18:21PM +0100, Borislav Petkov wrote:
> Hi,
> 
> I get
> 
> net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v1’:
> net/netfilter/xt_CT.c:250:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v0’:
> net/netfilter/xt_CT.c:112:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Patch attached to address this issue.

[-- Attachment #2: 0001-netfilter-xt_CT-fix-unset-return-value-if-conntrack-.patch --]
[-- Type: text/x-diff, Size: 1596 bytes --]

>From 3ceaa3b1baa660aaeef63b86ea9771dcab6d0acd Mon Sep 17 00:00:00 2001
From: Pablo Neira Ayuso <pablo@netfilter.org>
Date: Thu, 10 Jan 2013 12:42:15 +0100
Subject: [PATCH] netfilter: xt_CT: fix unset return value if conntrack zone
 are disabled
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v1’:
net/netfilter/xt_CT.c:250:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v0’:
net/netfilter/xt_CT.c:112:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Reported-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
---
 net/netfilter/xt_CT.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/xt_CT.c b/net/netfilter/xt_CT.c
index 2a08430..bde009e 100644
--- a/net/netfilter/xt_CT.c
+++ b/net/netfilter/xt_CT.c
@@ -109,7 +109,7 @@ static int xt_ct_tg_check_v0(const struct xt_tgchk_param *par)
 	struct xt_ct_target_info *info = par->targinfo;
 	struct nf_conntrack_tuple t;
 	struct nf_conn *ct;
-	int ret;
+	int ret = -EOPNOTSUPP;
 
 	if (info->flags & ~XT_CT_NOTRACK)
 		return -EINVAL;
@@ -247,7 +247,7 @@ static int xt_ct_tg_check_v1(const struct xt_tgchk_param *par)
 	struct xt_ct_target_info_v1 *info = par->targinfo;
 	struct nf_conntrack_tuple t;
 	struct nf_conn *ct;
-	int ret;
+	int ret = -EOPNOTSUPP;
 
 	if (info->flags & ~XT_CT_NOTRACK)
 		return -EINVAL;
-- 
1.7.10.4

Re: v3.8-rc3: uninitialized warnings in net/netfilter/xt_CT.c

[Borislav Petkov]

On Thu, Jan 10, 2013 at 12:47:42PM +0100, Pablo Neira Ayuso wrote:
> Patch attached to address this issue.

> From 3ceaa3b1baa660aaeef63b86ea9771dcab6d0acd Mon Sep 17 00:00:00 2001
> From: Pablo Neira Ayuso <pablo@netfilter.org>
> Date: Thu, 10 Jan 2013 12:42:15 +0100
> Subject: [PATCH] netfilter: xt_CT: fix unset return value if conntrack zone
>  are disabled
> MIME-Version: 1.0
> Content-Type: text/plain; charset=UTF-8
> Content-Transfer-Encoding: 8bit
> 
> net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v1’:
> net/netfilter/xt_CT.c:250:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v0’:
> net/netfilter/xt_CT.c:112:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> 
> Reported-by: Borislav Petkov <bp@alien8.de>
> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Yep, that's exactly what I meant, thanks Pablo.

Acked-by: Borislav Petkov <bp@alien8.de>

-- 
Regards/Gruss,
    Boris.

Sent from a fat crate under my desk. Formatting is fine.
--

Re: v3.8-rc3: uninitialized warnings in net/netfilter/xt_CT.c

[Pablo Neira Ayuso]

On Thu, Jan 10, 2013 at 01:01:21PM +0100, Borislav Petkov wrote:
> On Thu, Jan 10, 2013 at 12:47:42PM +0100, Pablo Neira Ayuso wrote:
> > Patch attached to address this issue.
> 
> > From 3ceaa3b1baa660aaeef63b86ea9771dcab6d0acd Mon Sep 17 00:00:00 2001
> > From: Pablo Neira Ayuso <pablo@netfilter.org>
> > Date: Thu, 10 Jan 2013 12:42:15 +0100
> > Subject: [PATCH] netfilter: xt_CT: fix unset return value if conntrack zone
> >  are disabled
> > MIME-Version: 1.0
> > Content-Type: text/plain; charset=UTF-8
> > Content-Transfer-Encoding: 8bit
> > 
> > net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v1’:
> > net/netfilter/xt_CT.c:250:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> > net/netfilter/xt_CT.c: In function ‘xt_ct_tg_check_v0’:
> > net/netfilter/xt_CT.c:112:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]
> > 
> > Reported-by: Borislav Petkov <bp@alien8.de>
> > Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
> 
> Yep, that's exactly what I meant, thanks Pablo.
> 
> Acked-by: Borislav Petkov <bp@alien8.de>

Applied, thanks Borislav.
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