diff --git a/drivers/media/platform/amphion/vpu_core.c b/drivers/media/platform/amphion/vpu_core.c
index 968b578700e3..a5dcb4abf954 100644
--- a/drivers/media/platform/amphion/vpu_core.c
+++ b/drivers/media/platform/amphion/vpu_core.c
@@ -472,7 +472,7 @@ struct vpu_inst *vpu_core_find_instance(struct vpu_core *core, u32 index)
 	struct vpu_inst *tmp;
 
 	mutex_lock(&core->lock);
-	if (!test_bit(index, &core->instance_mask))
+	if (index >= core->supported_instance_count || !test_bit(index, &core->instance_mask))
 		goto exit;
 	list_for_each_entry(tmp, &core->instances, list) {
 		if (tmp->id == index) {
diff --git a/drivers/media/platform/amphion/vpu_helpers.c b/drivers/media/platform/amphion/vpu_helpers.c
index 768abf89e606..e9aeb3453dfc 100644
--- a/drivers/media/platform/amphion/vpu_helpers.c
+++ b/drivers/media/platform/amphion/vpu_helpers.c
@@ -197,7 +197,7 @@ u32 vpu_helper_get_plane_size(u32 fmt, u32 w, u32 h, int plane_no,
 	}
 }
 
-u32 vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
 				       u32 *rptr, u32 size, void *dst)
 {
 	u32 offset;
@@ -227,10 +227,11 @@ u32 vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
 	}
 
 	*rptr = vpu_helper_step_walk(stream_buffer, offset, size);
-	return size;
+
+	return 0;
 }
 
-u32 vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
 				     u32 *wptr, u32 size, void *src)
 {
 	u32 offset;
@@ -260,10 +261,10 @@ u32 vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
 
 	*wptr = vpu_helper_step_walk(stream_buffer, offset, size);
 
-	return size;
+	return 0;
 }
 
-u32 vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
 				    u32 *wptr, u8 val, u32 size)
 {
 	u32 offset;
@@ -297,7 +298,7 @@ u32 vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
 
 	*wptr = offset;
 
-	return size;
+	return 0;
 }
 
 u32 vpu_helper_get_free_space(struct vpu_inst *inst)
diff --git a/drivers/media/platform/amphion/vpu_helpers.h b/drivers/media/platform/amphion/vpu_helpers.h
index 130d1357c032..bc28350958be 100644
--- a/drivers/media/platform/amphion/vpu_helpers.h
+++ b/drivers/media/platform/amphion/vpu_helpers.h
@@ -19,11 +19,11 @@ u32 vpu_helper_valid_frame_width(struct vpu_inst *inst, u32 width);
 u32 vpu_helper_valid_frame_height(struct vpu_inst *inst, u32 height);
 u32 vpu_helper_get_plane_size(u32 fmt, u32 width, u32 height, int plane_no,
 			      u32 stride, u32 interlaced, u32 *pbl);
-u32 vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_copy_from_stream_buffer(struct vpu_buffer *stream_buffer,
 				       u32 *rptr, u32 size, void *dst);
-u32 vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_copy_to_stream_buffer(struct vpu_buffer *stream_buffer,
 				     u32 *wptr, u32 size, void *src);
-u32 vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
+int vpu_helper_memset_stream_buffer(struct vpu_buffer *stream_buffer,
 				    u32 *wptr, u8 val, u32 size);
 u32 vpu_helper_get_free_space(struct vpu_inst *inst);
 u32 vpu_helper_get_used_space(struct vpu_inst *inst);
diff --git a/drivers/media/platform/amphion/vpu_imx8q.c b/drivers/media/platform/amphion/vpu_imx8q.c
index 606cc53125f8..f14c2b8312a8 100644
--- a/drivers/media/platform/amphion/vpu_imx8q.c
+++ b/drivers/media/platform/amphion/vpu_imx8q.c
@@ -165,7 +165,7 @@ int vpu_imx8q_on_firmware_loaded(struct vpu_core *core)
 	return 0;
 }
 
