1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
|
$NetBSD: patch-src_fc_fserve.c,v 1.2.2.2 2014/05/21 13:14:03 tron Exp $
--- src/fc/fserve.c.orig 2014-01-07 16:25:08.000000000 +0000
+++ src/fc/fserve.c
@@ -70,6 +70,7 @@ in this Software without prior written a
#include "fservestr.h"
#include <X11/fonts/fontutil.h>
#include <errno.h>
+#include <limits.h>
#include <time.h>
#define Time_t time_t
@@ -91,6 +92,15 @@ in this Software without prior written a
(pci)->descent || \
(pci)->characterWidth)
+/*
+ * SIZEOF(r) is in bytes, length fields in the protocol are in 32-bit words,
+ * so this converts for doing size comparisons.
+ */
+#define LENGTHOF(r) (SIZEOF(r) >> 2)
+
+/* Somewhat arbitrary limit on maximum reply size we'll try to read. */
+#define MAX_REPLY_LENGTH ((64 * 1024 * 1024) >> 2)
+
extern void ErrorF(const char *f, ...);
static int fs_read_glyphs ( FontPathElementPtr fpe, FSBlockDataPtr blockrec );
@@ -206,9 +216,22 @@ _fs_add_rep_log (FSFpePtr conn, fsGeneri
rep->sequenceNumber,
conn->reqbuffer[i].opcode);
}
+
+#define _fs_reply_failed(rep, name, op) do { \
+ if (rep) { \
+ if (rep->type == FS_Error) \
+ fprintf (stderr, "Error: %d Request: %s\n", \
+ ((fsError *)rep)->request, #name); \
+ else \
+ fprintf (stderr, "Bad Length for %s Reply: %d %s %d\n", \
+ #name, rep->length, op, LENGTHOF(name)); \
+ } \
+} while (0)
+
#else
#define _fs_add_req_log(conn,op) ((conn)->current_seq++)
#define _fs_add_rep_log(conn,rep)
+#define _fs_reply_failed(rep,name,op)
#endif
static Bool
@@ -600,6 +623,21 @@ fs_get_reply (FSFpePtr conn, int *error)
rep = (fsGenericReply *) buf;
+ /*
+ * Refuse to accept replies longer than a maximum reasonable length,
+ * before we pass to _fs_start_read, since it will try to resize the
+ * incoming connection buffer to this size. Also avoids integer overflow
+ * on 32-bit systems.
+ */
+ if (rep->length > MAX_REPLY_LENGTH)
+ {
+ ErrorF("fserve: reply length %d > MAX_REPLY_LENGTH, disconnecting"
+ " from font server\n", rep->length);
+ _fs_connection_died (conn);
+ *error = FSIO_ERROR;
+ return 0;
+ }
+
ret = _fs_start_read (conn, rep->length << 2, &buf);
if (ret != FSIO_READY)
{
@@ -682,13 +720,15 @@ fs_read_open_font(FontPathElementPtr fpe
int ret;
rep = (fsOpenBitmapFontReply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ (rep->length != LENGTHOF(fsOpenBitmapFontReply)))
{
if (ret == FSIO_BLOCK)
return StillWorking;
if (rep)
_fs_done_read (conn, rep->length << 2);
fs_cleanup_bfont (bfont);
+ _fs_reply_failed (rep, fsOpenBitmapFontReply, "!=");
return BadFontName;
}
@@ -815,6 +855,7 @@ fs_read_query_info(FontPathElementPtr fp
FSFpePtr conn = (FSFpePtr) fpe->private;
fsQueryXInfoReply *rep;
char *buf;
+ long bufleft; /* length of reply left to use */
fsPropInfo *pi;
fsPropOffset *po;
pointer pd;
@@ -824,13 +865,15 @@ fs_read_query_info(FontPathElementPtr fp
int ret;
rep = (fsQueryXInfoReply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ (rep->length < LENGTHOF(fsQueryXInfoReply)))
{
if (ret == FSIO_BLOCK)
return StillWorking;
if (rep)
_fs_done_read (conn, rep->length << 2);
fs_cleanup_bfont (bfont);
+ _fs_reply_failed (rep, fsQueryXInfoReply, "<");
return BadFontName;
}
@@ -844,6 +887,9 @@ fs_read_query_info(FontPathElementPtr fp
buf = (char *) rep;
buf += SIZEOF(fsQueryXInfoReply);
+ bufleft = rep->length << 2;
+ bufleft -= SIZEOF(fsQueryXInfoReply);
+
/* move the data over */
fsUnpack_XFontInfoHeader(rep, pInfo);
@@ -851,17 +897,50 @@ fs_read_query_info(FontPathElementPtr fp
