[PATCH 5.4 40/67] ALSA: hda: fix NULL pointer dereference during suspend

From: Greg Kroah-Hartman
Date: Mon Aug 10 2020 - 11:36:13 EST


From: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>

[ Upstream commit 7fcd9bb5acd01250bcae1ecc0cb8b8d4bb5b7e63 ]

When the ASoC card registration fails and the codec component driver
never probes, the codec device is not initialized and therefore
memory for codec->wcaps is not allocated. This results in a NULL pointer
dereference when the codec driver suspend callback is invoked during
system suspend. Fix this by returning without performing any actions
during codec suspend/resume if the card was not registered successfully.

Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@xxxxxxxxxxxxxxx>
Signed-off-by: Ranjani Sridharan <ranjani.sridharan@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200728231011.1454066-1-ranjani.sridharan@xxxxxxxxxxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
sound/pci/hda/hda_codec.c | 8 ++++++++
1 file changed, 8 insertions(+)

diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 07c03c32715a9..801abf0fc98b3 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -2924,6 +2924,10 @@ static int hda_codec_runtime_suspend(struct device *dev)
struct hda_codec *codec = dev_to_hda_codec(dev);
unsigned int state;

+ /* Nothing to do if card registration fails and the component driver never probes */
+ if (!codec->card)
+ return 0;
+
cancel_delayed_work_sync(&codec->jackpoll_work);
state = hda_call_codec_suspend(codec);
if (codec->link_down_at_suspend ||
@@ -2938,6 +2942,10 @@ static int hda_codec_runtime_resume(struct device *dev)
{
struct hda_codec *codec = dev_to_hda_codec(dev);

+ /* Nothing to do if card registration fails and the component driver never probes */
+ if (!codec->card)
+ return 0;
+
codec_display_power(codec, true);
snd_hdac_codec_link_up(&codec->core);
hda_call_codec_resume(codec);
--
2.25.1