From: Mark Pearson markpearson@lenovo.com

[ Upstream commit a14a6219996ee6f6e858d83b11affc7907633687 ]

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 Signed-off-by: Sasha Levin sashal@kernel.org --- 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 baeda6c9716a..6ed80a4cba01 100644 --- a/sound/hda/intel-nhlt.c +++ b/sound/hda/intel-nhlt.c @@ -72,6 +72,11 @@ 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)) {