_fs_init_fontinfo(conn, pInfo);
/* Compute offsets into the reply */
+ if (bufleft < SIZEOF(fsPropInfo))
+ {
+ ret = -1;
+#ifdef DEBUG
+ fprintf(stderr, "fsQueryXInfo: bufleft (%ld) < SIZEOF(fsPropInfo)\n",
+ bufleft);
+#endif
+ goto bail;
+ }
pi = (fsPropInfo *) buf;
buf += SIZEOF (fsPropInfo);
+ bufleft -= SIZEOF(fsPropInfo);
+ if ((bufleft / SIZEOF(fsPropOffset)) < pi->num_offsets)
+ {
+ ret = -1;
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXInfo: bufleft (%ld) / SIZEOF(fsPropOffset) < %d\n",
+ bufleft, pi->num_offsets);
+#endif
+ goto bail;
+ }
po = (fsPropOffset *) buf;
buf += pi->num_offsets * SIZEOF(fsPropOffset);
+ bufleft -= pi->num_offsets * SIZEOF(fsPropOffset);
+ if (bufleft < pi->data_len)
+ {
+ ret = -1;
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXInfo: bufleft (%ld) < data_len (%d)\n",
+ bufleft, pi->data_len);
+#endif
+ goto bail;
+ }
pd = (pointer) buf;
buf += pi->data_len;
+ bufleft -= pi->data_len;
/* convert the properties and step over the reply */
ret = _fs_convert_props(pi, po, pd, pInfo);
+ bail:
_fs_done_read (conn, rep->length << 2);
if (ret == -1)
@@ -951,13 +1030,15 @@ fs_read_extent_info(FontPathElementPtr f
FontInfoRec *fi = &bfont->pfont->info;
rep = (fsQueryXExtents16Reply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ (rep->length < LENGTHOF(fsQueryXExtents16Reply)))
{
if (ret == FSIO_BLOCK)
return StillWorking;
if (rep)
_fs_done_read (conn, rep->length << 2);
fs_cleanup_bfont (bfont);
+ _fs_reply_failed (rep, fsQueryXExtents16Reply, "<");
return BadFontName;
}
@@ -970,7 +1051,26 @@ fs_read_extent_info(FontPathElementPtr f
numInfos *= 2;
haveInk = TRUE;
}
- ci = pCI = malloc(sizeof(CharInfoRec) * numInfos);
+ if (numInfos >= (INT_MAX / sizeof(CharInfoRec))) {
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXExtents16: numInfos (%d) >= %ld\n",
+ numInfos, (INT_MAX / sizeof(CharInfoRec)));
+#endif
+ pCI = NULL;
+ }
+ else if (numExtents > ((rep->length - LENGTHOF(fsQueryXExtents16Reply))
+ / LENGTHOF(fsXCharInfo))) {
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXExtents16: numExtents (%d) > (%d - %d) / %d\n",
+ numExtents, rep->length,
+ LENGTHOF(fsQueryXExtents16Reply), LENGTHOF(fsXCharInfo));
+#endif
+ pCI = NULL;
+ }
+ else
+ pCI = malloc(sizeof(CharInfoRec) * numInfos);
if (!pCI)
{
@@ -1809,6 +1909,7 @@ fs_read_glyphs(FontPathElementPtr fpe, F
FontInfoPtr pfi = &pfont->info;
fsQueryXBitmaps16Reply *rep;
char *buf;
+ long bufleft; /* length of reply left to use */
fsOffset32 *ppbits;
fsOffset32 local_off;
char *off_adr;
@@ -1825,21 +1926,48 @@ fs_read_glyphs(FontPathElementPtr fpe, F
unsigned long minchar, maxchar;
rep = (fsQueryXBitmaps16Reply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ (rep->length < LENGTHOF(fsQueryXBitmaps16Reply)))
{
if (ret == FSIO_BLOCK)
return StillWorking;
if (rep)
_fs_done_read (conn, rep->length << 2);
err = AllocError;
+ _fs_reply_failed (rep, fsQueryXBitmaps16Reply, "<");
goto bail;
}
buf = (char *) rep;
buf += SIZEOF (fsQueryXBitmaps16Reply);
+ bufleft = rep->length << 2;
+ bufleft -= SIZEOF (fsQueryXBitmaps16Reply);
+
+ if ((bufleft / SIZEOF (fsOffset32)) < rep->num_chars)
+ {
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXBitmaps16: num_chars (%d) > bufleft (%ld) / %d\n",
+ rep->num_chars, bufleft, SIZEOF (fsOffset32));
+#endif
+ err = AllocError;
+ goto bail;
+ }
ppbits = (fsOffset32 *) buf;
buf += SIZEOF (fsOffset32) * (rep->num_chars);
