add assert to prevent div by zero

1 files changed, 6 insertions, 2 deletions

diff --git a/src/class/msc/msc_device.c b/src/class/msc/msc_device.c
index a77282ed5..115ca1432 100644
--- a/src/class/msc/msc_device.c
+++ b/src/class/msc/msc_device.c
@@ -583,10 +583,14 @@ static void proc_read10_cmd(uint8_t rhport, mscd_interface_t* p_msc)
   msc_cbw_t const * p_cbw = &p_msc->cbw;

   msc_csw_t       * p_csw = &p_msc->csw;

 

-  uint16_t const block_sz = p_cbw->total_bytes / rdwr10_get_blockcount(p_cbw->command);

+  uint16_t const block_cnt = rdwr10_get_blockcount(p_cbw->command);

+  TU_ASSERT(block_cnt, ); // prevent div by zero

+

+  uint16_t const block_sz = p_cbw->total_bytes / block_cnt;

+  TU_ASSERT(block_sz, ); // prevent div by zero

 

   // Adjust lba with transferred bytes

-  uint32_t const lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);

+  uint32_t lba = rdwr10_get_lba(p_cbw->command) + (p_msc->xferred_len / block_sz);

 

   // remaining bytes capped at class buffer

   int32_t nbytes = (int32_t) tu_min32(sizeof(_mscd_buf), p_cbw->total_bytes-p_msc->xferred_len);