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

Dmitry Osipenko digetx at gmail.com
Wed Jan 12 20:50:39 CET 2022


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 at vger.kernel.org
Signed-off-by: Dmitry Osipenko <digetx at gmail.com>
---
 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



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