1 // SPDX-License-Identifier: GPL-2.0-or-later
2 //
3 // Validation of USB-audio class descriptors
4 //
5
6 #include <linux/init.h>
7 #include <linux/usb.h>
8 #include <linux/usb/audio.h>
9 #include <linux/usb/audio-v2.h>
10 #include <linux/usb/audio-v3.h>
11 #include <linux/usb/midi.h>
12 #include "usbaudio.h"
13 #include "helper.h"
14
15 struct usb_desc_validator {
16 unsigned char protocol;
17 unsigned char type;
18 bool (*func)(const void *p, const struct usb_desc_validator *v);
19 size_t size;
20 };
21
22 #define UAC_VERSION_ALL (unsigned char)(-1)
23
24 /* UAC1 only */
25 static bool validate_uac1_header(const void *p,
26 const struct usb_desc_validator *v)
27 {
28 const struct uac1_ac_header_descriptor *d = p;
29
30 return d->bLength >= sizeof(*d) &&
31 d->bLength >= sizeof(*d) + d->bInCollection;
32 }
33
34 /* for mixer unit; covering all UACs */
35 static bool validate_mixer_unit(const void *p,
36 const struct usb_desc_validator *v)
37 {
38 const struct uac_mixer_unit_descriptor *d = p;
39 size_t len;
40
41 if (d->bLength < sizeof(*d) || !d->bNrInPins)
42 return false;
43 len = sizeof(*d) + d->bNrInPins;
44 /* We can't determine the bitmap size only from this unit descriptor,
45 * so just check with the remaining length.
46 * The actual bitmap is checked at mixer unit parser.
47 */
48 switch (v->protocol) {
49 case UAC_VERSION_1:
50 default:
51 len += 2 + 1; /* wChannelConfig, iChannelNames */
52 /* bmControls[n*m] */
53 len += 1; /* iMixer */
54 break;
55 case UAC_VERSION_2:
56 len += 4 + 1; /* bmChannelConfig, iChannelNames */
57 /* bmMixerControls[n*m] */
58 len += 1 + 1; /* bmControls, iMixer */
59 break;
60 case UAC_VERSION_3:
61 len += 2; /* wClusterDescrID */
62 /* bmMixerControls[n*m] */
63 break;
64 }
65 return d->bLength >= len;
66 }
67
68 /* both for processing and extension units; covering all UACs */
69 static bool validate_processing_unit(const void *p,
70 const struct usb_desc_validator *v)
71 {
72 const struct uac_processing_unit_descriptor *d = p;
73 const unsigned char *hdr = p;
74 size_t len, m;
75
76 if (d->bLength < sizeof(*d))
77 return false;
78 len = sizeof(*d) + d->bNrInPins;
79 if (d->bLength < len)
80 return false;
81 switch (v->protocol) {
82 case UAC_VERSION_1:
83 default:
84 /* bNrChannels, wChannelConfig, iChannelNames */
85 len += 1 + 2 + 1;
86 if (d->bLength < len + 1) /* bControlSize */
87 return false;
88 m = hdr[len];
89 len += 1 + m + 1; /* bControlSize, bmControls, iProcessing */
90 break;
91 case UAC_VERSION_2:
92 /* bNrChannels, bmChannelConfig, iChannelNames */
93 len += 1 + 4 + 1;
94 if (v->type == UAC2_PROCESSING_UNIT_V2)
95 len += 2; /* bmControls -- 2 bytes for PU */
96 else
97 len += 1; /* bmControls -- 1 byte for EU */
98 len += 1; /* iProcessing */
99 break;
100 case UAC_VERSION_3:
101 /* wProcessingDescrStr, bmControls */
102 len += 2 + 4;
103 break;
104 }
105 if (d->bLength < len)
106 return false;
107
108 switch (v->protocol) {
109 case UAC_VERSION_1:
110 default:
111 if (v->type == UAC1_EXTENSION_UNIT)
112 return true; /* OK */
113 switch (le16_to_cpu(d->wProcessType)) {
114 case UAC_PROCESS_UP_DOWNMIX:
115 case UAC_PROCESS_DOLBY_PROLOGIC:
116 if (d->bLength < len + 1) /* bNrModes */
117 return false;
118 m = hdr[len];
119 len += 1 + m * 2; /* bNrModes, waModes(n) */
120 break;
121 default:
122 break;
123 }
124 break;
125 case UAC_VERSION_2:
126 if (v->type == UAC2_EXTENSION_UNIT_V2)
127 return true; /* OK */
128 switch (le16_to_cpu(d->wProcessType)) {
129 case UAC2_PROCESS_UP_DOWNMIX:
130 case UAC2_PROCESS_DOLBY_PROLOCIC: /* SiC! */
131 if (d->bLength < len + 1) /* bNrModes */
132 return false;
133 m = hdr[len];
