From: Jorge Sanjuan jorge.sanjuan@codethink.co.uk
The control header needs to be read from buffer at this point only in the case of UAC1 protocol. Move it inside the switch case as other protocols such as the Basic Audio Device spec will have an empty buffer that is latter filled as inferred.
Signed-off-by: Jorge Sanjuan jorge.sanjuan@codethink.co.uk [Ruslan: updated with recently added sanity checks] Signed-off-by: Ruslan Bilovol ruslan.bilovol@gmail.com --- sound/usb/card.c | 39 +++++++++++++++++++-------------------- 1 file changed, 19 insertions(+), 20 deletions(-)
diff --git a/sound/usb/card.c b/sound/usb/card.c index 4a1c6bb..4d866bd 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -221,32 +221,13 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif) struct usb_device *dev = chip->dev; struct usb_host_interface *host_iface; struct usb_interface_descriptor *altsd; - void *control_header; int i, protocol; - int rest_bytes;
/* find audiocontrol interface */ host_iface = &usb_ifnum_to_if(dev, ctrlif)->altsetting[0]; - control_header = snd_usb_find_csint_desc(host_iface->extra, - host_iface->extralen, - NULL, UAC_HEADER); altsd = get_iface_desc(host_iface); protocol = altsd->bInterfaceProtocol;
- if (!control_header) { - dev_err(&dev->dev, "cannot find UAC_HEADER\n"); - return -EINVAL; - } - - rest_bytes = (void *)(host_iface->extra + host_iface->extralen) - - control_header; - - /* just to be sure -- this shouldn't hit at all */ - if (rest_bytes <= 0) { - dev_err(&dev->dev, "invalid control header\n"); - return -EINVAL; - } - switch (protocol) { default: dev_warn(&dev->dev, @@ -255,7 +236,25 @@ static int snd_usb_create_streams(struct snd_usb_audio *chip, int ctrlif) /* fall through */
case UAC_VERSION_1: { - struct uac1_ac_header_descriptor *h1 = control_header; + struct uac1_ac_header_descriptor *h1; + int rest_bytes; + + h1 = snd_usb_find_csint_desc(host_iface->extra, + host_iface->extralen, + NULL, UAC_HEADER); + if (!h1) { + dev_err(&dev->dev, "cannot find UAC_HEADER\n"); + return -EINVAL; + } + + rest_bytes = (void *)(host_iface->extra + + host_iface->extralen) - (void *)h1; + + /* just to be sure -- this shouldn't hit at all */ + if (rest_bytes <= 0) { + dev_err(&dev->dev, "invalid control header\n"); + return -EINVAL; + }
if (rest_bytes < sizeof(*h1)) { dev_err(&dev->dev, "too short v1 buffer descriptor\n");