[PATCH 5.15 046/120] wifi: cfg80211: dont allow multi-BSSID in S1G

Greg Kroah-Hartman
2022-12-05T19:39:07Z

From: Johannes Berg <johannes.berg@intel.com>

[ Upstream commit acd3c92acc7aaec50a94d0a7faf7ccd74e952493 ]

In S1G beacon frames there shouldn't be multi-BSSID elements
since that's not supported, remove that to avoid a potential
integer underflow and/or misparsing the frames due to the
different length of the fixed part of the frame.

While at it, initialize non_tx_data so we don't send garbage
values to the user (even if it doesn't seem to matter now.)

Reported-and-tested-by: Sönke Huster <shuster@seemoo.tu-darmstadt.de>
Fixes: 9eaffe5078ca ("cfg80211: convert S1G beacon to scan results")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
net/wireless/scan.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 937ec4c2a3bf..ef31e401d791 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -2477,10 +2477,15 @@ cfg80211_inform_bss_frame_data(struct wiphy *wiphy,
const struct cfg80211_bss_ies *ies1, *ies2;
size_t ielen = len - offsetof(struct ieee80211_mgmt,
u.probe_resp.variable);
- struct cfg80211_non_tx_bss non_tx_data;
+ struct cfg80211_non_tx_bss non_tx_data = {};

res = cfg80211_inform_single_bss_frame_data(wiphy, data, mgmt,
len, gfp);
+
+ /* don't do any further MBSSID handling for S1G */
+ if (ieee80211_is_s1g_beacon(mgmt->frame_control))
+ return res;
+
if (!res || !wiphy->support_mbssid ||
!cfg80211_find_ie(WLAN_EID_MULTIPLE_BSSID, ie, ielen))
return res;
--
2.35.1