[PATCH] spi-imx: prevent overflow when estimating transfer time
Antonio Quartulli
antonio at mandelbit.com
Fri Nov 15 14:02:02 PST 2024
The words delay is computed by multiplying two unsigned ints
and by adding up the result to a u64 variable.
The multiplication, however, is performed with 32bit math
thus losing data when the actual result is larger than UINT32_MAX.
Fix the operation by casting the first operand to u64, thus forcing
the multiplication to be performed with 64bit math.
This fixes 1 OVERFLOW_BEFORE_WIDEN issue reported by Coverity
Report: CID 1601859: Integer handling issues (OVERFLOW_BEFORE_WIDEN)
Cc: Mark Brown <broonie at kernel.org>
Cc: Shawn Guo <shawnguo at kernel.org>
Cc: Sascha Hauer <s.hauer at pengutronix.de>
Cc: Pengutronix Kernel Team <kernel at pengutronix.de>
Cc: Fabio Estevam <festevam at gmail.com>
Cc: imx at lists.linux.dev
Cc: linux-arm-kernel at lists.infradead.org
Cc: linux-kernel at vger.kernel.org
Signed-off-by: Antonio Quartulli <antonio at mandelbit.com>
---
drivers/spi/spi-imx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/spi/spi-imx.c b/drivers/spi/spi-imx.c
index 0b6b0151b3a3..eeb7d082c247 100644
--- a/drivers/spi/spi-imx.c
+++ b/drivers/spi/spi-imx.c
@@ -1685,7 +1685,7 @@ static unsigned int spi_imx_transfer_estimate_time_us(struct spi_transfer *trans
words = DIV_ROUND_UP(transfer->len * BITS_PER_BYTE, transfer->bits_per_word);
word_delay_us = DIV_ROUND_CLOSEST(spi_delay_to_ns(&transfer->word_delay, transfer),
NSEC_PER_USEC);
- result += words * word_delay_us;
+ result += (u64)words * word_delay_us;
}
return min(result, U32_MAX);
--
2.45.2
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