134 len += 1 + m * 4; /* bNrModes, daModes(n) */
135 break;
136 default:
137 break;
138 }
139 break;
140 case UAC_VERSION_3:
141 if (v->type == UAC3_EXTENSION_UNIT) {
142 len += 2; /* wClusterDescrID */
143 break;
144 }
145 switch (le16_to_cpu(d->wProcessType)) {
146 case UAC3_PROCESS_UP_DOWNMIX:
147 if (d->bLength < len + 1) /* bNrModes */
148 return false;
149 m = hdr[len];
150 len += 1 + m * 2; /* bNrModes, waClusterDescrID(n) */
151 break;
152 case UAC3_PROCESS_MULTI_FUNCTION:
153 len += 2 + 4; /* wClusterDescrID, bmAlgorighms */
154 break;
155 default:
156 break;
157 }
158 break;
159 }
160 if (d->bLength < len)
161 return false;
162
163 return true;
164 }
165
166 /* both for selector and clock selector units; covering all UACs */
167 static bool validate_selector_unit(const void *p,
168 const struct usb_desc_validator *v)
169 {
170 const struct uac_selector_unit_descriptor *d = p;
171 size_t len;
172
173 if (d->bLength < sizeof(*d))
174 return false;
175 len = sizeof(*d) + d->bNrInPins;
176 switch (v->protocol) {
177 case UAC_VERSION_1:
178 default:
179 len += 1; /* iSelector */
180 break;
181 case UAC_VERSION_2:
182 len += 1 + 1; /* bmControls, iSelector */
183 break;
184 case UAC_VERSION_3:
185 len += 4 + 2; /* bmControls, wSelectorDescrStr */
186 break;
187 }
188 return d->bLength >= len;
189 }
190
191 static bool validate_uac1_feature_unit(const void *p,
192 const struct usb_desc_validator *v)
193 {
194 const struct uac_feature_unit_descriptor *d = p;
195
196 if (d->bLength < sizeof(*d) || !d->bControlSize)
197 return false;
198 /* at least bmaControls(0) for master channel + iFeature */
199 return d->bLength >= sizeof(*d) + d->bControlSize + 1;
200 }
201
202 static bool validate_uac2_feature_unit(const void *p,
203 const struct usb_desc_validator *v)
204 {
205 const struct uac2_feature_unit_descriptor *d = p;
206
207 if (d->bLength < sizeof(*d))
208 return false;
209 /* at least bmaControls(0) for master channel + iFeature */
210 return d->bLength >= sizeof(*d) + 4 + 1;
211 }
212
213 static bool validate_uac3_feature_unit(const void *p,
214 const struct usb_desc_validator *v)
215 {
216 const struct uac3_feature_unit_descriptor *d = p;
217
218 if (d->bLength < sizeof(*d))
219 return false;
220 /* at least bmaControls(0) for master channel + wFeatureDescrStr */
221 return d->bLength >= sizeof(*d) + 4 + 2;
222 }
223
224 static bool validate_midi_out_jack(const void *p,
225 const struct usb_desc_validator *v)
226 {
227 const struct usb_midi_out_jack_descriptor *d = p;
228
229 return d->bLength >= sizeof(*d) &&
230 d->bLength >= sizeof(*d) + d->bNrInputPins * 2;
231 }
232
233 #define FIXED(p, t, s) { .protocol = (p), .type = (t), .size = sizeof(s) }
234 #define FUNC(p, t, f) { .protocol = (p), .type = (t), .func = (f) }
235
236 static const struct usb_desc_validator audio_validators[] = {
237 /* UAC1 */
238 FUNC(UAC_VERSION_1, UAC_HEADER, validate_uac1_header),
239 FIXED(UAC_VERSION_1, UAC_INPUT_TERMINAL,
240 struct uac_input_terminal_descriptor),
241 FIXED(UAC_VERSION_1, UAC_OUTPUT_TERMINAL,
242 struct uac1_output_terminal_descriptor),
243 FUNC(UAC_VERSION_1, UAC_MIXER_UNIT, validate_mixer_unit),
244 FUNC(UAC_VERSION_1, UAC_SELECTOR_UNIT, validate_selector_unit),
245 FUNC(UAC_VERSION_1, UAC_FEATURE_UNIT, validate_uac1_feature_unit),
246 FUNC(UAC_VERSION_1, UAC1_PROCESSING_UNIT, validate_processing_unit),
247 FUNC(UAC_VERSION_1, UAC1_EXTENSION_UNIT, validate_processing_unit),
248
249 /* UAC2 */
250 FIXED(UAC_VERSION_2, UAC_HEADER, struct uac2_ac_header_descriptor),
251 FIXED(UAC_VERSION_2, UAC_INPUT_TERMINAL,
252 struct uac2_input_terminal_descriptor),
253 FIXED(UAC_VERSION_2, UAC_OUTPUT_TERMINAL,
