[PATCH v2,1/2] media: mediatek: vcodec: checking decoder ack message parameter

[Yunfei Dong]

Need to checking all parameters of msg data are valid or not,
in case of access null pointer or unreasonable value leading
to kernel reboot.

Signed-off-by: Yunfei Dong <yunfei.dong at mediatek.com>
Reviewed-by: Nicolas Dufresne <nicolas.dufresne at collabora.com>
---
 .../vcodec/decoder/mtk_vcodec_dec_drv.h       |  2 +
 .../mediatek/vcodec/decoder/vdec_vpu_if.c     | 77 ++++++++++++-------
 2 files changed, 52 insertions(+), 27 deletions(-)

diff --git a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
index 6c318de25a55..7e36b2c69b7d 100644
--- a/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
+++ b/drivers/media/platform/mediatek/vcodec/decoder/mtk_vcodec_dec_drv.h
@@ -161,6 +161,7 @@ struct mtk_vcodec_dec_pdata {
  * @hw_id: hardware index used to identify different hardware.
  *
  * @msg_queue: msg queue used to store lat buffer information.
+ * @vpu_inst: vpu instance pointer.
  *
  * @is_10bit_bitstream: set to true if it's 10bit bitstream
  */
@@ -205,6 +206,7 @@ struct mtk_vcodec_dec_ctx {
 	int hw_id;
 
 	struct vdec_msg_queue msg_queue;
+	void *vpu_inst;
 
 	bool is_10bit_bitstream;
 };
diff --git a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
index 82c3dc8c4127..23cfe5c6c90b 100644
--- a/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
+++ b/drivers/media/platform/mediatek/vcodec/decoder/vdec_vpu_if.c
@@ -72,6 +72,21 @@ static void handle_get_param_msg_ack(const struct vdec_vpu_ipi_get_param_ack *ms
 	}
 }
 
+static bool vpu_dec_check_ap_inst(struct mtk_vcodec_dec_dev *dec_dev, struct vdec_vpu_inst *vpu)
+{
+	struct mtk_vcodec_dec_ctx *ctx;
+	int ret = false;
+
+	list_for_each_entry(ctx, &dec_dev->ctx_list, list) {
+		if (!IS_ERR_OR_NULL(ctx) && ctx->vpu_inst == vpu) {
+			ret = true;
+			break;
+		}
+	}
+
+	return ret;
+}
+
 /*
  * vpu_dec_ipi_handler - Handler for VPU ipi message.
  *
@@ -84,44 +99,51 @@ static void handle_get_param_msg_ack(const struct vdec_vpu_ipi_get_param_ack *ms
  */
 static void vpu_dec_ipi_handler(void *data, unsigned int len, void *priv)
 {
+	struct mtk_vcodec_dec_dev *dec_dev;
 	const struct vdec_vpu_ipi_ack *msg = data;
-	struct vdec_vpu_inst *vpu = (struct vdec_vpu_inst *)
-					(unsigned long)msg->ap_inst_addr;
+	struct vdec_vpu_inst *vpu;
 
-	if (!vpu) {
+	dec_dev = (struct mtk_vcodec_dec_dev *)priv;
+	vpu = (struct vdec_vpu_inst *)(unsigned long)msg->ap_inst_addr;
+	if (!priv || !vpu) {
 		mtk_v4l2_vdec_err(vpu->ctx, "ap_inst_addr is NULL, did the SCP hang or crash?");
 		return;
 	}
 
-	mtk_vdec_debug(vpu->ctx, "+ id=%X", msg->msg_id);
+	if (!vpu_dec_check_ap_inst(dec_dev, vpu) || msg->msg_id < VPU_IPIMSG_DEC_INIT_ACK ||
+	    msg->msg_id > VPU_IPIMSG_DEC_GET_PARAM_ACK) {
+		mtk_v4l2_vdec_err(vpu->ctx, "vdec msg id not correctly => 0x%x", msg->msg_id);
+		vpu->failure = -EINVAL;
+		goto error;
+	}
 
 	vpu->failure = msg->status;
-	vpu->signaled = 1;
+	if (msg->status != 0)
+		goto error;
 
-	if (msg->status == 0) {
-		switch (msg->msg_id) {
-		case VPU_IPIMSG_DEC_INIT_ACK:
-			handle_init_ack_msg(data);
-			break;
+	switch (msg->msg_id) {
+	case VPU_IPIMSG_DEC_INIT_ACK:
+		handle_init_ack_msg(data);
+		break;
 
-		case VPU_IPIMSG_DEC_START_ACK:
-		case VPU_IPIMSG_DEC_END_ACK:
-		case VPU_IPIMSG_DEC_DEINIT_ACK:
-		case VPU_IPIMSG_DEC_RESET_ACK:
-		case VPU_IPIMSG_DEC_CORE_ACK:
-		case VPU_IPIMSG_DEC_CORE_END_ACK:
-			break;
+	case VPU_IPIMSG_DEC_START_ACK:
+	case VPU_IPIMSG_DEC_END_ACK:
+	case VPU_IPIMSG_DEC_DEINIT_ACK:
+	case VPU_IPIMSG_DEC_RESET_ACK:
+	case VPU_IPIMSG_DEC_CORE_ACK:
+	case VPU_IPIMSG_DEC_CORE_END_ACK:
+		break;
 
-		case VPU_IPIMSG_DEC_GET_PARAM_ACK:
-			handle_get_param_msg_ack(data);
-			break;
-		default:
-			mtk_vdec_err(vpu->ctx, "invalid msg=%X", msg->msg_id);
-			break;
-		}
+	case VPU_IPIMSG_DEC_GET_PARAM_ACK:
+		handle_get_param_msg_ack(data);
+		break;
+	default:
+		mtk_vdec_err(vpu->ctx, "invalid msg=%X", msg->msg_id);
+		break;
 	}
 
-	mtk_vdec_debug(vpu->ctx, "- id=%X", msg->msg_id);
+error:
+	vpu->signaled = 1;
 }
 
 static int vcodec_vpu_send_msg(struct vdec_vpu_inst *vpu, void *msg, int len)
@@ -182,9 +204,10 @@ int vpu_dec_init(struct vdec_vpu_inst *vpu)
 
 	init_waitqueue_head(&vpu->wq);
 	vpu->handler = vpu_dec_ipi_handler;
+	vpu->ctx->vpu_inst = vpu;
 
 	err = mtk_vcodec_fw_ipi_register(vpu->ctx->dev->fw_handler, vpu->id,
-					 vpu->handler, "vdec", NULL);
+					 vpu->handler, "vdec", vpu->ctx->dev);
 	if (err) {
 		mtk_vdec_err(vpu->ctx, "vpu_ipi_register fail status=%d", err);
 		return err;
@@ -193,7 +216,7 @@ int vpu_dec_init(struct vdec_vpu_inst *vpu)
 	if (vpu->ctx->dev->vdec_pdata->hw_arch == MTK_VDEC_LAT_SINGLE_CORE) {
 		err = mtk_vcodec_fw_ipi_register(vpu->ctx->dev->fw_handler,
 						 vpu->core_id, vpu->handler,
-						 "vdec", NULL);
+						 "vdec", vpu->ctx->dev);
 		if (err) {
 			mtk_vdec_err(vpu->ctx, "vpu_ipi_register core fail status=%d", err);
 			return err;
-- 
2.18.0