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>
(cherry picked from commit 7d14471a121878602cb4e748c4707f9ab9a9e3e2)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/hw/audio/virtio-snd.c b/hw/audio/virtio-snd.c
index 2b80072b042b1df9827948c3dbff008b568ff6ac..95f55a02f1871710a4e33da841385da643e909f5 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);