-u32 vpu_imx8q_check_memory_region(dma_addr_t base, dma_addr_t addr, u32 size)
+int vpu_imx8q_check_memory_region(dma_addr_t base, dma_addr_t addr, u32 size)
 {
 	const struct vpu_rpc_region_t imx8q_regions[] = {
 		{0x00000000, 0x08000000, VPU_CORE_MEMORY_CACHED},
diff --git a/drivers/media/platform/amphion/vpu_imx8q.h b/drivers/media/platform/amphion/vpu_imx8q.h
index d63a2747e29c..9deffd7dde42 100644
--- a/drivers/media/platform/amphion/vpu_imx8q.h
+++ b/drivers/media/platform/amphion/vpu_imx8q.h
@@ -108,7 +108,7 @@ int vpu_imx8q_set_system_cfg_common(struct vpu_rpc_system_config *config, u32 re
 int vpu_imx8q_boot_core(struct vpu_core *core);
 int vpu_imx8q_get_power_state(struct vpu_core *core);
 int vpu_imx8q_on_firmware_loaded(struct vpu_core *core);
-u32 vpu_imx8q_check_memory_region(dma_addr_t base, dma_addr_t addr, u32 size);
+int vpu_imx8q_check_memory_region(dma_addr_t base, dma_addr_t addr, u32 size);
 bool vpu_imx8q_check_codec(enum vpu_core_type type);
 bool vpu_imx8q_check_fmt(enum vpu_core_type type, u32 pixelfmt);
 
diff --git a/drivers/media/platform/amphion/vpu_malone.c b/drivers/media/platform/amphion/vpu_malone.c
index d9cecbb42b2a..1212f7919957 100644
--- a/drivers/media/platform/amphion/vpu_malone.c
+++ b/drivers/media/platform/amphion/vpu_malone.c
@@ -1006,8 +1006,8 @@ static int vpu_malone_add_padding_scode(struct vpu_buffer *stream_buffer,
 					u32 pixelformat, u32 scode_type)
 {
 	u32 wptr;
-	u32 size;
-	u32 total_size = 0;
+	int size;
+	int total_size = 0;
 	const struct malone_padding_scode *ps;
 	const u32 padding_size = 4096;
 	int ret;
@@ -1024,7 +1024,7 @@ static int vpu_malone_add_padding_scode(struct vpu_buffer *stream_buffer,
 
 	size = sizeof(ps->data);
 	ret = vpu_helper_copy_to_stream_buffer(stream_buffer, &wptr, size, (void *)ps->data);
-	if (ret < size)
+	if (ret < 0)
 		return -EINVAL;
 	total_size += size;
 
@@ -1234,12 +1234,15 @@ static int vpu_malone_insert_scode_seq(struct malone_scode_t *scode, u32 codec_i
 					       &scode->wptr,
 					       sizeof(hdr),
 					       hdr);
-	return ret;
+	if (ret < 0)
+		return ret;
+	return sizeof(hdr);
 }
 
 static int vpu_malone_insert_scode_pic(struct malone_scode_t *scode, u32 codec_id, u32 ext_size)
 {
 	u8 hdr[MALONE_PAYLOAD_HEADER_SIZE];
+	int ret;
 
 	set_payload_hdr(hdr,
 			SCODE_PICTURE,
@@ -1247,10 +1250,13 @@ static int vpu_malone_insert_scode_pic(struct malone_scode_t *scode, u32 codec_i
 			ext_size + vb2_get_plane_payload(scode->vb, 0),
 			scode->inst->out_format.width,
 			scode->inst->out_format.height);
-	return vpu_helper_copy_to_stream_buffer(&scode->inst->stream_buffer,
-						&scode->wptr,
-						sizeof(hdr),
-						hdr);
+	ret = vpu_helper_copy_to_stream_buffer(&scode->inst->stream_buffer,
+					       &scode->wptr,
+					       sizeof(hdr),
+					       hdr);
+	if (ret < 0)
+		return ret;
+	return sizeof(hdr);
 }
 
