ASoC: SOF: Intel: mtl: Do not process IPC reply before firmware boot

It is not yet clear, but it is possible to create a firmware so broken
that it will send a reply message before a FW_READY message (it is not
yet clear if FW_READY will arrive later).
Since the reply_data is allocated only after the FW_READY message, this
will lead to a NULL pointer dereference if not filtered out.

Reported-by: Kai Vehmanen <kai.vehmanen@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Reviewed-by: Ranjani Sridharan <ranjani.sridharan@linux.intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20220712122357.31282-4-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/intel/mtl.c b/sound/soc/sof/intel/mtl.c
index 3a04358..a5e244e 100644 (file)
--- a/sound/soc/sof/intel/mtl.c
+++ b/sound/soc/sof/intel/mtl.c
@@ -512,17 +512,23 @@ static irqreturn_t mtl_ipc_irq_thread(int irq, void *context)
                 */
                if (primary & SOF_IPC4_MSG_DIR_MASK) {
                        /* Reply received */
-                       struct sof_ipc4_msg *data = sdev->ipc->msg.reply_data;
+                       if (likely(sdev->fw_state == SOF_FW_BOOT_COMPLETE)) {
+                               struct sof_ipc4_msg *data = sdev->ipc->msg.reply_data;
 
-                       data->primary = primary;
-                       data->extension = extension;
+                               data->primary = primary;
+                               data->extension = extension;
 
-                       spin_lock_irq(&sdev->ipc_lock);
+                               spin_lock_irq(&sdev->ipc_lock);
 
-                       snd_sof_ipc_get_reply(sdev);
-                       snd_sof_ipc_reply(sdev, data->primary);
+                               snd_sof_ipc_get_reply(sdev);
+                               snd_sof_ipc_reply(sdev, data->primary);
 
-                       spin_unlock_irq(&sdev->ipc_lock);
+                               spin_unlock_irq(&sdev->ipc_lock);
+                       } else {
+                               dev_dbg_ratelimited(sdev->dev,
+                                                   "IPC reply before FW_READY: %#x|%#x\n",
+                                                   primary, extension);
+                       }
                } else {
                        /* Notification received */
                        notification_data.primary = primary;