diff --git a/sound/usb/validate.c b/sound/usb/validate.c
new file mode 100644
index 0000000..389e865
--- /dev/null
+++ b/sound/usb/validate.c
@@ -0,0 +1,332 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+//
+// Validation of USB-audio class descriptors
+//
+
+#include <linux/init.h>
+#include <linux/usb.h>
+#include <linux/usb/audio.h>
+#include <linux/usb/audio-v2.h>
+#include <linux/usb/audio-v3.h>
+#include <linux/usb/midi.h>
+#include "usbaudio.h"
+#include "helper.h"
+
+struct usb_desc_validator {
+	unsigned char protocol;
+	unsigned char type;
+	bool (*func)(const void *p, const struct usb_desc_validator *v);
+	size_t size;
+};
+
+#define UAC_VERSION_ALL		(unsigned char)(-1)
+
+/* UAC1 only */
+static bool validate_uac1_header(const void *p,
+				 const struct usb_desc_validator *v)
+{
+	const struct uac1_ac_header_descriptor *d = p;
+
+	return d->bLength >= sizeof(*d) &&
+		d->bLength >= sizeof(*d) + d->bInCollection;
+}
+
+/* for mixer unit; covering all UACs */
+static bool validate_mixer_unit(const void *p,
+				const struct usb_desc_validator *v)
+{
+	const struct uac_mixer_unit_descriptor *d = p;
+	size_t len;
+
+	if (d->bLength < sizeof(*d) || !d->bNrInPins)
+		return false;
+	len = sizeof(*d) + d->bNrInPins;
+	/* We can't determine the bitmap size only from this unit descriptor,
+	 * so just check with the remaining length.
+	 * The actual bitmap is checked at mixer unit parser.
+	 */
+	switch (v->protocol) {
+	case UAC_VERSION_1:
+	default:
+		len += 2 + 1; /* wChannelConfig, iChannelNames */
+		/* bmControls[n*m] */
+		len += 1; /* iMixer */
+		break;
+	case UAC_VERSION_2:
+		len += 4 + 1; /* bmChannelConfig, iChannelNames */
+		/* bmMixerControls[n*m] */
+		len += 1 + 1; /* bmControls, iMixer */
+		break;
+	case UAC_VERSION_3:
+		len += 2; /* wClusterDescrID */
+		/* bmMixerControls[n*m] */
+		break;
+	}
+	return d->bLength >= len;
+}
+
+/* both for processing and extension units; covering all UACs */
+static bool validate_processing_unit(const void *p,
+				     const struct usb_desc_validator *v)
+{
+	const struct uac_processing_unit_descriptor *d = p;
+	const unsigned char *hdr = p;
+	size_t len, m;
+
+	if (d->bLength < sizeof(*d))
+		return false;
+	len = sizeof(*d) + d->bNrInPins;
+	if (d->bLength < len)
+		return false;
+	switch (v->protocol) {
+	case UAC_VERSION_1:
+	default:
+		/* bNrChannels, wChannelConfig, iChannelNames */
+		len += 1 + 2 + 1;
+		if (d->bLength < len + 1) /* bControlSize */
+			return false;
+		m = hdr[len];
+		len += 1 + m + 1; /* bControlSize, bmControls, iProcessing */
+		break;
+	case UAC_VERSION_2:
+		/* bNrChannels, bmChannelConfig, iChannelNames */
+		len += 1 + 4 + 1;
+		if (v->type == UAC2_PROCESSING_UNIT_V2)
+			len += 2; /* bmControls -- 2 bytes for PU */
+		else
+			len += 1; /* bmControls -- 1 byte for EU */
+		len += 1; /* iProcessing */
+		break;
+	case UAC_VERSION_3:
+		/* wProcessingDescrStr, bmControls */
+		len += 2 + 4;
+		break;
+	}
+	if (d->bLength < len)
+		return false;
+
+	switch (v->protocol) {
+	case UAC_VERSION_1:
+	default:
+		if (v->type == UAC1_EXTENSION_UNIT)
+			return true; /* OK */
+		switch (d->wProcessType) {
+		case UAC_PROCESS_UP_DOWNMIX:
+		case UAC_PROCESS_DOLBY_PROLOGIC:
+			if (d->bLength < len + 1) /* bNrModes */
+				return false;
+			m = hdr[len];
+			len += 1 + m * 2; /* bNrModes, waModes(n) */
+			break;
+		default:
+			break;
+		}
+		break;
