[PATCH v2] Set ssid when authenticating

[Marc Bornand]

changes since v1:
- add some informations
- test it on wireless-2023-01-18 tag
- no real code change

When a connexion was established without going through
NL80211_CMD_CONNECT, the ssid was never set in the wireless_dev struct.
Now we set it during when an NL80211_CMD_AUTHENTICATE is issued.

It may be needed to test this on some additional hardware (tested with
iwlwifi and a AX201, and iwd on the userspace side), I could not test
things like roaming and p2p.

alternatives:
1. Do the same but during association and not authentication.
2. use ieee80211_bss_get_elem in nl80211_send_iface, this would report
   the right ssid to userspace, but this would not fix the root cause,
   this alos wa the behavior prior to 7b0a0e3c3a882 when the bug was
   introduced.

This applies to v6.2-rc8 or wireless-2023-01-18,

The last linux version known to be unafected is 5.19 and the bug was
backported to the 5.19.y releases

Reported-by: Yohan Prod'homme <kernel@xxxxxxxx>
Fixes: 7b0a0e3c3a88260b6fcb017e49f198463aa62ed1
Cc: stable@xxxxxxxxxxxxxxx
Link: https://bugzilla.kernel.org/show_bug.cgi?id=216711
Signed-off-by: Marc Bornand <dev.mbornand@xxxxxxxxxx>
---
 net/wireless/nl80211.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 33a82ecab9d5..f1627ea542b9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -10552,6 +10552,10 @@ static int nl80211_authenticate(struct sk_buff *skb, struct genl_info *info)
 		return -ENOENT;

 	wdev_lock(dev->ieee80211_ptr);
+
+	memcpy(dev->ieee80211_ptr->u.client.ssid, ssid, ssid_len);
+	dev->ieee80211_ptr->u.client.ssid_len = ssid_len;
+
 	err = cfg80211_mlme_auth(rdev, dev, &req);
 	wdev_unlock(dev->ieee80211_ptr);

@@ -11025,6 +11029,11 @@ static int nl80211_deauthenticate(struct sk_buff *skb, struct genl_info *info)
 	local_state_change = !!info->attrs[NL80211_ATTR_LOCAL_STATE_CHANGE];

 	wdev_lock(dev->ieee80211_ptr);
+
+	if (reason_code == WLAN_REASON_DEAUTH_LEAVING) {
+		dev->ieee80211_ptr->u.client.ssid_len = 0;
+	}
+
 	err = cfg80211_mlme_deauth(rdev, dev, bssid, ie, ie_len, reason_code,
 				   local_state_change);
 	wdev_unlock(dev->ieee80211_ptr);
--
2.39.1