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Re: [Qemu-devel] [PATCH v2] char: serial: check divider value against ba
From: |
Paolo Bonzini |
Subject: |
Re: [Qemu-devel] [PATCH v2] char: serial: check divider value against baud base |
Date: |
Wed, 12 Oct 2016 10:13:27 +0200 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.3.0 |
On 12/10/2016 07:58, P J P wrote:
> From: Prasad J Pandit <address@hidden>
>
> 16550A UART device uses an oscillator to generate frequencies
> (baud base), which decide communication speed. This speed could
> be changed by dividing it by a divider. If the divider is
> greater than the baud base, speed is set to zero, leading to a
> divide by zero error. Add check to avoid it.
>
> Reported-by: Huawei PSIRT <address@hidden>
> Signed-off-by: Prasad J Pandit <address@hidden>
> ---
> hw/char/serial.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> Update per
> -> https://lists.gnu.org/archive/html/qemu-devel/2016-10/msg02400.html
>
> diff --git a/hw/char/serial.c b/hw/char/serial.c
> index 3442f47..eec72b7 100644
> --- a/hw/char/serial.c
> +++ b/hw/char/serial.c
> @@ -153,8 +153,9 @@ static void serial_update_parameters(SerialState *s)
> int speed, parity, data_bits, stop_bits, frame_size;
> QEMUSerialSetParams ssp;
>
> - if (s->divider == 0)
> + if (s->divider == 0 || s->divider > s->baudbase) {
> return;
> + }
>
> /* Start bit. */
> frame_size = 1;
>
Queued, thanks.
Paolo