 static int vpu_malone_insert_scode_vc1_g_pic(struct malone_scode_t *scode)
@@ -1258,6 +1264,7 @@ static int vpu_malone_insert_scode_vc1_g_pic(struct malone_scode_t *scode)
 	struct vb2_v4l2_buffer *vbuf;
 	u8 nal_hdr[MALONE_VC1_NAL_HEADER_LEN];
 	u32 *data = NULL;
+	int ret;
 
 	vbuf = to_vb2_v4l2_buffer(scode->vb);
 	data = vb2_plane_vaddr(scode->vb, 0);
@@ -1268,10 +1275,13 @@ static int vpu_malone_insert_scode_vc1_g_pic(struct malone_scode_t *scode)
 		return 0;
 
 	create_vc1_nal_pichdr(nal_hdr);
-	return vpu_helper_copy_to_stream_buffer(&scode->inst->stream_buffer,
-						&scode->wptr,
-						sizeof(nal_hdr),
-						nal_hdr);
+	ret = vpu_helper_copy_to_stream_buffer(&scode->inst->stream_buffer,
+					       &scode->wptr,
+					       sizeof(nal_hdr),
+					       nal_hdr);
+	if (ret < 0)
+		return ret;
+	return sizeof(nal_hdr);
 }
 
 static int vpu_malone_insert_scode_vc1_l_seq(struct malone_scode_t *scode)
@@ -1282,8 +1292,7 @@ static int vpu_malone_insert_scode_vc1_l_seq(struct malone_scode_t *scode)
 
 	scode->need_data = 0;
 
-	ret = vpu_malone_insert_scode_seq(scode, MALONE_CODEC_ID_VC1_SIMPLE,
-					  sizeof(rcv_seqhdr));
+	ret = vpu_malone_insert_scode_seq(scode, MALONE_CODEC_ID_VC1_SIMPLE, sizeof(rcv_seqhdr));
 	if (ret < 0)
 		return ret;
 	size = ret;
@@ -1299,7 +1308,7 @@ static int vpu_malone_insert_scode_vc1_l_seq(struct malone_scode_t *scode)
 
 	if (ret < 0)
 		return ret;
-	size += ret;
+	size += sizeof(rcv_seqhdr);
 	return size;
 }
 
@@ -1322,7 +1331,7 @@ static int vpu_malone_insert_scode_vc1_l_pic(struct malone_scode_t *scode)
 					       rcv_pichdr);
 	if (ret < 0)
 		return ret;
-	size += ret;
+	size += sizeof(rcv_pichdr);
 	return size;
 }
 
@@ -1346,7 +1355,7 @@ static int vpu_malone_insert_scode_vp8_seq(struct malone_scode_t *scode)
 					       ivf_hdr);
 	if (ret < 0)
 		return ret;
-	size += ret;
+	size += sizeof(ivf_hdr);
 
 	return size;
 }
@@ -1369,7 +1378,7 @@ static int vpu_malone_insert_scode_vp8_pic(struct malone_scode_t *scode)
 					       ivf_hdr);
 	if (ret < 0)
 		return ret;
-	size += ret;
+	size += sizeof(ivf_hdr);
 
 	return size;
 }
@@ -1470,9 +1479,9 @@ static int vpu_malone_input_frame_data(struct vpu_malone_str_buffer __iomem *str
 					       &wptr,
 					       vb2_get_plane_payload(vb, 0),
 					       vb2_plane_vaddr(vb, 0));
-	if (ret < vb2_get_plane_payload(vb, 0))
+	if (ret < 0)
 		return -ENOMEM;
-	size += ret;
+	size += vb2_get_plane_payload(vb, 0);
 
 	vpu_malone_update_wptr(str_buf, wptr);
 
