iwlwifi: mvm: don't allow sched scans without matches to be started

[ Upstream commit 5e56276e7555b34550d51459a801ff75eca8b907 ]

The firmware can perform a scheduled scan with not matchsets passed,
but it can't send notification that results were found.  Since the
userspace then cannot know when we got new results and the firmware
wouldn't trigger a wake in case we are sleeping, it's better not to
allow scans without matchsets.

This fixes https://bugzilla.kernel.org/show_bug.cgi?id=110831

Cc: <stable@vger.kernel.org> [3.17+]
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
[SL: Backport to 4.1]
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

diff --git a/drivers/net/wireless/iwlwifi/mvm/mac80211.c b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
index 9779c1e5688c3fa19e0841d4eb9ca1952e6d0431..90e8b662e44d3bbd3e3479c8ee884f33cba3fd7e 100644 (file)
--- a/drivers/net/wireless/iwlwifi/mvm/mac80211.c
+++ b/drivers/net/wireless/iwlwifi/mvm/mac80211.c
@@ -2797,6 +2797,10 @@ static int iwl_mvm_mac_sched_scan_start(struct ieee80211_hw *hw,
        struct iwl_mvm *mvm = IWL_MAC80211_GET_MVM(hw);
        int ret;
 
+       /* we don't support "match all" in the firmware */
+       if (!req->n_match_sets)
+               return -EOPNOTSUPP;
+
        if (!(mvm->fw->ucode_capa.capa[0] & IWL_UCODE_TLV_CAPA_UMAC_SCAN)) {
                ret = iwl_mvm_cancel_scan_wait_notif(mvm, IWL_MVM_SCAN_OS);
                if (ret)