[PATCH 3.19 025/175] ASoC: Intel: sst: Fix firmware name size handling

[Greg Kroah-Hartman]

3.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Christian Engelmayer <cengelma@xxxxxx>

commit 279e17ae81c17b40ae7a6c9e10f386a7aac7aa55 upstream.

Function sst_acpi_probe() uses plain strcpy for setting member firmware_name
of a struct intel_sst_drv from member firmware of a struct sst_machines.
Thereby the destination array has got a length of 20 byte while the source may
hold 32 byte. Since eg. commit 64b9c90b8600 ("ASoC: Intel: Fix BYTCR firmware
name") increased strings from "fw_sst_0f28.bin" to "intel/fw_sst_0f28.bin"
there is an actual possibility that the 20 byte array at the end of struct
intel_sst_drv is overrun.

Thus increase the size of the destination and use the same define for both
structs. Detected by Coverity CID 1260087.

Signed-off-by: Christian Engelmayer <cengelma@xxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 sound/soc/intel/sst/sst.h      |    3 ++-
 sound/soc/intel/sst/sst_acpi.c |    2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

--- a/sound/soc/intel/sst/sst.h
+++ b/sound/soc/intel/sst/sst.h
@@ -58,6 +58,7 @@ enum sst_algo_ops {
 #define SST_BLOCK_TIMEOUT	1000
 
 #define FW_SIGNATURE_SIZE	4
+#define FW_NAME_SIZE		32
 
 /* stream states */
 enum sst_stream_states {
@@ -426,7 +427,7 @@ struct intel_sst_drv {
 	 * Holder for firmware name. Due to async call it needs to be
 	 * persistent till worker thread gets called
 	 */
-	char firmware_name[20];
+	char firmware_name[FW_NAME_SIZE];
 };
 
 /* misc definitions */
--- a/sound/soc/intel/sst/sst_acpi.c
+++ b/sound/soc/intel/sst/sst_acpi.c
@@ -47,7 +47,7 @@ struct sst_machines {
 	char board[32];
 	char machine[32];
 	void (*machine_quirk)(void);
-	char firmware[32];
+	char firmware[FW_NAME_SIZE];
 	struct sst_platform_info *pdata;
 
 };


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