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cfg80211: fix connect/disconnect edge cases 

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.

Cc: stable@vger.kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
hifive-unleashed-5.1
Johannes Berg 2017-10-17 21:56:20 +02:00
parent 2bdd713b92
commit 51e13359cd
1 changed files with 41 additions and 9 deletions
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50
net/wireless/sme.c
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@ -522,11 +522,6 @@ static int cfg80211_sme_connect(struct wireless_dev *wdev,
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;
@ -1063,11 +1058,35 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
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);
@ -1118,7 +1137,12 @@ int cfg80211_connect(struct cfg80211_registered_device *rdev,
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;
}
@ -1145,6 +1169,14 @@ int cfg80211_disconnect(struct cfg80211_registered_device *rdev,
else if (wdev->ssid_len)
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;
}