254 struct uac2_output_terminal_descriptor),
255 FUNC(UAC_VERSION_2, UAC_MIXER_UNIT, validate_mixer_unit),
256 FUNC(UAC_VERSION_2, UAC_SELECTOR_UNIT, validate_selector_unit),
257 FUNC(UAC_VERSION_2, UAC_FEATURE_UNIT, validate_uac2_feature_unit),
258 /* UAC_VERSION_2, UAC2_EFFECT_UNIT: not implemented yet */
259 FUNC(UAC_VERSION_2, UAC2_PROCESSING_UNIT_V2, validate_processing_unit),
260 FUNC(UAC_VERSION_2, UAC2_EXTENSION_UNIT_V2, validate_processing_unit),
261 FIXED(UAC_VERSION_2, UAC2_CLOCK_SOURCE,
262 struct uac_clock_source_descriptor),
263 FUNC(UAC_VERSION_2, UAC2_CLOCK_SELECTOR, validate_selector_unit),
264 FIXED(UAC_VERSION_2, UAC2_CLOCK_MULTIPLIER,
265 struct uac_clock_multiplier_descriptor),
266 /* UAC_VERSION_2, UAC2_SAMPLE_RATE_CONVERTER: not implemented yet */
267
268 /* UAC3 */
269 FIXED(UAC_VERSION_2, UAC_HEADER, struct uac3_ac_header_descriptor),
270 FIXED(UAC_VERSION_3, UAC_INPUT_TERMINAL,
271 struct uac3_input_terminal_descriptor),
272 FIXED(UAC_VERSION_3, UAC_OUTPUT_TERMINAL,
273 struct uac3_output_terminal_descriptor),
274 /* UAC_VERSION_3, UAC3_EXTENDED_TERMINAL: not implemented yet */
275 FUNC(UAC_VERSION_3, UAC3_MIXER_UNIT, validate_mixer_unit),
276 FUNC(UAC_VERSION_3, UAC3_SELECTOR_UNIT, validate_selector_unit),
277 FUNC(UAC_VERSION_3, UAC_FEATURE_UNIT, validate_uac3_feature_unit),
278 /* UAC_VERSION_3, UAC3_EFFECT_UNIT: not implemented yet */
279 FUNC(UAC_VERSION_3, UAC3_PROCESSING_UNIT, validate_processing_unit),
280 FUNC(UAC_VERSION_3, UAC3_EXTENSION_UNIT, validate_processing_unit),
281 FIXED(UAC_VERSION_3, UAC3_CLOCK_SOURCE,
282 struct uac3_clock_source_descriptor),
283 FUNC(UAC_VERSION_3, UAC3_CLOCK_SELECTOR, validate_selector_unit),
284 FIXED(UAC_VERSION_3, UAC3_CLOCK_MULTIPLIER,
285 struct uac3_clock_multiplier_descriptor),
286 /* UAC_VERSION_3, UAC3_SAMPLE_RATE_CONVERTER: not implemented yet */
287 /* UAC_VERSION_3, UAC3_CONNECTORS: not implemented yet */
288 { } /* terminator */
289 };
290
291 static const struct usb_desc_validator midi_validators[] = {
292 FIXED(UAC_VERSION_ALL, USB_MS_HEADER,
293 struct usb_ms_header_descriptor),
294 FIXED(UAC_VERSION_ALL, USB_MS_MIDI_IN_JACK,
295 struct usb_midi_in_jack_descriptor),
296 FUNC(UAC_VERSION_ALL, USB_MS_MIDI_OUT_JACK,
297 validate_midi_out_jack),
298 { } /* terminator */
299 };
300
301
302 /* Validate the given unit descriptor, return true if it's OK */
303 static bool validate_desc(unsigned char *hdr, int protocol,
304 const struct usb_desc_validator *v)
305 {
306 if (hdr[1] != USB_DT_CS_INTERFACE)
307 return true; /* don't care */
308
309 for (; v->type; v++) {
310 if (v->type == hdr[2] &&
311 (v->protocol == UAC_VERSION_ALL ||
312 v->protocol == protocol)) {
313 if (v->func)
314 return v->func(hdr, v);
315 /* check for the fixed size */
316 return hdr[0] >= v->size;
317 }
318 }
319
320 return true; /* not matching, skip validation */
321 }
322
323 bool snd_usb_validate_audio_desc(void *p, int protocol)
324 {
325 unsigned char *c = p;
326 bool valid;
327
328 valid = validate_desc(p, protocol, audio_validators);
329 if (!valid && snd_usb_skip_validation) {
330 print_hex_dump(KERN_ERR, "USB-audio: buggy audio desc: ",
331 DUMP_PREFIX_NONE, 16, 1, c, c[0], true);
332 valid = true;
333 }
334 return valid;
335 }
336
337 bool snd_usb_validate_midi_desc(void *p)
338 {
339 unsigned char *c = p;
340 bool valid;
341
342 valid = validate_desc(p, UAC_VERSION_1, midi_validators);
343 if (!valid && snd_usb_skip_validation) {
344 print_hex_dump(KERN_ERR, "USB-audio: buggy midi desc: ",
345 DUMP_PREFIX_NONE, 16, 1, c, c[0], true);
346 valid = true;
347 }
348 return valid;
349 }
350
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