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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org,
        Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>,
        Peter Ujfalusi <peter.ujfalusi@linux.intel.com>,
        Takashi Iwai <tiwai@suse.de>
Subject: [PATCH 5.15 047/110] ALSA: hda: Skip codec shutdown in case the codec is not registered
Date:   Mon,  7 Feb 2022 12:06:20 +0100
Message-Id: <20220207103803.876984550@linuxfoundation.org>
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From: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>

commit 1c7f0e349aa5f8f80b1cac3d4917405332e14cdf upstream.

If the codec->registered is not set then it means that pm_runtime is
not yet enabled and the codec->pcm_list_head has not been initialized.

The access to the not initialized pcm_list_head will lead a kernel crash
during shutdown.

Reported-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Tested-by: Guennadi Liakhovetski <guennadi.liakhovetski@linux.intel.com>
Fixes: b98444ed597d ("ALSA: hda: Suspend codec at shutdown")
Link: https://lore.kernel.org/r/20220201112144.29411-1-peter.ujfalusi@linux.intel.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 sound/pci/hda/hda_codec.c |    4 ++++
 1 file changed, 4 insertions(+)

--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -3000,6 +3000,10 @@ void snd_hda_codec_shutdown(struct hda_c
 {
 	struct hda_pcm *cpcm;
 
+	/* Skip the shutdown if codec is not registered */
+	if (!codec->registered)
+		return;
+
 	list_for_each_entry(cpcm, &codec->pcm_list_head, list)
 		snd_pcm_suspend_all(cpcm->pcm);