diff --git a/sound/usb/Makefile b/sound/usb/Makefile
index e1ce257ab705..d27a21b0ff9c 100644
--- a/sound/usb/Makefile
+++ b/sound/usb/Makefile
@@ -16,7 +16,8 @@ snd-usb-audio-objs := card.o \
power.o \
proc.o \
quirks.o \
- stream.o
+ stream.o \
+ validate.o
snd-usb-audio-$(CONFIG_SND_USB_AUDIO_USE_MEDIA_CONTROLLER) += media.o
diff --git a/sound/usb/helper.h b/sound/usb/helper.h
index 6afb70156ec4..5e8a18b4e7b9 100644
--- a/sound/usb/helper.h
+++ b/sound/usb/helper.h
@@ -31,4 +31,8 @@ static inline int snd_usb_ctrl_intf(struct snd_usb_audio *chip)
return get_iface_desc(chip->ctrl_intf)->bInterfaceNumber;
}
+/* in validate.c */
+bool snd_usb_validate_audio_desc(void *p, int protocol);
+bool snd_usb_validate_midi_desc(void *p);
+
#endif /* __USBAUDIO_HELPER_H */
diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index eceab19766db..a1093fb9bf09 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -785,6 +785,8 @@ static int __check_input_term(struct mixer_build *state, int id,
p1 = find_audio_control_unit(state, id);
if (!p1)
break;
+ if (!snd_usb_validate_audio_desc(p1, protocol))
+ break; /* bad descriptor */
hdr = p1;
term->id = id;
@@ -2775,6 +2777,11 @@ static int parse_audio_unit(struct mixer_build *state, int unitid)
return -EINVAL;
}
+ if (!snd_usb_validate_audio_desc(p1, protocol)) {
+ usb_audio_dbg(state->chip, "invalid unit %d\n", unitid);
+ return 0; /* skip invalid unit */
+ }
+
if (protocol == UAC_VERSION_1 || protocol == UAC_VERSION_2) {
switch (p1[2]) {
case UAC_INPUT_TERMINAL:
@@ -3145,6 +3152,9 @@ static int snd_usb_mixer_controls(struct usb_mixer_interface *mixer)
while ((p = snd_usb_find_csint_desc(mixer->hostif->extra,
mixer->hostif->extralen,
p, UAC_OUTPUT_TERMINAL)) != NULL) {
+ if (!snd_usb_validate_audio_desc(p, mixer->protocol))
+ continue; /* skip invalid descriptor */
+
if (mixer->protocol == UAC_VERSION_1) {
struct uac1_output_terminal_descriptor *desc = p;
diff --git a/sound/usb/power.c b/sound/usb/power.c
index bd303a1ba1b7..606a2cb23eab 100644
--- a/sound/usb/power.c
+++ b/sound/usb/power.c
@@ -31,6 +31,8 @@ snd_usb_find_power_domain(struct usb_host_interface *ctrl_iface,
struct uac3_power_domain_descriptor *pd_desc = p;
int i;
+ if (!snd_usb_validate_audio_desc(p, UAC_VERSION_3))
+ continue;
for (i = 0; i < pd_desc->bNrEntities; i++) {
if (pd_desc->baEntityID[i] == id) {
pd->pd_id = pd_desc->bPowerDomainID;
diff --git a/sound/usb/quirks.c b/sound/usb/quirks.c
index 78858918cbc1..7e9735aa7ac9 100644
--- a/sound/usb/quirks.c
+++ b/sound/usb/quirks.c
@@ -248,6 +248,9 @@ static int create_yamaha_midi_quirk(struct snd_usb_audio *chip,
NULL, USB_MS_MIDI_OUT_JACK);
if (!injd && !outjd)
return -ENODEV;
+ if (!snd_usb_validate_midi_desc(injd) ||
+ !snd_usb_validate_midi_desc(outjd))
+ return -ENODEV;
if (injd && (injd->bLength < 5 ||
(injd->bJackType != USB_MS_EMBEDDED &&
injd->bJackType != USB_MS_EXTERNAL)))
diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index e852c7fd6109..a0649c8ae460 100644
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -627,16 +627,14 @@ static int parse_uac_endpoint_attributes(struct snd_usb_audio *chip,
*/
static void *
snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
- int terminal_id, bool uac23)
+ int terminal_id, int protocol)
{
struct uac2_input_terminal_descriptor *term = NULL;
- size_t minlen = uac23 ? sizeof(struct uac2_input_terminal_descriptor) :
- sizeof(struct uac_input_terminal_descriptor);
while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
ctrl_iface->extralen,
term, UAC_INPUT_TERMINAL))) {
- if (term->bLength < minlen)
+ if (!snd_usb_validate_audio_desc(term, protocol))
continue;
if (term->bTerminalID == terminal_id)
return term;
@@ -647,7 +645,7 @@ snd_usb_find_input_terminal_descriptor(struct usb_host_interface *ctrl_iface,
static void *
snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
- int terminal_id)
+ int terminal_id, int protocol)
{
/* OK to use with both UAC2 and UAC3 */
struct uac2_output_terminal_descriptor *term = NULL;
@@ -655,8 +653,9 @@ snd_usb_find_output_terminal_descriptor(struct usb_host_interface *ctrl_iface,
while ((term = snd_usb_find_csint_desc(ctrl_iface->extra,
ctrl_iface->extralen,
term, UAC_OUTPUT_TERMINAL))) {
- if (term->bLength >= sizeof(*term) &&
- term->bTerminalID == terminal_id)
+ if (!snd_usb_validate_audio_desc(term, protocol))
+ continue;
+ if (term->bTerminalID == terminal_id)
return term;
}
@@ -731,7 +730,7 @@ snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
iterm = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
as->bTerminalLink,
- false);
+ protocol);
if (iterm) {
num_channels = iterm->bNrChannels;
chconfig = le16_to_cpu(iterm->wChannelConfig);
@@ -767,7 +766,7 @@ snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
*/
input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
as->bTerminalLink,
- true);
+ protocol);
if (input_term) {
clock = input_term->bCSourceID;
if (!chconfig && (num_channels == input_term->bNrChannels))
@@ -776,7 +775,8 @@ snd_usb_get_audioformat_uac12(struct snd_usb_audio *chip,
}
output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
- as->bTerminalLink);
+ as->bTerminalLink,
+ protocol);
if (output_term) {
clock = output_term->bCSourceID;
goto found_clock;
@@ -1002,14 +1002,15 @@ snd_usb_get_audioformat_uac3(struct snd_usb_audio *chip,
*/
input_term = snd_usb_find_input_terminal_descriptor(chip->ctrl_intf,
as->bTerminalLink,
- true);
+ UAC_VERSION_3);
if (input_term) {
clock = input_term->bCSourceID;
goto found_clock;
}
output_term = snd_usb_find_output_terminal_descriptor(chip->ctrl_intf,
- as->bTerminalLink);
+ as->bTerminalLink,
+ UAC_VERSION_3);
if (output_term) {
clock = output_term->bCSourceID;
goto found_clock;
diff --git a/sound/usb/validate.c b/sound/usb/validate.c
new file mode 100644
index 000000000000..3c8f73a0eb12
--- /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 = d->bLength < sizeof(*d) + d->bNrInPins;
+ if (d->bLength < len)
+ return false;
+ switch (v->protocol) {
+ case UAC_VERSION_1:
+ default:
+ /* bNrChannels, wChannelConfig, iChannelNames, bControlSize */
+ len += 1 + 2 + 1 + 1;
+ if (d->bLength < len) /* 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);
+}
+