iwlwifi: mvm: avoid use-after-free on iwl_mvm_d0i3_enable_tx() [BUGFIX]

qos_seq points (to a struct) inside the command response data.

Make sure to free the response only after qos_seq is not
needed anymore.

type=bugfix
bug=not-tracked
fixes=I78c07110b59dcd389207bd2b168b0a2760839fe0

Change-Id: I619ce2c17e064dc98c7be9abc1e23175fdc8fb9a
Reported-by: Heng Luo <heng.luo@intel.com>
Signed-off-by: Eliad Peller <eliadx.peller@intel.com>
Reviewed-on: https://gerrit.rds.intel.com/r/55381Reviewed-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>
Tested-by: IWL Jenkins
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/mvm/ops.c

@@ -1263,11 +1263,13 @@ static void iwl_mvm_d0i3_exit_work(struct work_struct *wk)
 		ieee80211_iterate_active_interfaces(
 			mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
 			iwl_mvm_d0i3_disconnect_iter, mvm);
-
-	iwl_free_resp(&get_status_cmd);
 out:
 	iwl_mvm_d0i3_enable_tx(mvm, qos_seq);
 
+	/* qos_seq might point inside resp_pkt, so free it only now */
+	if (get_status_cmd.resp_pkt)
+		iwl_free_resp(&get_status_cmd);
+
 	/* the FW might have updated the regdomain */
 	iwl_mvm_update_changed_regdom(mvm);