ASoC: SOF: Intel: cnl: 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.

The issue was reported with IPC4 firmware but the same condition is present
for IPC3.

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/20220712122357.31282-2-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

diff --git a/sound/soc/sof/intel/cnl.c b/sound/soc/sof/intel/cnl.c
index ccf46fc..a064453 100644 (file)
--- a/sound/soc/sof/intel/cnl.c
+++ b/sound/soc/sof/intel/cnl.c
@@ -60,17 +60,23 @@ irqreturn_t cnl_ipc4_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;
@@ -124,15 +130,20 @@ irqreturn_t cnl_ipc_irq_thread(int irq, void *context)
                                        CNL_DSP_REG_HIPCCTL,
                                        CNL_DSP_REG_HIPCCTL_DONE, 0);
 
-               spin_lock_irq(&sdev->ipc_lock);
+               if (likely(sdev->fw_state == SOF_FW_BOOT_COMPLETE)) {
+                       spin_lock_irq(&sdev->ipc_lock);
 
-               /* handle immediate reply from DSP core */
-               hda_dsp_ipc_get_reply(sdev);
-               snd_sof_ipc_reply(sdev, msg);
+                       /* handle immediate reply from DSP core */
+                       hda_dsp_ipc_get_reply(sdev);
+                       snd_sof_ipc_reply(sdev, msg);
 
-               cnl_ipc_dsp_done(sdev);
+                       cnl_ipc_dsp_done(sdev);
 
-               spin_unlock_irq(&sdev->ipc_lock);
+                       spin_unlock_irq(&sdev->ipc_lock);
+               } else {
+                       dev_dbg_ratelimited(sdev->dev, "IPC reply before FW_READY: %#x\n",
+                                           msg);
+               }
 
                ipc_irq = true;
        }