From: Johannes Berg <johannes.berg@xxxxxxxxx>
If iwl_scan_initiate() fails for any reason,
priv->scan_request and priv->scan_vif are left
dangling. This can lead to a crash later when
iwl_bg_scan_completed() tries to run a pending
scan request.
In practice, this seems to be very rare due to
the STATUS_SCANNING check earlier. That check,
however, is wrong -- it should allow a scan to
be queued when a reset/roc scan is going on.
When a normal scan is already going on, a new
one can't be issued by mac80211, so that code
can be removed completely. I introduced this
bug when adding off-channel support in commit
266af4c745952e9bebf687dd68af58df553cb59d.
Cc: stable@xxxxxxxxxx [3.0]
Reported-by: Peng Yan <peng.yan@xxxxxxxxx>
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@xxxxxxxxx>
---
hese patches are also available from wireless branch on
git://git.kernel.org/pub/scm/linux/kernel/git/iwlwifi/iwlwifi.git
drivers/net/wireless/iwlwifi/iwl-scan.c | 30 ++++++++++++++++--------------
1 files changed, 16 insertions(+), 14 deletions(-)
diff --git a/drivers/net/wireless/iwlwifi/iwl-scan.c b/drivers/net/wireless/iwlwifi/iwl-scan.c
index dd6937e..77e528f 100644
--- a/drivers/net/wireless/iwlwifi/iwl-scan.c
+++ b/drivers/net/wireless/iwlwifi/iwl-scan.c
@@ -405,31 +405,33 @@ int iwl_mac_hw_scan(struct ieee80211_hw *hw,
mutex_lock(&priv->mutex);
- if (test_bit(STATUS_SCANNING, &priv->status) &&
- priv->scan_type != IWL_SCAN_NORMAL) {
- IWL_DEBUG_SCAN(priv, "Scan already in progress.\n");
- ret = -EAGAIN;
- goto out_unlock;
- }
-
- /* mac80211 will only ask for one band at a time */
- priv->scan_request = req;
- priv->scan_vif = vif;
-
/*
* If an internal scan is in progress, just set
* up the scan_request as per above.
*/
if (priv->scan_type != IWL_SCAN_NORMAL) {
- IWL_DEBUG_SCAN(priv, "SCAN request during internal scan\n");
+ IWL_DEBUG_SCAN(priv,
+ "SCAN request during internal scan - defer\n");
+ priv->scan_request = req;
+ priv->scan_vif = vif;
ret = 0;
- } else
+ } else {
+ priv->scan_request = req;
+ priv->scan_vif = vif;
+ /*
+ * mac80211 will only ask for one band at a time
+ * so using channels[0] here is ok
+ */
ret = iwl_scan_initiate(priv, vif, IWL_SCAN_NORMAL,
req->channels[0]->band);
+ if (ret) {
+ priv->scan_request = NULL;
+ priv->scan_vif = NULL;
+ }
+ }
IWL_DEBUG_MAC80211(priv, "leave\n");
-out_unlock:
mutex_unlock(&priv->mutex);
return ret;
--
1.7.0.4
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