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authorJohannes Berg <johannes.berg@intel.com>2011-09-22 14:59:04 -0700
committerJohn W. Linville <linville@tuxdriver.com>2011-09-26 14:55:50 -0400
commit6c80c39d9a6986a566c30d797aae37bfb697eea3 (patch)
tree8ce4d0e71e4daacf3724ab15a8265f1a53926325 /drivers/net
parent1b9ca0272ffae212e726380f66777b30a56ed7a5 (diff)
iwlagn: fix dangling scan request
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@kernel.org [3.0] Reported-by: Peng Yan <peng.yan@intel.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com> Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/wireless/iwlwifi/iwl-scan.c30
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 dd6937e9705..77e528f5db8 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;