diff --git a/examples/device/cdc_msc_freertos/src/msc_disk.c b/examples/device/cdc_msc_freertos/src/msc_disk.c
index d2f8628f13..f48d976f23 100644
--- a/examples/device/cdc_msc_freertos/src/msc_disk.c
+++ b/examples/device/cdc_msc_freertos/src/msc_disk.c
@@ -191,7 +191,9 @@ int32_t tud_msc_read10_cb(uint8_t lun, uint32_t lba, uint32_t offset, void* buff
 
   // out of ramdisk
   if ( lba >= DISK_BLOCK_NUM ) return -1;
-
+  // Check for overflow of offset + bufsize
+  if ( offset + bufsize >= DISK_BLOCK_SIZE ) return -1;
+  
   uint8_t const* addr = msc_disk[lba] + offset;
   memcpy(buffer, addr, bufsize);