[alsa-devel] [PATCH 01/11] ASoC: Intel: Skylake: Fix the memory overwrite of tlv buffer

[Vinod Koul]

TLV buffer can be smaller than the module data, so update the
size of data to be copied before doing the copy.

Also TLV header consists of two unsigned ints, this is also taken
into account here and size modified to reflect this

Suggested-by: Takashi Iwai <tiwai at suse.de>
Signed-off-by: Vinod Koul <vinod.koul at intel.com>
---
 sound/soc/intel/skylake/skl-topology.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/sound/soc/intel/skylake/skl-topology.c b/sound/soc/intel/skylake/skl-topology.c
index 4624556f486d..d1ddfdac22fe 100644
--- a/sound/soc/intel/skylake/skl-topology.c
+++ b/sound/soc/intel/skylake/skl-topology.c
@@ -916,6 +916,13 @@ static int skl_tplg_tlv_control_get(struct snd_kcontrol *kcontrol,
 		skl_get_module_params(skl->skl_sst, (u32 *)bc->params,
 				      bc->max, bc->param_id, mconfig);
 
+	/* decrement size for TLV header */
+	size -= 2 * sizeof(u32);
+
+	/* check size as we don't want to send kernel data */
+	if (size > bc->max)
+		size = bc->max;
+
 	if (bc->params) {
 		if (copy_to_user(data, &bc->param_id, sizeof(u32)))
 			return -EFAULT;
-- 
1.9.1