[PATCH 5.10 142/221] net/sched: cls_flower: fix only mask bit check in the validate_ct_state

From: Greg Kroah-Hartman
Date: Mon Mar 29 2021 - 04:43:19 EST


From: wenxu <wenxu@xxxxxxxxx>

[ Upstream commit afa536d8405a9ca36e45ba035554afbb8da27b82 ]

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: 1bcc51ac0731 ("net/sched: cls_flower: Reject invalid ct_state flags rules")
Fixes: 3aed8b63336c ("net/sched: cls_flower: validate ct_state for invalid and reply flags")
Signed-off-by: wenxu <wenxu@xxxxxxxxx>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/sched/cls_flower.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 46c1b3e9f66a..14316ba9b3b3 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -1432,7 +1432,7 @@ 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)
--
2.30.1