RDMA/nldev: Enforce device index check for port callback

IB device index is nldev's handler and it should be checked always.

Fixes: c3f66f7b ("RDMA/netlink: Implement nldev port doit callback")
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Acked-by: Doug Ledford <dledford@redhat.com>
[ Applying directly, since Doug fried his SSD's and is rebuilding  - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/infiniband/core/nldev.c

@@ -214,7 +214,9 @@ static int nldev_port_get_doit(struct sk_buff *skb, struct nlmsghdr *nlh,
 
 	err = nlmsg_parse(nlh, 0, tb, RDMA_NLDEV_ATTR_MAX - 1,
 			  nldev_policy, extack);
-	if (err || !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
+	if (err ||
+	    !tb[RDMA_NLDEV_ATTR_DEV_INDEX] ||
+	    !tb[RDMA_NLDEV_ATTR_PORT_INDEX])
 		return -EINVAL;
 
 	index = nla_get_u32(tb[RDMA_NLDEV_ATTR_DEV_INDEX]);