datapath: avoid memory corruption in queue_userspace_packet()

In queue_userspace_packet(), the ovs_nla_put_flow return value is
not checked. This is fine as long as key_attr_size() returns the
correct value. In case it does not, the current code may corrupt buffer
memory. Add a run time assertion catch this case to avoid silent
failure.

Reported-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Pravin B Shelar <pshelar@nicira.com>

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 1d2f414..a4d6473 100644 (file)
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -487,7 +487,8 @@ static int queue_userspace_packet(struct datapath *dp, struct sk_buff *skb,
        upcall->dp_ifindex = dp_ifindex;
 
        nla = nla_nest_start(user_skb, OVS_PACKET_ATTR_KEY);
-       ovs_nla_put_flow(upcall_info->key, upcall_info->key, user_skb);
+       err = ovs_nla_put_flow(upcall_info->key, upcall_info->key, user_skb);
+       BUG_ON(err);
        nla_nest_end(user_skb, nla);
 
        if (upcall_info->userdata)