4.4-stable review patch. If anyone has any objections, please let me know.
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From: Kirill Marinushkin k.marinushkin@gmail.com
commit 447cae58cecd69392b74a4a42cd0ab9cabd816af upstream.
The layout of the UAC2 Control request and response varies depending on the request type. With the current implementation, only the Layout 2 Parameter Block (with the 2-byte sized RANGE attribute) is handled properly. For the Control requests with the 1-byte sized RANGE attribute (Bass Control, Mid Control, Tremble Control), the response is parsed incorrectly.
This commit: * fixes the wLength field value in the request * fixes parsing the range values from the response
Fixes: 23caaf19b11e ("ALSA: usb-mixer: Add support for Audio Class v2.0") Signed-off-by: Kirill Marinushkin k.marinushkin@gmail.com Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- sound/usb/mixer.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-)
--- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -343,17 +343,20 @@ static int get_ctl_value_v2(struct usb_m int validx, int *value_ret) { struct snd_usb_audio *chip = cval->head.mixer->chip; - unsigned char buf[4 + 3 * sizeof(__u32)]; /* enough space for one range */ + /* enough space for one range */ + unsigned char buf[sizeof(__u16) + 3 * sizeof(__u32)]; unsigned char *val; - int idx = 0, ret, size; + int idx = 0, ret, val_size, size; __u8 bRequest;
+ val_size = uac2_ctl_value_size(cval->val_type); + if (request == UAC_GET_CUR) { bRequest = UAC2_CS_CUR; - size = uac2_ctl_value_size(cval->val_type); + size = val_size; } else { bRequest = UAC2_CS_RANGE; - size = sizeof(buf); + size = sizeof(__u16) + 3 * val_size; }
memset(buf, 0, sizeof(buf)); @@ -386,16 +389,17 @@ error: val = buf + sizeof(__u16); break; case UAC_GET_MAX: - val = buf + sizeof(__u16) * 2; + val = buf + sizeof(__u16) + val_size; break; case UAC_GET_RES: - val = buf + sizeof(__u16) * 3; + val = buf + sizeof(__u16) + val_size * 2; break; default: return -EINVAL; }
- *value_ret = convert_signed_value(cval, snd_usb_combine_bytes(val, sizeof(__u16))); + *value_ret = convert_signed_value(cval, + snd_usb_combine_bytes(val, val_size));
return 0; }