[PATCH net 0/2] openvswitch tests for nla_nest_start

[PATCH net 0/2] openvswitch tests for nla_nest_start

[Stephen Hemminger]

Coverity is looking for bugs here, and a couple of new bugzilla
reports showed up where nla_nest_start return is not checked
for NULL.

Stephen Hemminger (2):
  openvswitch: check for null return for nla_nest_start
  openvswitch: check for null return for nla_nest_start in datapath

 net/openvswitch/conntrack.c | 2 ++
 net/openvswitch/datapath.c  | 8 ++++++++
 2 files changed, 10 insertions(+)

-- 
2.18.0

[PATCH net 1/2] openvswitch: check for null return for nla_nest_start

[Stephen Hemminger]

The call to nla_nest_start in conntrack can lead to a NULL
return so it's possible for attr to become NULL and we can potentially
get a NULL pointer dereference on attr.  Fix this by checking for
a NULL return.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200533
Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 net/openvswitch/conntrack.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index 284aca2a252d..2e316f641df8 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -2132,6 +2132,8 @@ static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
 		return PTR_ERR(reply);
 
 	nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
+	if (!nla_reply)
+		return PRT_ERR(-EMSGSIZE);
 
 	if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
 		err = ovs_ct_limit_get_zone_limit(
-- 
2.18.0

Re: [PATCH net 1/2] openvswitch: check for null return for nla_nest_start

[Pravin Shelar]

On Wed, Jul 18, 2018 at 9:12 AM, Stephen Hemminger
<stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org> wrote:
> The call to nla_nest_start in conntrack can lead to a NULL
> return so it's possible for attr to become NULL and we can potentially
> get a NULL pointer dereference on attr.  Fix this by checking for
> a NULL return.
>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200533
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Signed-off-by: Stephen Hemminger <stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org>
> ---
>  net/openvswitch/conntrack.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
> index 284aca2a252d..2e316f641df8 100644
> --- a/net/openvswitch/conntrack.c
> +++ b/net/openvswitch/conntrack.c
> @@ -2132,6 +2132,8 @@ static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
>                 return PTR_ERR(reply);
>
>         nla_reply = nla_nest_start(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
> +       if (!nla_reply)
> +               return PRT_ERR(-EMSGSIZE);
>
>         if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
>                 err = ovs_ct_limit_get_zone_limit(
> --
Acked-by: Pravin B Shelar <pshelar-LZ6Gd1LRuIk@public.gmane.org>

Thanks.

[PATCH net 2/2] openvswitch: check for null return for nla_nest_start in datapath

[Stephen Hemminger]

The call to nla_nest_start when forming packet messages can lead to a NULL
return so it's possible for attr to become NULL and we can potentially
get a NULL pointer dereference on attr.  Fix this by checking for
a NULL return.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200537
Fixes: 8f0aad6f35f7 ("openvswitch: Extend packet attribute for egress tunnel info")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
---
 net/openvswitch/datapath.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
index 0f5ce77460d4..93c3eb635827 100644
--- a/net/openvswitch/datapath.c
+++ b/net/openvswitch/datapath.c
@@ -460,6 +460,10 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 
 	if (upcall_info->egress_tun_info) {
 		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_EGRESS_TUN_KEY);
+		if (!nla) {
+			err = -EMSGSIZE;
+			goto out;
+		}
 		err = ovs_nla_put_tunnel_info(user_skb,
 					      upcall_info->egress_tun_info);
 		BUG_ON(err);
@@ -468,6 +472,10 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
 
 	if (upcall_info->actions_len) {
 		nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_ACTIONS);
+		if (!nla) {
+			err = -EMSGSIZE;
+			goto out;
+		}
 		err = ovs_nla_put_actions(upcall_info->actions,
 					  upcall_info->actions_len,
 					  user_skb);
-- 
2.18.0

Re: [PATCH net 2/2] openvswitch: check for null return for nla_nest_start in datapath

[Pravin Shelar]

On Wed, Jul 18, 2018 at 9:12 AM, Stephen Hemminger
<stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org> wrote:
> The call to nla_nest_start when forming packet messages can lead to a NULL
> return so it's possible for attr to become NULL and we can potentially
> get a NULL pointer dereference on attr.  Fix this by checking for
> a NULL return.
>
> Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200537
> Fixes: 8f0aad6f35f7 ("openvswitch: Extend packet attribute for egress tunnel info")
> Signed-off-by: Stephen Hemminger <stephen-OTpzqLSitTUnbdJkjeBofR2eb7JE58TQ@public.gmane.org>
> ---
>  net/openvswitch/datapath.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 0f5ce77460d4..93c3eb635827 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -460,6 +460,10 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>
>         if (upcall_info->egress_tun_info) {
>                 nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_EGRESS_TUN_KEY);
> +               if (!nla) {
> +                       err = -EMSGSIZE;
> +                       goto out;
> +               }
>                 err = ovs_nla_put_tunnel_info(user_skb,
>                                               upcall_info->egress_tun_info);
>                 BUG_ON(err);
> @@ -468,6 +472,10 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
>
>         if (upcall_info->actions_len) {
>                 nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_ACTIONS);
> +               if (!nla) {
> +                       err = -EMSGSIZE;
> +                       goto out;
> +               }
>                 err = ovs_nla_put_actions(upcall_info->actions,
>                                           upcall_info->actions_len,
>                                           user_skb);

Acked-by: Pravin B Shelar <pshelar-LZ6Gd1LRuIk@public.gmane.org>

Thanks.

Re: [PATCH net 0/2] openvswitch tests for nla_nest_start

[David Miller]

From: Stephen Hemminger <stephen@networkplumber.org>
Date: Wed, 18 Jul 2018 09:12:14 -0700

> Coverity is looking for bugs here, and a couple of new bugzilla
> reports showed up where nla_nest_start return is not checked
> for NULL.

Series applied and patch #2 queued up for -stable, thanks Stephen.

Re: [PATCH net 0/2] openvswitch tests for nla_nest_start

[David Miller]

From: David Miller <davem@davemloft.net>
Date: Fri, 20 Jul 2018 12:15:36 -0700 (PDT)

> From: Stephen Hemminger <stephen@networkplumber.org>
> Date: Wed, 18 Jul 2018 09:12:14 -0700
> 
>> Coverity is looking for bugs here, and a couple of new bugzilla
>> reports showed up where nla_nest_start return is not checked
>> for NULL.
> 
> Series applied and patch #2 queued up for -stable, thanks Stephen.

Actually, this wasn't compile tested and fails to build. :-/

Please fix this and resubmit.

Thanks.