net/sched: cls_flower: fix only mask bit check in the validate_ct_state

The ct_state validate should not only check the mask bit and also
check mask_bit & key_bit..
For the +new+est case example, The 'new' and 'est' bits should be
set in both state_mask and state flags. Or the -new-est case also
will be reject by kernel.
When Openvswitch with two flows
ct_state=+trk+new,action=commit,forward
ct_state=+trk+est,action=forward

A packet go through the kernel  and the contrack state is invalid,
The ct_state will be +trk-inv. Upcall to the ovs-vswitchd, the
finally dp action will be drop with -new-est+trk.

Fixes: 1bcc51ac07 ("net/sched: cls_flower: Reject invalid ct_state flags rules")
Fixes: 3aed8b6333 ("net/sched: cls_flower: validate ct_state for invalid and reply flags")
Signed-off-by: wenxu <wenxu@ucloud.cn>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/sched/cls_flower.c

@@ -1451,7 +1451,7 @@ static int fl_set_key_ct(struct nlattr **tb,
 			       &mask->ct_state, TCA_FLOWER_KEY_CT_STATE_MASK,
 			       sizeof(key->ct_state));
 
-		err = fl_validate_ct_state(mask->ct_state,
+		err = fl_validate_ct_state(key->ct_state & mask->ct_state,
 					   tb[TCA_FLOWER_KEY_CT_STATE_MASK],
 					   extack);
 		if (err)