From f0a353b4d184b36a68e3d6951b5027a0c6c0c526 Mon Sep 17 00:00:00 2001 From: Colin Ian King Date: Fri, 1 Nov 2019 10:00:35 +0000 Subject: drivers: thermal: tsens: fix potential integer overflow on multiply Currently a multiply operation is being performed on two int values and the result is being assigned to a u64, presumably because the end result is expected to be probably larger than an int. However, because the multiply is an int multiply one can get overflow. Avoid the overflow by casting degc to a u64 to force a u64 multiply. Also use div_u64 for the divide as suggested by Daniel Lezcano. Addresses-Coverity: ("Unintentional integer overflow") Fixes: fbfe1a042cfd ("drivers: thermal: tsens: Add interrupt support") Signed-off-by: Colin Ian King Signed-off-by: Daniel Lezcano Reviewed-by: Amit Kucheria Link: https://lore.kernel.org/r/20191101100035.25502-1-colin.king@canonical.com --- drivers/thermal/qcom/tsens-common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/thermal') diff --git a/drivers/thermal/qcom/tsens-common.c b/drivers/thermal/qcom/tsens-common.c index 4359a4247ac3..c8d57ee0a5bb 100644 --- a/drivers/thermal/qcom/tsens-common.c +++ b/drivers/thermal/qcom/tsens-common.c @@ -92,7 +92,7 @@ void compute_intercept_slope(struct tsens_priv *priv, u32 *p1, static inline u32 degc_to_code(int degc, const struct tsens_sensor *s) { - u64 code = (degc * s->slope + s->offset) / SLOPE_FACTOR; + u64 code = div_u64(((u64)degc * s->slope + s->offset), SLOPE_FACTOR); pr_debug("%s: raw_code: 0x%llx, degc:%d\n", __func__, code, degc); return clamp_val(code, THRESHOLD_MIN_ADC_CODE, THRESHOLD_MAX_ADC_CODE); -- cgit v1.2.3