From ddc0b3d1c63249250c3550351b624fc7995f844f Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Tue, 11 Jun 2024 18:58:16 +0200 Subject: [PATCH] wifi: cfg80211: wext: set ssids=NULL for passive scans BugLink: https://bugs.launchpad.net/bugs/2078304 commit 0941772342d59e48733131ac3a202fa1a4d832e9 upstream. In nl80211, we always set the ssids of a scan request to NULL when n_ssids==0 (passive scan). Drivers have relied on this behaviour in the past, so we fixed it in 6 GHz scan requests as well, and added a warning so we'd have assurance the API would always be called that way. syzbot found that wext doesn't ensure that, so we reach the check and trigger the warning. Fix the wext code to set the ssids pointer to NULL when there are none. Reported-by: syzbot+cd6135193ba6bb9ad158@syzkaller.appspotmail.com Fixes: f7a8b10bfd61 ("wifi: cfg80211: fix 6 GHz scan request building") Signed-off-by: Johannes Berg Signed-off-by: Greg Kroah-Hartman Signed-off-by: Portia Stephens Signed-off-by: Stefan Bader --- net/wireless/scan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 6aa046961df2..64295217b6ad 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -3580,8 +3580,10 @@ int cfg80211_wext_siwscan(struct net_device *dev, memcpy(creq->ssids[0].ssid, wreq->essid, wreq->essid_len); creq->ssids[0].ssid_len = wreq->essid_len; } - if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) + if (wreq->scan_type == IW_SCAN_TYPE_PASSIVE) { + creq->ssids = NULL; creq->n_ssids = 0; + } } for (i = 0; i < NUM_NL80211_BANDS; i++)