hw/audio/virtio-snd: fix invalid param check

Commit 9b6083465f ("virtio-snd: check for invalid param shift
operands") tries to prevent invalid parameters specified by the
guest. However, the code is not correct.

Change the code so that the parameters format and rate, which are
a bit numbers, are compared with the bit size of the data type.

Fixes: 9b6083465f ("virtio-snd: check for invalid param shift operands")
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20240802071805.7123-1-vr_qemu@t-online.de>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
index e5196aa4bb56d98b59a5f86e9f4e33af768b41dc..d1cf5eb445d71bab4cdf03521c2aa1fc2ac92882 100644 (file)
--- a/hw/audio/virtio-snd.c
+++ b/hw/audio/virtio-snd.c
@@ -282,12 +282,12 @@ 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 (BIT(params->format) > sizeof(supported_formats) ||
+    if (params->format >= sizeof(supported_formats) * BITS_PER_BYTE ||
         !(supported_formats & BIT(params->format))) {
         error_report("Stream format is not supported.");
         return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);
     }
-    if (BIT(params->rate) > sizeof(supported_rates) ||
+    if (params->rate >= sizeof(supported_rates) * BITS_PER_BYTE ||
         !(supported_rates & BIT(params->rate))) {
         error_report("Stream rate is not supported.");
         return cpu_to_le32(VIRTIO_SND_S_NOT_SUPP);