diff options
| -rw-r--r-- | ports/stm32/sdcard.c | 26 |
1 files changed, 19 insertions, 7 deletions
diff --git a/ports/stm32/sdcard.c b/ports/stm32/sdcard.c index a7d062939..eef6548dd 100644 --- a/ports/stm32/sdcard.c +++ b/ports/stm32/sdcard.c @@ -498,13 +498,27 @@ static HAL_StatusTypeDef sdcard_wait_finished(uint32_t timeout) { return HAL_OK; } -mp_uint_t sdcard_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) { +static HAL_StatusTypeDef sdcard_common_checks(uint32_t block_num, uint32_t num_blocks) { // check that SD card is initialised if (!(pyb_sdmmc_flags & PYB_SDMMC_FLAG_ACTIVE)) { return HAL_ERROR; } - HAL_StatusTypeDef err = HAL_OK; + // check that adding block_num & num_blocks don't overflow + // (the ST HAL does a bounds check, but only after adding them...) + uint32_t end_block; + if (__builtin_add_overflow(block_num, num_blocks, &end_block)) { + return HAL_ERROR; + } + + return HAL_OK; +} + +mp_uint_t sdcard_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blocks) { + HAL_StatusTypeDef err = sdcard_common_checks(block_num, num_blocks); + if (err != HAL_OK) { + return err; + } // check that dest pointer is aligned on a 4-byte boundary uint8_t *orig_dest = NULL; @@ -595,13 +609,11 @@ mp_uint_t sdcard_read_blocks(uint8_t *dest, uint32_t block_num, uint32_t num_blo } mp_uint_t sdcard_write_blocks(const uint8_t *src, uint32_t block_num, uint32_t num_blocks) { - // check that SD card is initialised - if (!(pyb_sdmmc_flags & PYB_SDMMC_FLAG_ACTIVE)) { - return HAL_ERROR; + HAL_StatusTypeDef err = sdcard_common_checks(block_num, num_blocks); + if (err != HAL_OK) { + return err; } - HAL_StatusTypeDef err = HAL_OK; - // check that src pointer is aligned on a 4-byte boundary if (((uint32_t)src & 3) != 0) { // pointer is not aligned, so allocate a temporary block to do the write |