1 files changed, 57 insertions, 16 deletions

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 7498b5191b68..eceab19766db 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -68,6 +68,7 @@ struct mixer_build {
 	unsigned char *buffer;
 	unsigned int buflen;
 	DECLARE_BITMAP(unitbitmap, MAX_ID_ELEMS);
+	DECLARE_BITMAP(termbitmap, MAX_ID_ELEMS);
 	struct usb_audio_term oterm;
 	const struct usbmix_name_map *map;
 	const struct usbmix_selector_map *selector_map;
@@ -738,12 +739,13 @@ static int uac_mixer_unit_get_channels(struct mixer_build *state,
 				       struct uac_mixer_unit_descriptor *desc)
 {
 	int mu_channels;
-	void *c;
 
 	if (desc->bLength < sizeof(*desc))
 		return -EINVAL;
 	if (!desc->bNrInPins)
 		return -EINVAL;
+	if (desc->bLength < sizeof(*desc) + desc->bNrInPins)
+		return -EINVAL;
 
 	switch (state->mixer->protocol) {
 	case UAC_VERSION_1:
@@ -759,13 +761,6 @@ static int uac_mixer_unit_get_channels(struct mixer_build *state,
 		break;
 	}
 
-	if (!mu_channels)
-		return 0;
-
-	c = uac_mixer_unit_bmControls(desc, state->mixer->protocol);
-	if (c - (void *)desc + (mu_channels - 1) / 8 >= desc->bLength)
-		return 0; /* no bmControls -> skip */
-
 	return mu_channels;
 }
 
@@ -773,16 +768,25 @@ static int uac_mixer_unit_get_channels(struct mixer_build *state,
  * parse the source unit recursively until it reaches to a terminal
  * or a branched unit.
  */
-static int check_input_term(struct mixer_build *state, int id,
+static int __check_input_term(struct mixer_build *state, int id,
 			    struct usb_audio_term *term)
 {
 	int protocol = state->mixer->protocol;
 	int err;
 	void *p1;
+	unsigned char *hdr;
 
 	memset(term, 0, sizeof(*term));
-	while ((p1 = find_audio_control_unit(state, id)) != NULL) {
-		unsigned char *hdr = p1;
+	for (;;) {
+		/* a loop in the terminal chain? */
+		if (test_and_set_bit(id, state->termbitmap))
+			return -EINVAL;
+
+		p1 = find_audio_control_unit(state, id);
+		if (!p1)
+			break;
+
+		hdr = p1;
 		term->id = id;
 
 		if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
@@ -800,7 +804,7 @@ static int check_input_term(struct mixer_build *state, int id,
 
 					/* call recursively to verify that the
 					 * referenced clock entity is valid */
-					err = check_input_term(state, d->bCSourceID, term);
+					err = __check_input_term(state, d->bCSourceID, term);
 					if (err < 0)
 						return err;
 
@@ -834,7 +838,7 @@ static int check_input_term(struct mixer_build *state, int id,
 			case UAC2_CLOCK_SELECTOR: {
 				struct uac_selector_unit_descriptor *d = p1;
 				/* call recursively to retrieve the channel info */
-				err = check_input_term(state, d->baSourceID[0], term);
+				err = __check_input_term(state, d->baSourceID[0], term);
 				if (err < 0)
 					return err;
 				term->type = UAC3_SELECTOR_UNIT << 16; /* virtual type */
@@ -897,7 +901,7 @@ static int check_input_term(struct mixer_build *state, int id,
 
 				/* call recursively to verify that the
 				 * referenced clock entity is valid */
-				err = check_input_term(state, d->bCSourceID, term);
+				err = __check_input_term(state, d->bCSourceID, term);
 				if (err < 0)
 					return err;
 
@@ -948,7 +952,7 @@ static int check_input_term(struct mixer_build *state, int id,
 			case UAC3_CLOCK_SELECTOR: {
 				struct uac_selector_unit_descriptor *d = p1;
 				/* call recursively to retrieve the channel info */
-				err = check_input_term(state, d->baSourceID[0], term);
+				err = __check_input_term(state, d->baSourceID[0], term);
 				if (err < 0)
 					return err;
 				term->type = UAC3_SELECTOR_UNIT << 16; /* virtual type */
@@ -964,7 +968,7 @@ static int check_input_term(struct mixer_build *state, int id,
 					return -EINVAL;
 
 				/* call recursively to retrieve the channel info */
-				err = check_input_term(state, d->baSourceID[0], term);
+				err = __check_input_term(state, d->baSourceID[0], term);
 				if (err < 0)
 					return err;
 
@@ -982,6 +986,15 @@ static int check_input_term(struct mixer_build *state, int id,
 	return -ENODEV;
 }
 
+
+static int check_input_term(struct mixer_build *state, int id,
+			    struct usb_audio_term *term)
+{
+	memset(term, 0, sizeof(*term));
+	memset(state->termbitmap, 0, sizeof(state->termbitmap));
+	return __check_input_term(state, id, term);
+}
+
 /*
  * Feature Unit
  */
@@ -1988,6 +2001,31 @@ static int parse_audio_feature_unit(struct mixer_build *state, int unitid,
  * Mixer Unit
  */
 
+/* check whether the given in/out overflows bmMixerControls matrix */
+static bool mixer_bitmap_overflow(struct uac_mixer_unit_descriptor *desc,
+				  int protocol, int num_ins, int num_outs)
+{
+	u8 *hdr = (u8 *)desc;
+	u8 *c = uac_mixer_unit_bmControls(desc, protocol);
+	size_t rest; /* remaining bytes after bmMixerControls */
+
+	switch (protocol) {
+	case UAC_VERSION_1:
+	default:
+		rest = 1; /* iMixer */
+		break;
+	case UAC_VERSION_2:
+		rest = 2; /* bmControls + iMixer */
+		break;
+	case UAC_VERSION_3:
+		rest = 6; /* bmControls + wMixerDescrStr */
+		break;
+	}
+
+	/* overflow? */
+	return c + (num_ins * num_outs + 7) / 8 + rest > hdr + hdr[0];
+}
+
 /*
  * build a mixer unit control
  *
@@ -2116,6 +2154,9 @@ static int parse_audio_mixer_unit(struct mixer_build *state, int unitid,
 		if (err < 0)
 			return err;
 		num_ins += iterm.channels;
+		if (mixer_bitmap_overflow(desc, state->mixer->protocol,
+					  num_ins, num_outs))
+			break;
 		for (; ich < num_ins; ich++) {
 			int och, ich_has_controls = 0;