2016-03-17 10:42:14

by Dan Carpenter

Subject: [patch] openvswitch: using a bit shift as a mask

The original condition is never true. We want to test if BIT(0) is set
but the code is ANDing with zero.

Fixes: 05752523e565 ('openvswitch: Interface with NAT.')
Signed-off-by: Dan Carpenter <[email protected]>

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index dc5eb29..29c82d6 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -668,7 +668,7 @@ static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
*/
if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
ct->status & IPS_NAT_MASK &&
- (!(ct->status & IPS_EXPECTED_BIT) || info->commit)) {
+ (!(ct->status & IPS_EXPECTED) || info->commit)) {
/* NAT an established or related connection like before. */
if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
/* This is the REPLY direction for a connection

2016-03-18 17:15:01

by Jarno Rajahalme

Subject: Re: [patch] openvswitch: using a bit shift as a mask

> On Mar 17, 2016, at 3:41 AM, Dan Carpenter <[email protected]> wrote:
>
> The original condition is never true. We want to test if BIT(0) is set
> but the code is ANDing with zero.
>
> Fixes: 05752523e565 ('openvswitch: Interface with NAT.')
> Signed-off-by: Dan Carpenter <[email protected]>
>
> diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
> index dc5eb29..29c82d6 100644
> --- a/net/openvswitch/conntrack.c
> +++ b/net/openvswitch/conntrack.c
> @@ -668,7 +668,7 @@ static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
> */
> if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
> ct->status & IPS_NAT_MASK &&
> - (!(ct->status & IPS_EXPECTED_BIT) || info->commit)) {
> + (!(ct->status & IPS_EXPECTED) || info->commit)) {
> /* NAT an established or related connection like before. */
> if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
> /* This is the REPLY direction for a connection

Thanks for spotting this! Maybe it would be even better to use the test_bit() function, like this:

> + (!test_bit(IPS_EXPECTED_BIT, &ct->status) || info->commit)) {


Jarno