[PATCH 5.18 105/158] amt: drop unexpected advertisement message

Greg Kroah-Hartman
2022-07-27T17:45:00Z

From: Taehee Yoo <ap420073@gmail.com>

[ Upstream commit 40185f359fbabaa61da754cc29d12f3a41e0a987 ]

AMT gateway interface should not receive unexpected advertisement messages.
In order to drop these packets, it should check nonce and amt->status.

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 | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/net/amt.c b/drivers/net/amt.c
index 2fe56640e493..0811a5211ec4 100644
--- a/drivers/net/amt.c
+++ b/drivers/net/amt.c
@@ -2260,6 +2260,10 @@ static bool amt_advertisement_handler(struct amt_dev *amt, struct sk_buff *skb)
ipv4_is_zeronet(amta->ip4))
return true;

+ if (amt->status != AMT_STATUS_SENT_DISCOVERY ||
+ amt->nonce != amta->nonce)
+ return true;
+
amt->remote_ip = amta->ip4;
netdev_dbg(amt->dev, "advertised remote ip = %pI4\n", &amt->remote_ip);
mod_delayed_work(amt_wq, &amt->req_wq, 0);
@@ -2975,6 +2979,7 @@ static int amt_dev_open(struct net_device *dev)

amt->req_cnt = 0;
amt->remote_ip = 0;
+ amt->nonce = 0;
get_random_bytes(&amt->key, sizeof(siphash_key_t));

amt->status = AMT_STATUS_INIT;
--
2.35.1