openvswitch: meter: fix NULL pointer dereference in ovs_meter_cmd_reply_start

It seems that the intention of the code is to null check the value
returned by function genlmsg_put. But the current code is null
checking the address of the pointer that holds the value returned
by genlmsg_put.

Fix this by properly null checking the value returned by function
genlmsg_put in order to avoid a pontential null pointer dereference.

Addresses-Coverity-ID: 1461561 ("Dereference before null check")
Addresses-Coverity-ID: 1461562 ("Dereference null return value")
Fixes: 96fbc13d7e77 ("openvswitch: Add meter infrastructure")
Signed-off-by: Gustavo A. R. Silva <garsilva@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/openvswitch/meter.c b/net/openvswitch/meter.c
index 52ddd6c408b3528e63b3864d89930a11bd22ab2f..3fbfc78991ac5748e098dc372727600d0af21ba6 100644 (file)
--- a/net/openvswitch/meter.c
+++ b/net/openvswitch/meter.c
@@ -99,7 +99,7 @@ ovs_meter_cmd_reply_start(struct genl_info *info, u8 cmd,
        *ovs_reply_header = genlmsg_put(skb, info->snd_portid,
                                        info->snd_seq,
                                        &dp_meter_genl_family, 0, cmd);
-       if (!ovs_reply_header) {
+       if (!*ovs_reply_header) {
                nlmsg_free(skb);
                return ERR_PTR(-EMSGSIZE);
        }