1 files changed, 44 insertions, 12 deletions

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 91bc8f18791e..9afb8ab524c7 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -204,6 +204,10 @@ static int snd_usb_copy_string_desc(struct mixer_build *state,
 				    int index, char *buf, int maxlen)
 {
 	int len = usb_string(state->chip->dev, index, buf, maxlen - 1);
+
+	if (len < 0)
+		return 0;
+
 	buf[len] = 0;
 	return len;
 }
@@ -652,10 +656,14 @@ static int get_term_name(struct mixer_build *state, struct usb_audio_term *iterm
 			 unsigned char *name, int maxlen, int term_only)
 {
 	struct iterm_name_combo *names;
+	int len;
 
-	if (iterm->name)
-		return snd_usb_copy_string_desc(state, iterm->name,
+	if (iterm->name) {
+		len = snd_usb_copy_string_desc(state, iterm->name,
 						name, maxlen);
+		if (len)
+			return len;
+	}
 
 	/* virtual type - not a real terminal */
 	if (iterm->type >> 16) {
@@ -1469,6 +1477,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
 	__u8 *bmaControls;
 
 	if (state->mixer->protocol == UAC_VERSION_1) {
+		if (hdr->bLength < 7) {
+			usb_audio_err(state->chip,
+				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
+				      unitid);
+			return -EINVAL;
+		}
 		csize = hdr->bControlSize;
 		if (!csize) {
 			usb_audio_dbg(state->chip,
@@ -1486,6 +1500,12 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
 		}
 	} else {
 		struct uac2_feature_unit_descriptor *ftr = _ftr;
+		if (hdr->bLength < 6) {
+			usb_audio_err(state->chip,
+				      "unit %u: invalid UAC_FEATURE_UNIT descriptor\n",
+				      unitid);
+			return -EINVAL;
+		}
 		csize = 4;
 		channels = (hdr->bLength - 6) / 4 - 1;
 		bmaControls = ftr->bmaControls;
@@ -2086,7 +2106,8 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
 	const struct usbmix_name_map *map;
 	char **namelist;
 
-	if (!desc->bNrInPins || desc->bLength < 5 + desc->bNrInPins) {
+	if (desc->bLength < 5 || !desc->bNrInPins ||
+	    desc->bLength < 5 + desc->bNrInPins) {
 		usb_audio_err(state->chip,
 			"invalid SELECTOR UNIT descriptor %d\n", unitid);
 		return -EINVAL;
@@ -2156,19 +2177,25 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
 	kctl->private_value = (unsigned long)namelist;
 	kctl->private_free = usb_mixer_selector_elem_free;
 
-	nameid = uac_selector_unit_iSelector(desc);
+	/* check the static mapping table at first */
 	len = check_mapped_name(map, kctl->id.name, sizeof(kctl->id.name));
-	if (len)
-		;
-	else if (nameid)
-		snd_usb_copy_string_desc(state, nameid, kctl->id.name,
-					 sizeof(kctl->id.name));
-	else {
-		len = get_term_name(state, &state->oterm,
+	if (!len) {
+		/* no mapping ? */
+		/* if iSelector is given, use it */
+		nameid = uac_selector_unit_iSelector(desc);
+		if (nameid)
+			len = snd_usb_copy_string_desc(state, nameid,
+						       kctl->id.name,
+						       sizeof(kctl->id.name));
+		/* ... or pick up the terminal name at next */
+		if (!len)
+			len = get_term_name(state, &state->oterm,
 				    kctl->id.name, sizeof(kctl->id.name), 0);
+		/* ... or use the fixed string "USB" as the last resort */
 		if (!len)
 			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
 
+		/* and add the proper suffix */
 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
 			append_ctl_name(kctl, " Clock Source");
 		else if ((state->oterm.type & 0xff00) == 0x0100)
@@ -2330,9 +2357,14 @@ void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid)
 {
 	struct usb_mixer_elem_list *list;
 
-	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem)
+	for (list = mixer->id_elems[unitid]; list; list = list->next_id_elem) {
+		struct usb_mixer_elem_info *info =
+			(struct usb_mixer_elem_info *)list;
+		/* invalidate cache, so the value is read from the device */
+		info->cached = 0;
 		snd_ctl_notify(mixer->chip->card, SNDRV_CTL_EVENT_MASK_VALUE,
 			       &list->kctl->id);
+	}
 }
 
 static void snd_usb_mixer_dump_cval(struct snd_info_buffer *buffer,