Subject: [PATCH AUTOSEL 5.14 21/40] mac80211: Drop frames from invalid MAC address in ad-hoc mode

From: Sasha Levin <[email-masked]>
Date: Tue, 5 Oct 2021 09:50:00 -0400

From: YueHaibing <[email-masked]>

[ Upstream commit a6555f844549cd190eb060daef595f94d3de1582 ]

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 <[email-masked]>
Link: https://lore.kernel.org/r/[email-masked]
Signed-off-by: Johannes Berg <[email-masked]>
Signed-off-by: Sasha Levin <[email-masked]>
---
 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 2563473b5cf1..e023e307c0c3 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;
-- 
2.33.0