This is a note to let you know that I've just added the patch titled cfg80211: fix connect/disconnect edge cases to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: cfg80211-fix-connect-disconnect-edge-cases.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 51e13359cd5ea34acc62c90627603352956380af Mon Sep 17 00:00:00 2001 From: Johannes Berg <johannes.berg@xxxxxxxxx> Date: Tue, 17 Oct 2017 21:56:20 +0200 Subject: cfg80211: fix connect/disconnect edge cases From: Johannes Berg <johannes.berg@xxxxxxxxx> commit 51e13359cd5ea34acc62c90627603352956380af upstream. If we try to connect while already connected/connecting, but this fails, we set ssid_len=0 but leave current_bss hanging, leading to errors. Check all of this better, first of all ensuring that we can't try to connect to a different SSID while connected/ing; ensure that prev_bssid is set for re-association attempts even in the case of the driver supporting the connect() method, and don't reset ssid_len in the failure cases. While at it, also reset ssid_len while disconnecting unless we were connected and expect a disconnected event, and warn on a successful connection without ssid_len being set. Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/wireless/sme.c | 50 +++++++++++++++++++++++++++++++++++++++++--------- 1 file changed, 41 insertions(+), 9 deletions(-) --- a/net/wireless/sme.c +++ b/net/wireless/sme.c @@ -505,11 +505,6 @@ static int cfg80211_sme_connect(struct w return -EOPNOTSUPP; if (wdev->current_bss) { - if (!prev_bssid) - return -EALREADY; - if (prev_bssid && - !ether_addr_equal(prev_bssid, wdev->current_bss->pub.bssid)) - return -ENOTCONN; cfg80211_unhold_bss(wdev->current_bss); cfg80211_put_bss(wdev->wiphy, &wdev->current_bss->pub); wdev->current_bss = NULL; @@ -1025,11 +1020,35 @@ int cfg80211_connect(struct cfg80211_reg ASSERT_WDEV_LOCK(wdev); - if (WARN_ON(wdev->connect_keys)) { - kzfree(wdev->connect_keys); - wdev->connect_keys = NULL; + /* + * If we have an ssid_len, we're trying to connect or are + * already connected, so reject a new SSID unless it's the + * same (which is the case for re-association.) + */ + if (wdev->ssid_len && + (wdev->ssid_len != connect->ssid_len || + memcmp(wdev->ssid, connect->ssid, wdev->ssid_len))) + return -EALREADY; + + /* + * If connected, reject (re-)association unless prev_bssid + * matches the current BSSID. + */ + if (wdev->current_bss) { + if (!prev_bssid) + return -EALREADY; + if (!ether_addr_equal(prev_bssid, wdev->current_bss->pub.bssid)) + return -ENOTCONN; } + /* + * Reject if we're in the process of connecting with WEP, + * this case isn't very interesting and trying to handle + * it would make the code much more complex. + */ + if (wdev->connect_keys) + return -EINPROGRESS; + cfg80211_oper_and_ht_capa(&connect->ht_capa_mask, rdev->wiphy.ht_capa_mod_mask); @@ -1080,7 +1099,12 @@ int cfg80211_connect(struct cfg80211_reg if (err) { wdev->connect_keys = NULL; - wdev->ssid_len = 0; + /* + * This could be reassoc getting refused, don't clear + * ssid_len in that case. + */ + if (!wdev->current_bss) + wdev->ssid_len = 0; return err; } @@ -1105,5 +1129,13 @@ int cfg80211_disconnect(struct cfg80211_ else if (wdev->current_bss) err = rdev_disconnect(rdev, dev, reason); + /* + * Clear ssid_len unless we actually were fully connected, + * in which case cfg80211_disconnected() will take care of + * this later. + */ + if (!wdev->current_bss) + wdev->ssid_len = 0; + return err; } Patches currently in stable-queue which might be from johannes.berg@xxxxxxxxx are queue-4.9/cfg80211-fix-connect-disconnect-edge-cases.patch