[PATCH 5.18 106/158] amt: drop unexpected query message

Greg Kroah-Hartman
2022-07-27T17:40:22Z

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 239d886601e38d948a28f3b2a1c9ce5f01bf75f2 ]

AMT gateway interface should not receive unexpected query messages.
In order to drop unexpected query messages, it checks nonce.
And it also checks ready4 and ready6 variables to drop duplicated messages.

Fixes: cbc21dc1cfe9 ("amt: add data plane of amt interface")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/amt.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index 0811a5211ec4..5c65908abd5a 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -967,8 +967,11 @@ static void amt_event_send_request(struct amt_dev *amt)
goto out;
}

- if (!amt->req_cnt)
+ if (!amt->req_cnt) {
+ WRITE_ONCE(amt->ready4, false);
+ WRITE_ONCE(amt->ready6, false);
get_random_bytes(&amt->nonce, sizeof(__be32));
+ }

amt_send_request(amt, false);
amt_send_request(amt, true);
@@ -2353,6 +2356,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
if (amtmq->reserved || amtmq->version)
return true;

+ if (amtmq->nonce != amt->nonce)
+ return true;
+
hdr_size -= sizeof(*eth);
if (iptunnel_pull_header(skb, hdr_size, htons(ETH_P_TEB), false))
return true;
@@ -2367,6 +2373,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,

iph = ip_hdr(skb);
if (iph->version == 4) {
+ if (READ_ONCE(amt->ready4))
+ return true;
+
if (!pskb_may_pull(skb, sizeof(*iph) + AMT_IPHDR_OPTS +
sizeof(*ihv3)))
return true;
@@ -2389,6 +2398,9 @@ static bool amt_membership_query_handler(struct amt_dev *amt,
struct mld2_query *mld2q;
struct ipv6hdr *ip6h;

+ if (READ_ONCE(amt->ready6))
+ return true;
+
if (!pskb_may_pull(skb, sizeof(*ip6h) + AMT_IP6HDR_OPTS +
sizeof(*mld2q)))
return true;
--
2.35.1