From a14a6219996ee6f6e858d83b11affc7907633687 Mon Sep 17 00:00:00 2001
From: Mark Pearson <markpearson@lenovo.com>
Date: Tue, 2 Mar 2021 09:10:03 -0500
Subject: [PATCH] ALSA: hda: ignore invalid NHLT table
Git-commit: a14a6219996ee6f6e858d83b11affc7907633687
Patch-mainline: v5.12-rc3
References: git-fixes
On some Lenovo systems if the microphone is disabled in the BIOS
only the NHLT table header is created, with no data. This means
the endpoints field is not correctly set to zero - leading to an
unintialised variable and hence invalid descriptors are parsed
leading to page faults.
The Lenovo firmware team is addressing this, but adding a check
preventing invalid tables being parsed is worthwhile.
Tested on a Lenovo T14.
Tested-by: Philipp Leskovitz <philipp.leskovitz@secunet.com>
Reported-by: Philipp Leskovitz <philipp.leskovitz@secunet.com>
Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Link: https://lore.kernel.org/r/20210302141003.7342-1-markpearson@lenovo.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
sound/hda/intel-nhlt.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/sound/hda/intel-nhlt.c b/sound/hda/intel-nhlt.c
index d053beccfaec..e2237239d922 100644
--- a/sound/hda/intel-nhlt.c
+++ b/sound/hda/intel-nhlt.c
@@ -39,6 +39,11 @@ int intel_nhlt_get_dmic_geo(struct device *dev, struct nhlt_acpi_table *nhlt)
if (!nhlt)
return 0;
+ if (nhlt->header.length <= sizeof(struct acpi_table_header)) {
+ dev_warn(dev, "Invalid DMIC description table\n");
+ return 0;
+ }
+
for (j = 0, epnt = nhlt->desc; j < nhlt->endpoint_count; j++,
epnt = (struct nhlt_endpoint *)((u8 *)epnt + epnt->length)) {
--
2.26.2