2019-06-19 12:55:23

by Arnd Bergmann

Subject: [PATCH] netfilter: synproxy: fix nf_synproxy_ipv{4,6}_init() return code

We return an uninitialized variable on success:

net/netfilter/nf_synproxy_core.c:793:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
if (snet->hook_ref4 == 0) {
^~~~~~~~~~~~~~~~~~~~

Initialize the return code to zero first.

Fixes: d7f9b2f18eae ("netfilter: synproxy: extract SYNPROXY infrastructure from {ipt, ip6t}_SYNPROXY")
Signed-off-by: Arnd Bergmann <[email protected]>
---
net/netfilter/nf_synproxy_core.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/netfilter/nf_synproxy_core.c b/net/netfilter/nf_synproxy_core.c
index 50677285f82e..283686e972a0 100644
--- a/net/netfilter/nf_synproxy_core.c
+++ b/net/netfilter/nf_synproxy_core.c
@@ -788,7 +788,7 @@ static const struct nf_hook_ops ipv4_synproxy_ops[] = {

int nf_synproxy_ipv4_init(struct synproxy_net *snet, struct net *net)
{
- int err;
+ int err = 0;

if (snet->hook_ref4 == 0) {
err = nf_register_net_hooks(net, ipv4_synproxy_ops,
@@ -1213,7 +1213,7 @@ static const struct nf_hook_ops ipv6_synproxy_ops[] = {
int
nf_synproxy_ipv6_init(struct synproxy_net *snet, struct net *net)
{
- int err;
+ int err = 0;

if (snet->hook_ref6 == 0) {
err = nf_register_net_hooks(net, ipv6_synproxy_ops,
--
2.20.0

2019-06-19 16:04:51

by Pablo Neira Ayuso

Subject: Re: [PATCH] netfilter: synproxy: fix nf_synproxy_ipv{4,6}_init() return code

On Wed, Jun 19, 2019 at 02:53:07PM +0200, Arnd Bergmann wrote:
> We return an uninitialized variable on success:
>
> net/netfilter/nf_synproxy_core.c:793:6: error: variable 'err' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
> if (snet->hook_ref4 == 0) {
> ^~~~~~~~~~~~~~~~~~~~
>
> Initialize the return code to zero first.

Thanks Arnd. We got a fix for this:

https://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf-next.git/commit/?id=72c5e11854afb842e157353be0291d65b91725f5