fix(flash): Check for I/O failure during firmware file reading

Author: JakubVanek

src/bl_install.c

@@ -261,9 +261,15 @@ static int bootloader_send(FILE *fp, int length, u32* pCrc32)
 int bootloader_crc(FILE *fp, u32 starting_sector, u32 num_sectors, bool verbose)
 {
 	u8 *firmware = calloc(FLASH_SIZE, 1);
-	int read_bytes = fread(firmware, 1, FLASH_SIZE, fp);
-	if (read_bytes != FLASH_SIZE) {
-		printf("WARNING: firmware file might be truncated: %d bytes expected, %d bytes read\n", FLASH_SIZE, read_bytes);
+	u32 read_bytes = fread(firmware, 1, FLASH_SIZE, fp);
+	if (ferror(fp)) {
+		errmsg = "Reading of firmware file failed";
+		free(firmware);
+		return ERR_IO;
+	}
+	u32 wanted_bytes = (starting_sector + num_sectors) * FLASH_SECTOR_SIZE;
+	if (read_bytes < wanted_bytes) {
+		printf("WARNING: firmware file is truncated: %d bytes expected, %d bytes read\n", wanted_bytes, read_bytes);
 	}
 
 	int err = ERR_UNK;