[PATCH 2/2] media: venus: fix OOB access issue while reading sequence changed events

[Vedang Nagar <quic_vnagar@xxxxxxxxxxx>]

num_properties_changed is being read from the message queue but is
not validated. Value can be corrupted from the firmware leading to
OOB read access issues. Add fix to read the size of the packets as
well and crosscheck before reading from the packet.

Signed-off-by: Vedang Nagar <quic_vnagar@xxxxxxxxxxx>
---
 drivers/media/platform/qcom/venus/hfi_msgs.c | 62 +++++++++++++++++++++++++++-
 1 file changed, 61 insertions(+), 1 deletion(-)

diff --git a/drivers/media/platform/qcom/venus/hfi_msgs.c b/drivers/media/platform/qcom/venus/hfi_msgs.c
index 0a041b4db9efc549621de07dd13b4a3a37a70d11..3fff21ea744b0171e204dd0851fc46cb468e1979 100644
--- a/drivers/media/platform/qcom/venus/hfi_msgs.c
+++ b/drivers/media/platform/qcom/venus/hfi_msgs.c
@@ -33,8 +33,8 @@ static void event_seq_changed(struct venus_core *core, struct venus_inst *inst,
 	struct hfi_buffer_requirements *bufreq;
 	struct hfi_extradata_input_crop *crop;
 	struct hfi_dpb_counts *dpb_count;
+	u32 ptype, rem_bytes;
 	u8 *data_ptr;
-	u32 ptype;
 
 	inst->error = HFI_ERR_NONE;
 
@@ -56,66 +56,126 @@ static void event_seq_changed(struct venus_core *core, struct venus_inst *inst,
 	}
 
 	data_ptr = (u8 *)&pkt->ext_event_data[0];
+	rem_bytes = pkt->shdr.hdr.size - sizeof(*pkt);
+	if (rem_bytes - 4 < 0) {
+		inst->error = HFI_ERR_SESSION_INSUFFICIENT_RESOURCES;
+		goto done;
+	}
+
 	do {
 		ptype = *((u32 *)data_ptr);
 		switch (ptype) {
 		case HFI_PROPERTY_PARAM_FRAME_SIZE:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_framesize))
+				break;
 			frame_sz = (struct hfi_framesize *)data_ptr;
 			event.width = frame_sz->width;
 			event.height = frame_sz->height;
 			data_ptr += sizeof(*frame_sz);
+			rem_bytes -= sizeof(struct hfi_framesize);
 			break;
 		case HFI_PROPERTY_PARAM_PROFILE_LEVEL_CURRENT:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_profile_level))
+				break;
 			profile_level = (struct hfi_profile_level *)data_ptr;
 			event.profile = profile_level->profile;
 			event.level = profile_level->level;
 			data_ptr += sizeof(*profile_level);
+			rem_bytes -= sizeof(struct hfi_profile_level);
 			break;
 		case HFI_PROPERTY_PARAM_VDEC_PIXEL_BITDEPTH:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_bit_depth))
+				break;
 			pixel_depth = (struct hfi_bit_depth *)data_ptr;
 			event.bit_depth = pixel_depth->bit_depth;
 			data_ptr += sizeof(*pixel_depth);
+			rem_bytes -= sizeof(struct hfi_bit_depth);
 			break;
 		case HFI_PROPERTY_PARAM_VDEC_PIC_STRUCT:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_pic_struct))
+				break;
 			pic_struct = (struct hfi_pic_struct *)data_ptr;
 			event.pic_struct = pic_struct->progressive_only;
 			data_ptr += sizeof(*pic_struct);
+			rem_bytes -= sizeof(struct hfi_pic_struct);
 			break;
 		case HFI_PROPERTY_PARAM_VDEC_COLOUR_SPACE:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_colour_space))
+				break;
 			colour_info = (struct hfi_colour_space *)data_ptr;
 			event.colour_space = colour_info->colour_space;
 			data_ptr += sizeof(*colour_info);
+			rem_bytes -= sizeof(struct hfi_colour_space);
 			break;
 		case HFI_PROPERTY_CONFIG_VDEC_ENTROPY:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(u32))
+				break;
 			event.entropy_mode = *(u32 *)data_ptr;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
 			break;
 		case HFI_PROPERTY_CONFIG_BUFFER_REQUIREMENTS:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_buffer_requirements))
+				break;
 			bufreq = (struct hfi_buffer_requirements *)data_ptr;
 			event.buf_count = hfi_bufreq_get_count_min(bufreq, ver);
 			data_ptr += sizeof(*bufreq);
+			rem_bytes -= sizeof(struct hfi_buffer_requirements);
 			break;
 		case HFI_INDEX_EXTRADATA_INPUT_CROP:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_extradata_input_crop))
+				break;
 			crop = (struct hfi_extradata_input_crop *)data_ptr;
 			event.input_crop.left = crop->left;
 			event.input_crop.top = crop->top;
 			event.input_crop.width = crop->width;
 			event.input_crop.height = crop->height;
 			data_ptr += sizeof(*crop);
+			rem_bytes -= sizeof(struct hfi_extradata_input_crop);
 			break;
 		case HFI_PROPERTY_PARAM_VDEC_DPB_COUNTS:
+			if (rem_bytes < sizeof(u32))
+				break;
 			data_ptr += sizeof(u32);
+			rem_bytes -= sizeof(u32);
+			if (rem_bytes < sizeof(struct hfi_dpb_counts))
+				break;
 			dpb_count = (struct hfi_dpb_counts *)data_ptr;
 			event.buf_count = dpb_count->fw_min_cnt;
 			data_ptr += sizeof(*dpb_count);
+			rem_bytes -= sizeof(struct hfi_dpb_counts);
 			break;
 		default:
 			break;

-- 
2.34.1