[PATCH v1] ASoC: hdmi-codec: Fix OOB memory accesses

From: Dmitry Osipenko
Date: Wed Jan 12 2022 - 14:53:50 EST


Correct size of iec_status array by changing it to the size of status
array of the struct snd_aes_iec958. This fixes out-of-bounds slab
read accesses made by memcpy() of the hdmi-codec driver. This problem
is reported by KASAN.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dmitry Osipenko <digetx@xxxxxxxxx>
---
include/uapi/sound/asound.h | 4 +++-
sound/soc/codecs/hdmi-codec.c | 2 +-
2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/include/uapi/sound/asound.h b/include/uapi/sound/asound.h
index ef0cafe295b2..2d3e5df39a59 100644
--- a/include/uapi/sound/asound.h
+++ b/include/uapi/sound/asound.h
@@ -56,8 +56,10 @@
* *
****************************************************************************/

+#define AES_IEC958_STATUS_SIZE 24
+
struct snd_aes_iec958 {
- unsigned char status[24]; /* AES/IEC958 channel status bits */
+ unsigned char status[AES_IEC958_STATUS_SIZE]; /* AES/IEC958 channel status bits */
unsigned char subcode[147]; /* AES/IEC958 subcode bits */
unsigned char pad; /* nothing */
unsigned char dig_subframe[4]; /* AES/IEC958 subframe bits */
diff --git a/sound/soc/codecs/hdmi-codec.c b/sound/soc/codecs/hdmi-codec.c
index b61f980cabdc..b07607a9ecea 100644
--- a/sound/soc/codecs/hdmi-codec.c
+++ b/sound/soc/codecs/hdmi-codec.c
@@ -277,7 +277,7 @@ struct hdmi_codec_priv {
bool busy;
struct snd_soc_jack *jack;
unsigned int jack_status;
- u8 iec_status[5];
+ u8 iec_status[AES_IEC958_STATUS_SIZE];
};

static const struct snd_soc_dapm_widget hdmi_widgets[] = {
--
2.33.1