+	case UAC_VERSION_2:
+		if (v->type == UAC2_EXTENSION_UNIT_V2)
+			return true; /* OK */
+		switch (d->wProcessType) {
+		case UAC2_PROCESS_UP_DOWNMIX:
+		case UAC2_PROCESS_DOLBY_PROLOCIC: /* SiC! */
+			if (d->bLength < len + 1) /* bNrModes */
+				return false;
+			m = hdr[len];
+			len += 1 + m * 4; /* bNrModes, daModes(n) */
+			break;
+		default:
+			break;
+		}
+		break;
+	case UAC_VERSION_3:
+		if (v->type == UAC3_EXTENSION_UNIT) {
+			len += 2; /* wClusterDescrID */
+			break;
+		}
+		switch (d->wProcessType) {
+		case UAC3_PROCESS_UP_DOWNMIX:
+			if (d->bLength < len + 1) /* bNrModes */
+				return false;
+			m = hdr[len];
+			len += 1 + m * 2; /* bNrModes, waClusterDescrID(n) */
+			break;
+		case UAC3_PROCESS_MULTI_FUNCTION:
+			len += 2 + 4; /* wClusterDescrID, bmAlgorighms */
+			break;
+		default:
+			break;
+		}
+		break;
+	}
+	if (d->bLength < len)
+		return false;
+
+	return true;
+}
+
+/* both for selector and clock selector units; covering all UACs */
+static bool validate_selector_unit(const void *p,
+				   const struct usb_desc_validator *v)
+{
+	const struct uac_selector_unit_descriptor *d = p;
+	size_t len;
+
+	if (d->bLength < sizeof(*d))
+		return false;
+	len = sizeof(*d) + d->bNrInPins;
+	switch (v->protocol) {
+	case UAC_VERSION_1:
+	default:
+		len += 1; /* iSelector */
+		break;
+	case UAC_VERSION_2:
+		len += 1 + 1; /* bmControls, iSelector */
+		break;
+	case UAC_VERSION_3:
+		len += 4 + 2; /* bmControls, wSelectorDescrStr */
+		break;
+	}
+	return d->bLength >= len;
+}
+
+static bool validate_uac1_feature_unit(const void *p,
+				       const struct usb_desc_validator *v)
+{
+	const struct uac_feature_unit_descriptor *d = p;
+
+	if (d->bLength < sizeof(*d) || !d->bControlSize)
+		return false;
+	/* at least bmaControls(0) for master channel + iFeature */
+	return d->bLength >= sizeof(*d) + d->bControlSize + 1;
+}
+
+static bool validate_uac2_feature_unit(const void *p,
+				       const struct usb_desc_validator *v)
+{
+	const struct uac2_feature_unit_descriptor *d = p;
+
+	if (d->bLength < sizeof(*d))
+		return false;
+	/* at least bmaControls(0) for master channel + iFeature */
+	return d->bLength >= sizeof(*d) + 4 + 1;
+}
+
+static bool validate_uac3_feature_unit(const void *p,
+				       const struct usb_desc_validator *v)
+{
+	const struct uac3_feature_unit_descriptor *d = p;
+
+	if (d->bLength < sizeof(*d))
+		return false;
+	/* at least bmaControls(0) for master channel + wFeatureDescrStr */
+	return d->bLength >= sizeof(*d) + 4 + 2;
+}
+
+static bool validate_midi_out_jack(const void *p,
+				   const struct usb_desc_validator *v)
+{
+	const struct usb_midi_out_jack_descriptor *d = p;
+
+	return d->bLength >= sizeof(*d) &&
+		d->bLength >= sizeof(*d) + d->bNrInputPins * 2;
+}
+
+#define FIXED(p, t, s) { .protocol = (p), .type = (t), .size = sizeof(s) }
+#define FUNC(p, t, f) { .protocol = (p), .type = (t), .func = (f) }
+
+static struct usb_desc_validator audio_validators[] = {
+	/* UAC1 */
+	FUNC(UAC_VERSION_1, UAC_HEADER, validate_uac1_header),
+	FIXED(UAC_VERSION_1, UAC_INPUT_TERMINAL,
+	      struct uac_input_terminal_descriptor),
+	FIXED(UAC_VERSION_1, UAC_OUTPUT_TERMINAL,
+	      struct uac1_output_terminal_descriptor),
+	FUNC(UAC_VERSION_1, UAC_MIXER_UNIT, validate_mixer_unit),
+	FUNC(UAC_VERSION_1, UAC_SELECTOR_UNIT, validate_selector_unit),
+	FUNC(UAC_VERSION_1, UAC_FEATURE_UNIT, validate_uac1_feature_unit),
