> From: Manos Pitsidianakis <manos.pitsidiana...@linaro.org>
>
> When setting the parameters of a PCM stream, we compute the bit flag
> with the format and rate values as shift operand to check if they are
> set in supported_formats and supported_rates.
>
> If the guest provides a format/rate value which when shifting 1 results
> in a value bigger than the number of bits in
> supported_formats/supported_rates, we must report an error.
>
> Previously, this ended up triggering the not reached assertions later
> when converting to internal QEMU values.
>
> Reported-by: Zheyu Ma <zheyum...@gmail.com>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2416
> Signed-off-by: Manos Pitsidianakis <manos.pitsidiana...@linaro.org>
> Message-Id: <virtio-snd-fuzz-2416-fix-v1-manos.pitsidiana...@linaro.org>
> Reviewed-by: Philippe Mathieu-Daudé <phi...@linaro.org>
> Reviewed-by: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
> ---
> hw/audio/virtio-snd.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
> index e6432ac959..e5196aa4bb 100644
> --- a/hw/audio/virtio-snd.c
> +++ b/hw/audio/virtio-snd.c
> @@ -282,11 +282,13 @@ uint32_t virtio_snd_set_pcm_params(VirtIOSound *s,
> error_report("Number of channels is not supported.");
> return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
> }
> - if (!(supported_formats & BIT(params->format))) {
Hi Manos,
this patch doesn't work as intended. I guess you wanted to write
if (params->format >= sizeof(supported_formats) * BITS_PER_BYTE ||
!(supported_formats & BIT(params->format))) {
> + if (BIT(params->format) > sizeof(supported_formats) ||
> + !(supported_formats & BIT(params->format))) {
> error_report("Stream format is not supported.");
> return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
> }
> - if (!(supported_rates & BIT(params->rate))) {
if (params->rate >= sizeof(supported_rates) * BITS_PER_BYTE ||
!(supported_rates & BIT(params->rate))) {
With best regards,
Volker
> + if (BIT(params->rate) > sizeof(supported_rates) ||
> + !(supported_rates & BIT(params->rate))) {
> error_report("Stream rate is not supported.");
> return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
> }
