[lvc-project] [PATCH] ALSA: hda: cs35l41: Fix NULL pointer dereference in cs35l41_hda_read_acpi()

[Denis Arefev]

The acpi_get_first_physical_node() function can return NULL, in which
case the get_device() function also returns NULL, but this value is
then dereferenced without checking,so add a check to prevent a crash.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 7b2f3eb492da ("ALSA: hda: cs35l41: Add support for CS35L41 in HDA systems")
Cc: stable at vger.kernel.org
Signed-off-by: Denis Arefev <arefev at swemel.ru>
---
 sound/hda/codecs/side-codecs/cs35l41_hda.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/sound/hda/codecs/side-codecs/cs35l41_hda.c b/sound/hda/codecs/side-codecs/cs35l41_hda.c
index c0f2a3ff77a1..21e00055c0c4 100644
--- a/sound/hda/codecs/side-codecs/cs35l41_hda.c
+++ b/sound/hda/codecs/side-codecs/cs35l41_hda.c
@@ -1901,6 +1901,8 @@ static int cs35l41_hda_read_acpi(struct cs35l41_hda *cs35l41, const char *hid, i
 
 	cs35l41->dacpi = adev;
 	physdev = get_device(acpi_get_first_physical_node(adev));
+	if (!physdev)
+		return -ENODEV;
 
 	sub = acpi_get_subsystem_id(ACPI_HANDLE(physdev));
 	if (IS_ERR(sub))
-- 
2.43.0