6.9-stable review patch. If anyone has any objections, please let me know.
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From: Johannes Berg johannes.berg@intel.com
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 johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/wireless/scan.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -3492,8 +3492,10 @@ int cfg80211_wext_siwscan(struct net_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++)