4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx> commit c45fcf46ca2368dafe7e5c513a711a6f0f974308 upstream. If period_ns is small, prd might well become 0. Catch that case because otherwise with regmap_write(priv->regmap, TIM_ARR, prd - 1); a few lines down quite a big period is configured. Fixes: 7edf7369205b ("pwm: Add driver for STM32 plaftorm") Cc: stable@xxxxxxxxxxxxxxx Reviewed-by: Trevor Gamblin <tgamblin@xxxxxxxxxxxx> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/b86f62f099983646f97eeb6bfc0117bb2d0c340d.1718979150.git.u.kleine-koenig@xxxxxxxxxxxx Signed-off-by: Uwe Kleine-König <ukleinek@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/pwm/pwm-stm32.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -337,6 +337,9 @@ static int stm32_pwm_config(struct stm32 prd = div; + if (!prd) + return -EINVAL; + if (prescaler > MAX_TIM_PSC) return -EINVAL;