Re: [PATCH v2 4/6] virtio-snd: don't allocate pcm_info zero-count buf

[Jim MacArthur <jim.macarthur@linaro.org>]

On Tue, Nov 10, 2026 at 02:39:33PM +0200, Manos Pitsidianakis wrote:
> g_new0() might return NULL, which is UB if passed to a memcpy
> implementation that does not expect it (not in the usual case).
> 
> Resolves: https://gitlab.com/qemu-project/qemu/-/work_items/3778
> Signed-off-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
> ---
>  hw/audio/virtio-snd.c | 5 +++++
>  1 file changed, 5 insertions(+)
> 
> diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
> index 89406f0a3a..a7d749f24f 100644
> --- a/hw/audio/virtio-snd.c
> +++ b/hw/audio/virtio-snd.c
> @@ -267,6 +267,11 @@ static void virtio_snd_handle_pcm_info(VirtIOSound *s,
>          return;
>      }
>  
> +    if (count == 0) {
> +        cmd->payload_size = 0;
> +        cmd->resp.code = cpu_to_le32(VIRTIO_SND_S_OK);
> +        return;
> +    }
>      pcm_info = g_new0(virtio_snd_pcm_info, count);
>      for (uint32_t i = 0; i < count; i++) {
>          stream_id = i + start_id;
> 
> -- 
> 2.56.0
> 
> 

Reviewed-by: Jim MacArthur <jim.macarthur@linaro.org>