@@ -1500,7 +1509,7 @@ static int vpu_malone_input_stream_data(struct vpu_malone_str_buffer __iomem *st
 					       &wptr,
 					       vb2_get_plane_payload(vb, 0),
 					       vb2_plane_vaddr(vb, 0));
-	if (ret < vb2_get_plane_payload(vb, 0))
+	if (ret < 0)
 		return -ENOMEM;
 
 	vpu_malone_update_wptr(str_buf, wptr);
@@ -1566,9 +1575,13 @@ static bool vpu_malone_check_ready(struct vpu_shared_addr *shared, u32 instance)
 	u32 size = desc->end - desc->start;
 	u32 rptr = desc->rptr;
 	u32 wptr = desc->wptr;
-	u32 used = (wptr + size - rptr) % size;
+	u32 used;
+
+	if (!size)
+		return true;
 
-	if (!size || used < (size >> 1))
+	used = (wptr + size - rptr) % size;
+	if (used < (size >> 1))
 		return true;
 
 	return false;
diff --git a/drivers/media/platform/amphion/vpu_msgs.c b/drivers/media/platform/amphion/vpu_msgs.c
index 68df43913904..58502c51ddb3 100644
--- a/drivers/media/platform/amphion/vpu_msgs.c
+++ b/drivers/media/platform/amphion/vpu_msgs.c
@@ -214,7 +214,7 @@ static int vpu_session_handle_msg(struct vpu_inst *inst, struct vpu_rpc_event *m
 
 static bool vpu_inst_receive_msg(struct vpu_inst *inst, struct vpu_rpc_event *pkt)
 {
-	u32 bytes = sizeof(struct vpu_rpc_event_header);
+	unsigned long bytes = sizeof(struct vpu_rpc_event_header);
 	u32 ret;
 
 	memset(pkt, 0, sizeof(*pkt));
@@ -246,7 +246,7 @@ void vpu_inst_run_work(struct work_struct *work)
 
 static void vpu_inst_handle_msg(struct vpu_inst *inst, struct vpu_rpc_event *pkt)
 {
-	u32 bytes;
+	unsigned long bytes;
 	u32 id = pkt->hdr.id;
 	int ret;
 
@@ -337,7 +337,7 @@ void vpu_msg_delayed_work(struct work_struct *work)
 {
 	struct vpu_core *core;
 	struct delayed_work *dwork;
-	u32 bytes = sizeof(bytes);
+	unsigned long bytes = sizeof(u32);
 	u32 i;
 
 	if (!work)
diff --git a/drivers/media/platform/amphion/vpu_rpc.c b/drivers/media/platform/amphion/vpu_rpc.c
index 6e01abaa5d16..18a164766409 100644
--- a/drivers/media/platform/amphion/vpu_rpc.c
+++ b/drivers/media/platform/amphion/vpu_rpc.c
@@ -20,7 +20,7 @@
 #include "vpu_windsor.h"
 #include "vpu_malone.h"
 
-u32 vpu_iface_check_memory_region(struct vpu_core *core, dma_addr_t addr, u32 size)
+int vpu_iface_check_memory_region(struct vpu_core *core, dma_addr_t addr, u32 size)
 {
 	struct vpu_iface_ops *ops = vpu_core_get_iface(core);
 
@@ -63,6 +63,8 @@ static int vpu_rpc_send_cmd_buf(struct vpu_shared_addr *shared, struct vpu_rpc_e
 	u32 wptr;
 	u32 i;
 
