2019-05-01 13:43:16

by Colin King

Subject: [PATCH][next] openvswitch: check for null pointer return from nla_nest_start_noflag

From: Colin Ian King <[email protected]>

The call to nla_nest_start_noflag can return null in the unlikely
event that nla_put returns -EMSGSIZE. Check for this condition to
avoid a null pointer dereference on pointer nla_reply.

Addresses-Coverity: ("Dereference null return value")
Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
Signed-off-by: Colin Ian King <[email protected]>
---
net/openvswitch/conntrack.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
index c4128082f88b..333ec5f298fe 100644
--- a/net/openvswitch/conntrack.c
+++ b/net/openvswitch/conntrack.c
@@ -2175,6 +2175,10 @@ static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
return PTR_ERR(reply);

nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
+ if (!nla_reply) {
+ err = -EMSGSIZE;
+ goto exit_err;
+ }

if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
err = ovs_ct_limit_get_zone_limit(
--
2.20.1

2019-05-01 17:18:33

by Yi-Hung Wei

Subject: Re: [ovs-dev] [PATCH][next] openvswitch: check for null pointer return from nla_nest_start_noflag

On Wed, May 1, 2019 at 6:42 AM Colin King <[email protected]> wrote:
>
> From: Colin Ian King <[email protected]>
>
> The call to nla_nest_start_noflag can return null in the unlikely
> event that nla_put returns -EMSGSIZE. Check for this condition to
> avoid a null pointer dereference on pointer nla_reply.
>
> Addresses-Coverity: ("Dereference null return value")
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Signed-off-by: Colin Ian King <[email protected]>
> ---
> net/openvswitch/conntrack.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/net/openvswitch/conntrack.c b/net/openvswitch/conntrack.c
> index c4128082f88b..333ec5f298fe 100644
> --- a/net/openvswitch/conntrack.c
> +++ b/net/openvswitch/conntrack.c
> @@ -2175,6 +2175,10 @@ static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
> return PTR_ERR(reply);
>
> nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
> + if (!nla_reply) {
> + err = -EMSGSIZE;
> + goto exit_err;
> + }
>
> if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
> err = ovs_ct_limit_get_zone_limit(
> --
Thanks for the bug fix. Should it be on net rather than net-next?

Acked-by: Yi-Hung Wei <[email protected]>

2019-05-05 07:55:13

by David Miller

Subject: Re: [PATCH][next] openvswitch: check for null pointer return from nla_nest_start_noflag

From: Colin King <[email protected]>
Date: Wed, 1 May 2019 14:41:58 +0100

> From: Colin Ian King <[email protected]>
>
> The call to nla_nest_start_noflag can return null in the unlikely
> event that nla_put returns -EMSGSIZE. Check for this condition to
> avoid a null pointer dereference on pointer nla_reply.
>
> Addresses-Coverity: ("Dereference null return value")
> Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
> Signed-off-by: Colin Ian King <[email protected]>

Applied, thank you.