wifi: mac80211: fix vendor-specific inheritance

JIRA: https://issues.redhat.com/browse/RHEL-79791

commit 130067e
Author: Johannes Berg <johannes.berg@intel.com>
Date:   Fri Feb 21 11:24:51 2025 +0100

    wifi: mac80211: fix vendor-specific inheritance
    
    If there's any vendor-specific element in the subelements
    then the outer element parsing must not parse any vendor
    element at all. This isn't implemented correctly now due
    to parsing into the pointers and then overriding them, so
    explicitly skip vendor elements if any exist in the sub-
    elements (non-transmitted profile or per-STA profile).
    
    Fixes: 671042a ("mac80211: support non-inheritance element")
    Reviewed-by: Ilan Peer <ilan.peer@intel.com>
    Reviewed-by: Miriam Rachel Korenblit <miriam.rachel.korenblit@intel.com>
    Link: https://patch.msgid.link/20250221112451.fd71e5268840.I9db3e6a3367e6ff38d052d07dc07005f0dd3bd5c@changeid
    Signed-off-by: Johannes Berg <johannes.berg@intel.com>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

net/mac80211/parse.c

@@ -48,6 +48,7 @@ struct ieee80211_elems_parse {
 	const struct element *ml_epcs_elem;
 
 	bool multi_link_inner;
+	bool skip_vendor;
 
 	/*
 	 * scratch buffer that can be used for various element parsing related
@@ -400,6 +401,9 @@ _ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params,
 					IEEE80211_PARSE_ERR_BAD_ELEM_SIZE;
 			break;
 		case WLAN_EID_VENDOR_SPECIFIC:
+			if (elems_parse->skip_vendor)
+				break;
+
 			if (elen >= 4 && pos[0] == 0x00 && pos[1] == 0x50 &&
 			    pos[2] == 0xf2) {
 				/* Microsoft OUI (00:50:F2) */
@@ -1054,12 +1058,16 @@ ieee802_11_parse_elems_full(struct ieee80211_elems_parse_params *params)
 		multi_link_inner = true;
 	}
 
+	elems_parse->skip_vendor =
+		cfg80211_find_elem(WLAN_EID_VENDOR_SPECIFIC,
+				   sub.start, sub.len);
 	elems->crc = _ieee802_11_parse_elems_full(params, elems_parse,
 						  non_inherit);
 
 	/* Override with nontransmitted/per-STA profile if found */
 	if (sub.len) {
 		elems_parse->multi_link_inner = multi_link_inner;
+		elems_parse->skip_vendor = false;
 		_ieee802_11_parse_elems_full(&sub, elems_parse, NULL);
 	}