[PATCH 1/2] wifi: mac80211_hwsim: ignore non-generic netlink releases

[Zhao Li <enderaoelyther@gmail.com>]

Closing an unrelated netlink socket can remove mac80211_hwsim radios or
clear the active wmediumd registration when its port ID matches a generic
netlink socket.

mac80211_hwsim_netlink_notify() handles every NETLINK_URELEASE event,
but netlink port IDs are scoped by protocol. The notifier therefore treats
a release from another protocol as a MAC80211_HWSIM socket release.

Ignore release notifications unless they come from NETLINK_GENERIC.

LLM assistance was used to find the bug and review.

Fixes: 7882513bacb1 ("mac80211_hwsim driver support userspace frame tx/rx")
Fixes: e9ed49bf4c2c ("mac80211-hwsim: Add support for HWSIM_ATTR_DESTROY_RADIO_ON_CLOSE")
Cc: stable@vger.kernel.org
Signed-off-by: Zhao Li <enderaoelyther@gmail.com>
---
Validation: A W=1 module build with MODPOST passed. Not
reproduced; source review confirmed that netlink port IDs are scoped by
protocol.
Sparse C=2 passed. Targeted Smatch introduced no new diagnostics.

 drivers/net/wireless/virtual/mac80211_hwsim_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/wireless/virtual/mac80211_hwsim_main.c b/drivers/net/wireless/virtual/mac80211_hwsim_main.c
index b9446577ff49..fcbc7f4355bd 100644
--- a/drivers/net/wireless/virtual/mac80211_hwsim_main.c
+++ b/drivers/net/wireless/virtual/mac80211_hwsim_main.c
@@ -7197,7 +7197,7 @@ static int mac80211_hwsim_netlink_notify(struct notifier_block *nb,
 {
 	struct netlink_notify *notify = _notify;
 
-	if (state != NETLINK_URELEASE)
+	if (state != NETLINK_URELEASE || notify->protocol != NETLINK_GENERIC)
 		return NOTIFY_DONE;
 
 	remove_user_radios(notify->portid, hwsim_net_get_netgroup(notify->net));
-- 
2.56.0