timer: stm32f2xx_timer: add check for prescaler value

The STM32F2XX Timer emulator uses a 16 bit prescaler value to
limit the timer clock rate. It does that by dividing the timer
frequency. If the prescaler 's->tim_psc' was set to be UINT_MAX,
it'd lead to divide by zero error. Limit prescaler value to 16
bits to avoid it.

Reported-by: Huawei PSIRT <psirt@huawei.com>
Signed-off-by: Prasad J Pandit <pjp@fedoraproject.org>
Message-id: 1476800269-31902-1-git-send-email-ppandit@redhat.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Prasad J Pandit 2016-10-24 16:26:55 +01:00 committed by Peter Maydell
parent 0fa758c3a0
commit 84da15169b
1 changed files with 1 additions and 1 deletions

View File

@ -217,7 +217,7 @@ static void stm32f2xx_timer_write(void *opaque, hwaddr offset,
return;
case TIM_PSC:
timer_val = stm32f2xx_ns_to_ticks(s, now) - s->tick_offset;
s->tim_psc = value;
s->tim_psc = value & 0xFFFF;
value = timer_val;
break;
case TIM_CNT: