diff --git a/src/ext_manifest.c b/src/ext_manifest.c
index 9624156..99b77f2 100644
--- a/src/ext_manifest.c
+++ b/src/ext_manifest.c
@@ -25,7 +25,8 @@ const struct ext_man_header ext_man_template = {
 static int ext_man_open_file(struct image *image)
 {
 	/* open extended manifest outfile for writing */
-	sprintf(image->out_ext_man_file, "%s.xman", image->out_file);
+	snprintf(image->out_ext_man_file, sizeof(image->out_ext_man_file),
+			 "%s.xman", image->out_file);
 	unlink(image->out_ext_man_file);
 
 	image->out_ext_man_fd = fopen(image->out_ext_man_file, "wb");
diff --git a/src/file_simple.c b/src/file_simple.c
index 3c34496..50f3f13 100644
--- a/src/file_simple.c
+++ b/src/file_simple.c
@@ -128,6 +128,11 @@ static int simple_write_module(struct image *image, struct module *module)
 
 	/* Get the pointer of writing hdr */
 	ptr_hdr = ftell(image->out_fd);
+	if (ptr_hdr < 0) {
+		fprintf(stderr, "error: cant get file position\n");
+		return -errno;
+	}
+
 	count = fwrite(&hdr, sizeof(hdr), 1, image->out_fd);
 	if (count != 1) {
 		fprintf(stderr, "error: failed to write section header %d\n",
@@ -172,15 +177,28 @@ static int simple_write_module(struct image *image, struct module *module)
 	hdr.size += padding;
 	/* Record current pointer, will set it back after overwriting hdr */
 	ptr_cur = ftell(image->out_fd);
+	if (ptr_cur < 0) {
+		fprintf(stderr, "error: cant get file position\n");
+		return -errno;
+	}
 	/* overwrite hdr */
-	fseek(image->out_fd, ptr_hdr, SEEK_SET);
+	err = fseek(image->out_fd, ptr_hdr, SEEK_SET);
+	if (err) {
+		fprintf(stderr, "cant seek %d\n", -errno);
+		return -errno;
+	}
+
 	count = fwrite(&hdr, sizeof(hdr), 1, image->out_fd);
 	if (count != 1) {
 		fprintf(stderr, "error: failed to write section header %d\n",
 			-errno);
 		return -errno;
 	}
-	fseek(image->out_fd, ptr_cur, SEEK_SET);
+	err = fseek(image->out_fd, ptr_cur, SEEK_SET);
+	if (err) {
+		fprintf(stderr, "cant seek %d\n", -errno);
+		return -errno;
+	}
 
 	fprintf(stdout, "\n");
 	/* return padding size */
@@ -324,7 +342,12 @@ int simple_write_firmware(struct image *image)
 		hdr.file_size += ret;
 	}
 	/* overwrite hdr */
-	fseek(image->out_fd, 0, SEEK_SET);
+	ret = fseek(image->out_fd, 0, SEEK_SET);
+	if (ret) {
+		fprintf(stderr, "cant seek %d\n", -errno);
+		return -errno;
+	}
+
 	count = fwrite(&hdr, sizeof(hdr), 1, image->out_fd);
 	if (count != 1)
 		return -errno;
diff --git a/src/manifest.c b/src/manifest.c
index d3d7f26..7e52efe 100644
--- a/src/manifest.c
+++ b/src/manifest.c
@@ -27,7 +27,8 @@ static int man_open_rom_file(struct image *image)
 {
 	uint32_t size;
 
-	sprintf(image->out_rom_file, "%s.rom", image->out_file);
+	snprintf(image->out_rom_file, sizeof(image->out_rom_file),
+			 "%s.rom", image->out_file);
 	unlink(image->out_rom_file);
 
 	size = image->adsp->mem_zones[SOF_FW_BLK_TYPE_ROM].size;
@@ -50,7 +51,8 @@ static int man_open_rom_file(struct image *image)
 
 static int man_open_unsigned_file(struct image *image)
 {
-	sprintf(image->out_unsigned_file, "%s.uns", image->out_file);
+	snprintf(image->out_unsigned_file, sizeof(image->out_unsigned_file),
+			 "%s.uns", image->out_file);
 	unlink(image->out_unsigned_file);
 
 	/* open unsigned FW outfile for writing */
@@ -67,7 +69,8 @@ static int man_open_unsigned_file(struct image *image)
 static int man_open_manifest_file(struct image *image)
 {
 	/* open manifest outfile for writing */
-	sprintf(image->out_man_file, "%s.met", image->out_file);
+	snprintf(image->out_man_file, sizeof(image->out_man_file),
+			 "%s.met", image->out_file);
 	unlink(image->out_man_file);
 
 	image->out_man_fd = fopen(image->out_man_file, "wb");
@@ -1361,10 +1364,10 @@ int man_write_fw_v2_5(struct image *image)
 int verify_image(struct image *image)
 {
 	FILE *in_file;
-	int ret, i;
+	int ret = 0;
 	long size;
 	void *buffer;
-	size_t read;
+	size_t read, i;
 
 	/* is verify supported for target ? */
 	if (!image->adsp->verify_firmware) {
@@ -1432,7 +1435,7 @@ int verify_image(struct image *image)
 		image->verify_file);
 out:
 	fclose(in_file);
-	return 0;
+	return ret;
 }
 
 
@@ -1440,7 +1443,8 @@ int resign_image(struct image *image)
 {
 	int key_size, key_file_size;
 	void *buffer = NULL;
-	size_t size, read;
+	size_t read;
+	int32_t size;
 	FILE *in_file;
 	int ret, i;
 
@@ -1487,7 +1491,7 @@ int resign_image(struct image *image)
 	/* read file into buffer */
 	read = fread(buffer, 1, size, in_file);
 	if (read != size) {
-		fprintf(stderr, "error: unable to read %zu bytes from %s err %d\n",
+		fprintf(stderr, "error: unable to read %d bytes from %s err %d\n",
 					size, image->in_file, errno);
 		ret = errno;
 		goto out;
diff --git a/src/rimage.c b/src/rimage.c
index c7b112d..f24aed9 100644
--- a/src/rimage.c
+++ b/src/rimage.c
@@ -160,7 +160,8 @@ int main(int argc, char *argv[])
 
 	if (image.in_file) {
 		fprintf(stdout, "going to re-sign\n");
-		return resign_image(&image);
+		ret = resign_image(&image);
+		goto out;
 	}
 
 	/* set IMR Type in found machine definition */