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From:   YueHaibing <yuehaibing@huawei.com>
To:     <johannes@sipsolutions.net>, <davem@davemloft.net>,
        <kuba@kernel.org>
CC:     <linux-wireless@vger.kernel.org>, <netdev@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, YueHaibing <yuehaibing@huawei.com>
Subject: [PATCH] mac80211: Drop frames from invalid MAC address in ad-hoc mode
Date:   Fri, 27 Aug 2021 22:42:30 +0800
Message-ID: <20210827144230.39944-1-yuehaibing@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

WARNING: CPU: 1 PID: 9 at net/mac80211/sta_info.c:554
sta_info_insert_rcu+0x121/0x12a0
Modules linked in:
CPU: 1 PID: 9 Comm: kworker/u8:1 Not tainted 5.14.0-rc7+ #253
Workqueue: phy3 ieee80211_iface_work
RIP: 0010:sta_info_insert_rcu+0x121/0x12a0
...
Call Trace:
 ieee80211_ibss_finish_sta+0xbc/0x170
 ieee80211_ibss_work+0x13f/0x7d0
 ieee80211_iface_work+0x37a/0x500
 process_one_work+0x357/0x850
 worker_thread+0x41/0x4d0

If an Ad-Hoc node receives packets with invalid source MAC address,
it hits a WARN_ON in sta_info_insert_check(), this can spam the log.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 net/mac80211/rx.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/mac80211/rx.c b/net/mac80211/rx.c
index 2563473..e023e30 100644
--- a/net/mac80211/rx.c
+++ b/net/mac80211/rx.c
@@ -4053,7 +4053,8 @@ static bool ieee80211_accept_frame(struct ieee80211_rx_data *rx)
 		if (!bssid)
 			return false;
 		if (ether_addr_equal(sdata->vif.addr, hdr->addr2) ||
-		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2))
+		    ether_addr_equal(sdata->u.ibss.bssid, hdr->addr2) ||
+		    !is_valid_ether_addr(hdr->addr2))
 			return false;
 		if (ieee80211_is_beacon(hdr->frame_control))
 			return true;
-- 
1.8.3.1