[PATCH 2/2] media: mediatek: vcodec: checking encoder 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>
---
 .../vcodec/encoder/mtk_vcodec_enc_drv.h       |  2 +
 .../mediatek/vcodec/encoder/venc_vpu_if.c     | 40 +++++++++++++++++--
 2 files changed, 38 insertions(+), 4 deletions(-)

diff --git a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
index c07010e56649..a042f607ed8d 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
+++ b/drivers/media/platform/mediatek/vcodec/encoder/mtk_vcodec_enc_drv.h
@@ -123,6 +123,7 @@ struct mtk_enc_params {
  * @xfer_func: enum v4l2_xfer_func, colorspace transfer function
  *
  * @q_mutex: vb2_queue mutex.
+ * @vpu_inst: vpu instance pointer.
  */
 struct mtk_vcodec_enc_ctx {
 	enum mtk_instance_type type;
@@ -156,6 +157,7 @@ struct mtk_vcodec_enc_ctx {
 	enum v4l2_xfer_func xfer_func;
 
 	struct mutex q_mutex;
+	void *vpu_inst;
 };
 
 /**
diff --git a/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c b/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
index 708db1bb32d4..213544e55166 100644
--- a/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
+++ b/drivers/media/platform/mediatek/vcodec/encoder/venc_vpu_if.c
@@ -42,19 +42,47 @@ static void handle_enc_encode_msg(struct venc_vpu_inst *vpu, const void *data)
 	vpu->is_key_frm = msg->is_key_frm;
 }
 
+static bool vpu_enc_check_ap_inst(struct mtk_vcodec_enc_dev *enc_dev, struct venc_vpu_inst *vpu)
+{
+	struct mtk_vcodec_enc_ctx *ctx;
+	int ret = false;
+
+	list_for_each_entry(ctx, &enc_dev->ctx_list, list) {
+		if (!IS_ERR_OR_NULL(ctx) && ctx->vpu_inst == vpu) {
+			ret = true;
+			break;
+		}
+	}
+
+	return ret;
+}
+
 static void vpu_enc_ipi_handler(void *data, unsigned int len, void *priv)
 {
+	struct mtk_vcodec_enc_dev *enc_dev;
 	const struct venc_vpu_ipi_msg_common *msg = data;
-	struct venc_vpu_inst *vpu =
-		(struct venc_vpu_inst *)(unsigned long)msg->venc_inst;
+	struct venc_vpu_inst *vpu;
 
 	mtk_venc_debug(vpu->ctx, "msg_id %x inst %p status %d", msg->msg_id, vpu, msg->status);
 
-	vpu->signaled = 1;
+	enc_dev = (struct mtk_vcodec_enc_dev *)priv;
+	vpu = (struct venc_vpu_inst *)(unsigned long)msg->venc_inst;
+	if (!priv || !vpu) {
+		mtk_v4l2_venc_err(vpu->ctx, "venc_inst is NULL, did the SCP hang or crash?");
+		return;
+	}
+
+	if (!vpu_enc_check_ap_inst(enc_dev, vpu) || msg->msg_id < VPU_IPIMSG_ENC_INIT_DONE ||
+	    msg->msg_id > VPU_IPIMSG_ENC_DEINIT_DONE) {
+		mtk_v4l2_venc_err(vpu->ctx, "venc msg id not correctly => 0x%x", msg->msg_id);
+		vpu->failure = -EINVAL;
+		goto error;
+	}
+
 	vpu->failure = (msg->status != VENC_IPI_MSG_STATUS_OK);
 	if (vpu->failure) {
 		mtk_venc_err(vpu->ctx, "vpu enc status failure %d", vpu->failure);
-		return;
+		goto error;
 	}
 
 	switch (msg->msg_id) {
@@ -72,6 +100,9 @@ static void vpu_enc_ipi_handler(void *data, unsigned int len, void *priv)
 		mtk_venc_err(vpu->ctx, "unknown msg id %x", msg->msg_id);
 		break;
 	}
+
+error:
+	vpu->signaled = 1;
 }
 
 static int vpu_enc_send_msg(struct venc_vpu_inst *vpu, void *msg,
@@ -105,6 +136,7 @@ int vpu_enc_init(struct venc_vpu_inst *vpu)
 	init_waitqueue_head(&vpu->wq_hd);
 	vpu->signaled = 0;
 	vpu->failure = 0;
+	vpu->ctx->vpu_inst = vpu;
 
 	status = mtk_vcodec_fw_ipi_register(vpu->ctx->dev->fw_handler, vpu->id,
 					    vpu_enc_ipi_handler, "venc", NULL);
-- 
2.18.0