+	FUNC(UAC_VERSION_1, UAC1_PROCESSING_UNIT, validate_processing_unit),
+	FUNC(UAC_VERSION_1, UAC1_EXTENSION_UNIT, validate_processing_unit),
+
+	/* UAC2 */
+	FIXED(UAC_VERSION_2, UAC_HEADER, struct uac2_ac_header_descriptor),
+	FIXED(UAC_VERSION_2, UAC_INPUT_TERMINAL,
+	      struct uac2_input_terminal_descriptor),
+	FIXED(UAC_VERSION_2, UAC_OUTPUT_TERMINAL,
+	      struct uac2_output_terminal_descriptor),
+	FUNC(UAC_VERSION_2, UAC_MIXER_UNIT, validate_mixer_unit),
+	FUNC(UAC_VERSION_2, UAC_SELECTOR_UNIT, validate_selector_unit),
+	FUNC(UAC_VERSION_2, UAC_FEATURE_UNIT, validate_uac2_feature_unit),
+	/* UAC_VERSION_2, UAC2_EFFECT_UNIT: not implemented yet */
+	FUNC(UAC_VERSION_2, UAC2_PROCESSING_UNIT_V2, validate_processing_unit),
+	FUNC(UAC_VERSION_2, UAC2_EXTENSION_UNIT_V2, validate_processing_unit),
+	FIXED(UAC_VERSION_2, UAC2_CLOCK_SOURCE,
+	      struct uac_clock_source_descriptor),
+	FUNC(UAC_VERSION_2, UAC2_CLOCK_SELECTOR, validate_selector_unit),
+	FIXED(UAC_VERSION_2, UAC2_CLOCK_MULTIPLIER,
+	      struct uac_clock_multiplier_descriptor),
+	/* UAC_VERSION_2, UAC2_SAMPLE_RATE_CONVERTER: not implemented yet */
+
+	/* UAC3 */
+	FIXED(UAC_VERSION_2, UAC_HEADER, struct uac3_ac_header_descriptor),
+	FIXED(UAC_VERSION_3, UAC_INPUT_TERMINAL,
+	      struct uac3_input_terminal_descriptor),
+	FIXED(UAC_VERSION_3, UAC_OUTPUT_TERMINAL,
+	      struct uac3_output_terminal_descriptor),
+	/* UAC_VERSION_3, UAC3_EXTENDED_TERMINAL: not implemented yet */
+	FUNC(UAC_VERSION_3, UAC3_MIXER_UNIT, validate_mixer_unit),
+	FUNC(UAC_VERSION_3, UAC3_SELECTOR_UNIT, validate_selector_unit),
+	FUNC(UAC_VERSION_3, UAC_FEATURE_UNIT, validate_uac3_feature_unit),
+	/*  UAC_VERSION_3, UAC3_EFFECT_UNIT: not implemented yet */
+	FUNC(UAC_VERSION_3, UAC3_PROCESSING_UNIT, validate_processing_unit),
+	FUNC(UAC_VERSION_3, UAC3_EXTENSION_UNIT, validate_processing_unit),
+	FIXED(UAC_VERSION_3, UAC3_CLOCK_SOURCE,
+	      struct uac3_clock_source_descriptor),
+	FUNC(UAC_VERSION_3, UAC3_CLOCK_SELECTOR, validate_selector_unit),
+	FIXED(UAC_VERSION_3, UAC3_CLOCK_MULTIPLIER,
+	      struct uac3_clock_multiplier_descriptor),
+	/* UAC_VERSION_3, UAC3_SAMPLE_RATE_CONVERTER: not implemented yet */
+	/* UAC_VERSION_3, UAC3_CONNECTORS: not implemented yet */
+	{ } /* terminator */
+};
+
+static struct usb_desc_validator midi_validators[] = {
+	FIXED(UAC_VERSION_ALL, USB_MS_HEADER,
+	      struct usb_ms_header_descriptor),
+	FIXED(UAC_VERSION_ALL, USB_MS_MIDI_IN_JACK,
+	      struct usb_midi_in_jack_descriptor),
+	FUNC(UAC_VERSION_ALL, USB_MS_MIDI_OUT_JACK,
+	     validate_midi_out_jack),
+	{ } /* terminator */
+};
+
+
+/* Validate the given unit descriptor, return true if it's OK */
+static bool validate_desc(unsigned char *hdr, int protocol,
+			  const struct usb_desc_validator *v)
+{
+	if (hdr[1] != USB_DT_CS_INTERFACE)
+		return true; /* don't care */
+
+	for (; v->type; v++) {
+		if (v->type == hdr[2] &&
+		    (v->protocol == UAC_VERSION_ALL ||
+		     v->protocol == protocol)) {
+			if (v->func)
+				return v->func(hdr, v);
+			/* check for the fixed size */
+			return hdr[0] >= v->size;
+		}
+	}
+
+	return true; /* not matching, skip validation */
+}
+
+bool snd_usb_validate_audio_desc(void *p, int protocol)
+{
+	return validate_desc(p, protocol, audio_validators);
+}
+
+bool snd_usb_validate_midi_desc(void *p)
+{
+	return validate_desc(p, UAC_VERSION_1, midi_validators);
+}
+