On Sat, Apr 22, 2017 at 11:43 PM, Pan Bian <bianpan2...@163.com> wrote:
> Function nla_nest_start() will return a NULL pointer on error, and its
> return value should be validated before it is used. However, in function
> queue_userspace_packet(), its return value is ignored. This may result
> in NULL dereference when calling nla_nest_end(). This patch fixes the
> bug.
>
> Signed-off-by: Pan Bian <bianpan2...@163.com>
> ---
> net/openvswitch/datapath.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/net/openvswitch/datapath.c b/net/openvswitch/datapath.c
> index 9c62b63..34c0fbd 100644
> --- a/net/openvswitch/datapath.c
> +++ b/net/openvswitch/datapath.c
> @@ -489,7 +489,8 @@ static int queue_userspace_packet(struct datapath *dp,
> struct sk_buff *skb,
> err = ovs_nla_put_tunnel_info(user_skb,
> upcall_info->egress_tun_info);
> BUG_ON(err);
> - nla_nest_end(user_skb, nla);
> + if (nla)
> + nla_nest_end(user_skb, nla);
There is enough memory allocated for the netlink message accounting
for all attributes beforehand. So it is not required to check retuned
'nla' after each attributes addition to the msg.
> }
>
> if (upcall_info->actions_len) {
> @@ -497,7 +498,7 @@ static int queue_userspace_packet(struct datapath *dp,
> struct sk_buff *skb,
> err = ovs_nla_put_actions(upcall_info->actions,
> upcall_info->actions_len,
> user_skb);
> - if (!err)
> + if (!err && nla)
> nla_nest_end(user_skb, nla);
> else
> nla_nest_cancel(user_skb, nla);
> --
> 1.9.1
>
>
> _______________________________________________
> dev mailing list
> d...@openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