+ bufleft -= SIZEOF (fsOffset32) * (rep->num_chars);
+
+ if (bufleft < rep->nbytes)
+ {
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsQueryXBitmaps16: nbytes (%d) > bufleft (%ld)\n",
+ rep->nbytes, bufleft);
+#endif
+ err = AllocError;
+ goto bail;
+ }
pbitmaps = (pointer ) buf;
@@ -1898,7 +2026,9 @@ fs_read_glyphs(FontPathElementPtr fpe, F
*/
if (NONZEROMETRICS(&fsdata->encoding[minchar].metrics))
{
- if (local_off.length)
+ if (local_off.length &&
+ (local_off.position < rep->nbytes) &&
+ (local_off.length <= (rep->nbytes - local_off.position)))
{
bits = allbits;
allbits += local_off.length;
@@ -2228,31 +2358,48 @@ fs_read_list(FontPathElementPtr fpe, FSB
FSBlockedListPtr blist = (FSBlockedListPtr) blockrec->data;
fsListFontsReply *rep;
char *data;
+ long dataleft; /* length of reply left to use */
int length,
i,
ret;
int err;
rep = (fsListFontsReply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ (rep->length < LENGTHOF(fsListFontsReply)))
{
if (ret == FSIO_BLOCK)
return StillWorking;
if (rep)
_fs_done_read (conn, rep->length << 2);
+ _fs_reply_failed (rep, fsListFontsReply, "<");
return AllocError;
}
data = (char *) rep + SIZEOF (fsListFontsReply);
+ dataleft = (rep->length << 2) - SIZEOF (fsListFontsReply);
err = Successful;
/* copy data into FontPathRecord */
for (i = 0; i < rep->nFonts; i++)
{
+ if (dataleft < 1)
+ break;
length = *(unsigned char *)data++;
+ dataleft--; /* used length byte */
+ if (length > dataleft) {
+#ifdef DEBUG
+ fprintf(stderr,
+ "fsListFonts: name length (%d) > dataleft (%ld)\n",
+ length, dataleft);
+#endif
+ err = BadFontName;
+ break;
+ }
err = AddFontNamesName(blist->names, data, length);
if (err != Successful)
break;
data += length;
+ dataleft -= length;
}
_fs_done_read (conn, rep->length << 2);
return err;
@@ -2358,12 +2505,15 @@ fs_read_list_info(FontPathElementPtr fpe
_fs_free_props (&binfo->info);
rep = (fsListFontsWithXInfoReply *) fs_get_reply (conn, &ret);
- if (!rep || rep->type == FS_Error)
+ if (!rep || rep->type == FS_Error ||
+ ((rep->nameLength != 0) &&
+ (rep->length < LENGTHOF(fsListFontsWithXInfoReply))))
{
if (ret == FSIO_BLOCK)
return StillWorking;
binfo->status = FS_LFWI_FINISHED;
err = AllocError;
+ _fs_reply_failed (rep, fsListFontsWithXInfoReply, "<");
goto done;
}
/*
@@ -2786,7 +2936,7 @@ _fs_recv_conn_setup (FSFpePtr conn)
int ret = FSIO_ERROR;
fsConnSetup *setup;
FSFpeAltPtr alts;
- int i, alt_len;
+ unsigned int i, alt_len;
int setup_len;
char *alt_save, *alt_names;
@@ -2813,8 +2963,9 @@ _fs_recv_conn_setup (FSFpePtr conn)
}
if (setup->num_alternates)
{
+ size_t alt_name_len = setup->alternate_len << 2;
alts = malloc (setup->num_alternates * sizeof (FSFpeAltRec) +
- (setup->alternate_len << 2));
+ alt_name_len);
if (alts)
{
alt_names = (char *) (setup + 1);
@@ -2823,10 +2974,25 @@ _fs_recv_conn_setup (FSFpePtr conn)
{
alts[i].subset = alt_names[0];
alt_len = alt_names[1];
+ if (alt_len >= alt_name_len) {
+ /*
+ * Length is longer than setup->alternate_len
+ * told us to allocate room for, assume entire
+ * alternate list is corrupted.
+ */
+#ifdef DEBUG
+ fprintf (stderr,
+ "invalid alt list (length %lx >= %lx)\n",
+ (long) alt_len, (long) alt_name_len);
+#endif
+ free(alts);
+ return FSIO_ERROR;
+ }
alts[i].name = alt_save;
memcpy (alt_save, alt_names + 2, alt_len);
alt_save[alt_len] = '\0';
alt_save += alt_len + 1;
+ alt_name_len -= alt_len + 1;
alt_names += _fs_pad_length (alt_len + 2);
}
conn->numAlts = setup->num_alternates;
|