+	if (cmd->hdr.num > 0xff || cmd->hdr.num >= ARRAY_SIZE(cmd->data))
+		return -EINVAL;
 	desc = shared->cmd_desc;
 	space = vpu_rpc_check_buffer_space(desc, true);
 	if (space < (((cmd->hdr.num + 1) << 2) + 16))
diff --git a/drivers/media/platform/amphion/vpu_rpc.h b/drivers/media/platform/amphion/vpu_rpc.h
index c764ff52d026..5ea4f8aff846 100644
--- a/drivers/media/platform/amphion/vpu_rpc.h
+++ b/drivers/media/platform/amphion/vpu_rpc.h
@@ -43,7 +43,7 @@ struct vpu_iface_ops {
 	bool (*check_codec)(enum vpu_core_type type);
 	bool (*check_fmt)(enum vpu_core_type type, u32 pixelfmt);
 	u32 (*get_data_size)(void);
-	u32 (*check_memory_region)(dma_addr_t base, dma_addr_t addr, u32 size);
+	int (*check_memory_region)(dma_addr_t base, dma_addr_t addr, u32 size);
 	int (*boot_core)(struct vpu_core *core);
 	int (*shutdown_core)(struct vpu_core *core);
 	int (*restore_core)(struct vpu_core *core);
@@ -113,7 +113,7 @@ struct vpu_rpc_region_t {
 
 struct vpu_iface_ops *vpu_core_get_iface(struct vpu_core *core);
 struct vpu_iface_ops *vpu_inst_get_iface(struct vpu_inst *inst);
-u32 vpu_iface_check_memory_region(struct vpu_core *core, dma_addr_t addr, u32 size);
+int vpu_iface_check_memory_region(struct vpu_core *core, dma_addr_t addr, u32 size);
 
 static inline bool vpu_iface_check_codec(struct vpu_core *core)
 {
diff --git a/drivers/media/platform/amphion/vpu_v4l2.c b/drivers/media/platform/amphion/vpu_v4l2.c
index 6fe077a685e8..9c0704cd5766 100644
--- a/drivers/media/platform/amphion/vpu_v4l2.c
+++ b/drivers/media/platform/amphion/vpu_v4l2.c
@@ -403,11 +403,15 @@ void vpu_vb2_buffers_return(struct vpu_inst *inst, unsigned int type, enum vb2_b
 	struct vb2_v4l2_buffer *buf;
 
 	if (V4L2_TYPE_IS_OUTPUT(type)) {
-		while ((buf = v4l2_m2m_src_buf_remove(inst->fh.m2m_ctx)))
+		while ((buf = v4l2_m2m_src_buf_remove(inst->fh.m2m_ctx))) {
+			vpu_set_buffer_state(buf, VPU_BUF_STATE_IDLE);
 			v4l2_m2m_buf_done(buf, state);
+		}
 	} else {
-		while ((buf = v4l2_m2m_dst_buf_remove(inst->fh.m2m_ctx)))
+		while ((buf = v4l2_m2m_dst_buf_remove(inst->fh.m2m_ctx))) {
+			vpu_set_buffer_state(buf, VPU_BUF_STATE_IDLE);
 			v4l2_m2m_buf_done(buf, state);
+		}
 	}
 }
 
diff --git a/drivers/media/platform/amphion/vpu_windsor.c b/drivers/media/platform/amphion/vpu_windsor.c
index a056ad624e9b..1526af2ef9da 100644
--- a/drivers/media/platform/amphion/vpu_windsor.c
+++ b/drivers/media/platform/amphion/vpu_windsor.c
@@ -818,12 +818,18 @@ int vpu_windsor_config_memory_resource(struct vpu_shared_addr *shared,
 
 	switch (type) {
 	case MEM_RES_ENC:
+		if (index >= ARRAY_SIZE(pool->enc_frames))
+			return -EINVAL;
 		res = &pool->enc_frames[index];
 		break;
 	case MEM_RES_REF:
+		if (index >= ARRAY_SIZE(pool->ref_frames))
+			return -EINVAL;
 		res = &pool->ref_frames[index];
 		break;
 	case MEM_RES_ACT:
+		if (index)
+			return -EINVAL;
 		res = &pool->act_frame;
 		break;
 	default:
