Merge tag 'wireless-2025-07-10' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless

Johannes Berg says:

====================
Quite a number of fixes still:

 - mt76 (hadn't sent any fixes so far)
   - RCU
   - scanning
   - decapsulation offload
   - interface combinations
 - rt2x00: build fix (bad function pointer prototype)
 - cfg80211: prevent A-MSDU flipping attacks in mesh
 - zd1211rw: prevent race ending with NULL ptr deref
 - cfg80211/mac80211: more S1G fixes
 - mwifiex: avoid WARN on certain RX frames
 - mac80211:
   - avoid stack data leak in WARN cases
   - fix non-transmitted BSSID search
     (on certain multi-BSSID APs)
   - always initialize key list so driver
     iteration won't crash
   - fix monitor interface in device restart
   - fix __free() annotation usage

* tag 'wireless-2025-07-10' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless: (26 commits)
  wifi: mac80211: add the virtual monitor after reconfig complete
  wifi: mac80211: always initialize sdata::key_list
  wifi: mac80211: Fix uninitialized variable with __free() in ieee80211_ml_epcs()
  wifi: mt76: mt792x: Limit the concurrent STA and SoftAP to operate on the same channel
  wifi: mt76: mt7925: Fix null-ptr-deref in mt7925_thermal_init()
  wifi: mt76: fix queue assignment for deauth packets
  wifi: mt76: add a wrapper for wcid access with validation
  wifi: mt76: mt7921: prevent decap offload config before STA initialization
  wifi: mt76: mt7925: prevent NULL pointer dereference in mt7925_sta_set_decap_offload()
  wifi: mt76: mt7925: fix incorrect scan probe IE handling for hw_scan
  wifi: mt76: mt7925: fix invalid array index in ssid assignment during hw scan
  wifi: mt76: mt7925: fix the wrong config for tx interrupt
  wifi: mt76: Remove RCU section in mt7996_mac_sta_rc_work()
  wifi: mt76: Move RCU section in mt7996_mcu_add_rate_ctrl()
  wifi: mt76: Move RCU section in mt7996_mcu_add_rate_ctrl_fixed()
  wifi: mt76: Move RCU section in mt7996_mcu_set_fixed_field()
  wifi: mt76: Assume __mt76_connac_mcu_alloc_sta_req runs in atomic context
  wifi: prevent A-MSDU attacks in mesh networks
  wifi: rt2x00: fix remove callback type mismatch
  wifi: mac80211: reject VHT opmode for unsupported channel widths
  ...
====================

Link: https://patch.msgid.link/20250710122212.24272-3-johannes@sipsolutions.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

1 files changed, 33 insertions, 12 deletions

diff --git a/include/linux/ieee80211.h b/include/linux/ieee80211.h
index 22f39e5e2ff1..996be3c2cff0 100644
--- a/include/linux/ieee80211.h
+++ b/include/linux/ieee80211.h
@@ -663,18 +663,6 @@ static inline bool ieee80211_s1g_has_cssid(__le16 fc)
 }
 
 /**
- * ieee80211_is_s1g_short_beacon - check if frame is an S1G short beacon
- * @fc: frame control bytes in little-endian byteorder
- * Return: whether or not the frame is an S1G short beacon,
- *	i.e. it is an S1G beacon with 'next TBTT' flag set
- */
-static inline bool ieee80211_is_s1g_short_beacon(__le16 fc)
-{
-	return ieee80211_is_s1g_beacon(fc) &&
-		(fc & cpu_to_le16(IEEE80211_S1G_BCN_NEXT_TBTT));
-}
-
-/**
  * ieee80211_is_atim - check if IEEE80211_FTYPE_MGMT && IEEE80211_STYPE_ATIM
  * @fc: frame control bytes in little-endian byteorder
  * Return: whether or not the frame is an ATIM frame
@@ -4901,6 +4889,39 @@ static inline bool ieee80211_is_ftm(struct sk_buff *skb)
 	return false;
 }
 
+/**
+ * ieee80211_is_s1g_short_beacon - check if frame is an S1G short beacon
+ * @fc: frame control bytes in little-endian byteorder
+ * @variable: pointer to the beacon frame elements
+ * @variable_len: length of the frame elements
+ * Return: whether or not the frame is an S1G short beacon. As per
+ *	IEEE80211-2024 11.1.3.10.1, The S1G beacon compatibility element shall
+ *	always be present as the first element in beacon frames generated at a
+ *	TBTT (Target Beacon Transmission Time), so any frame not containing
+ *	this element must have been generated at a TSBTT (Target Short Beacon
+ *	Transmission Time) that is not a TBTT. Additionally, short beacons are
+ *	prohibited from containing the S1G beacon compatibility element as per
+ *	IEEE80211-2024 9.3.4.3 Table 9-76, so if we have an S1G beacon with
+ *	either no elements or the first element is not the beacon compatibility
+ *	element, we have a short beacon.
+ */
+static inline bool ieee80211_is_s1g_short_beacon(__le16 fc, const u8 *variable,
+						 size_t variable_len)
+{
+	if (!ieee80211_is_s1g_beacon(fc))
+		return false;
+
+	/*
+	 * If the frame does not contain at least 1 element (this is perfectly
+	 * valid in a short beacon) and is an S1G beacon, we have a short
+	 * beacon.
+	 */
+	if (variable_len < 2)
+		return true;
+
+	return variable[0] != WLAN_EID_S1G_BCN_COMPAT;
+}
+
 struct element {
 	u8 id;
 	u8 datalen;