forked from googleprojectzero/winafl
-
Notifications
You must be signed in to change notification settings - Fork 16
/
Copy pathwinafl.c
1014 lines (846 loc) · 32.1 KB
/
winafl.c
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
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/*
WinAFL - DynamoRIO client (instrumentation) code
------------------------------------------------
Written and maintained by Ivan Fratric <ifratric@google.com>
Copyright 2016 Google Inc. All Rights Reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
#define _CRT_SECURE_NO_WARNINGS
#define MAP_SIZE 65536
#include "dr_api.h"
#include "drmgr.h"
#include "drx.h"
#include "drreg.h"
#include "drwrap.h"
#ifdef USE_DRSYMS
#include "drsyms.h"
#endif
#include "modules.h"
#include "utils.h"
#include "hashtable.h"
#include "drtable.h"
#include "limits.h"
#include <string.h>
#include <stdlib.h>
#include <windows.h>
#define UNKNOWN_MODULE_ID USHRT_MAX
#ifndef PF_FASTFAIL_AVAILABLE
#define PF_FASTFAIL_AVAILABLE 23
#endif
#ifndef STATUS_FATAL_APP_EXIT
#define STATUS_FATAL_APP_EXIT ((DWORD)0x40000015L)
#endif
#ifndef STATUS_HEAP_CORRUPTION
#define STATUS_HEAP_CORRUPTION 0xC0000374
#endif
static uint verbose;
#define NOTIFY(level, fmt, ...) do { \
if (verbose >= (level)) \
dr_fprintf(STDERR, fmt, __VA_ARGS__); \
} while (0)
#define OPTION_MAX_LENGTH MAXIMUM_PATH
#define COVERAGE_BB 0
#define COVERAGE_EDGE 1
//fuzz modes
enum persistence_mode_t { native_mode = 0, in_app = 1,};
typedef struct _target_module_t {
char module_name[MAXIMUM_PATH];
struct _target_module_t *next;
} target_module_t;
typedef struct _winafl_option_t {
/* Use nudge to notify the process for termination so that
* event_exit will be called.
*/
bool nudge_kills;
bool debug_mode;
int persistence_mode;
int coverage_kind;
char logdir[MAXIMUM_PATH];
target_module_t *target_modules;
char fuzz_module[MAXIMUM_PATH];
char fuzz_method[MAXIMUM_PATH];
char pipe_name[MAXIMUM_PATH];
char shm_name[MAXIMUM_PATH];
unsigned long fuzz_offset;
int fuzz_iterations;
void **func_args;
int num_fuz_args;
drwrap_callconv_t callconv;
bool thread_coverage;
bool no_loop;
bool dr_persist_cache;
} winafl_option_t;
static winafl_option_t options;
#define NUM_THREAD_MODULE_CACHE 4
typedef struct _winafl_data_t {
module_entry_t *cache[NUM_THREAD_MODULE_CACHE];
file_t log;
unsigned char *fake_afl_area; //used for thread_coverage
unsigned char *afl_area;
} winafl_data_t;
static winafl_data_t winafl_data;
static int winafl_tls_field;
typedef struct _fuzz_target_t {
reg_t xsp; /* stack level at entry to the fuzz target */
app_pc func_pc;
int iteration;
} fuzz_target_t;
static fuzz_target_t fuzz_target;
typedef struct _debug_data_t {
int pre_hanlder_called;
int post_handler_called;
} debug_data_t;
static debug_data_t debug_data;
static module_table_t *module_table;
static client_id_t client_id;
static volatile bool go_native;
static void
event_exit(void);
static void
event_thread_exit(void *drcontext);
static HANDLE pipe;
/****************************************************************************
* Nudges
*/
enum {
NUDGE_TERMINATE_PROCESS = 1,
};
static void
event_nudge(void *drcontext, uint64 argument)
{
int nudge_arg = (int)argument;
int exit_arg = (int)(argument >> 32);
if (nudge_arg == NUDGE_TERMINATE_PROCESS) {
static int nudge_term_count;
/* handle multiple from both NtTerminateProcess and NtTerminateJobObject */
uint count = dr_atomic_add32_return_sum(&nudge_term_count, 1);
if (count == 1) {
dr_exit_process(exit_arg);
}
}
ASSERT(nudge_arg == NUDGE_TERMINATE_PROCESS, "unsupported nudge");
ASSERT(false, "should not reach"); /* should not reach */
}
static bool
event_soft_kill(process_id_t pid, int exit_code)
{
/* we pass [exit_code, NUDGE_TERMINATE_PROCESS] to target process */
dr_config_status_t res;
res = dr_nudge_client_ex(pid, client_id,
NUDGE_TERMINATE_PROCESS | (uint64)exit_code << 32,
0);
if (res == DR_SUCCESS) {
/* skip syscall since target will terminate itself */
return true;
}
/* else failed b/c target not under DR control or maybe some other
* error: let syscall go through
*/
return false;
}
/****************************************************************************
* Event Callbacks
*/
char ReadCommandFromPipe()
{
DWORD num_read;
char result;
ReadFile(pipe, &result, 1, &num_read, NULL);
return result;
}
void WriteCommandToPipe(char cmd)
{
DWORD num_written;
WriteFile(pipe, &cmd, 1, &num_written, NULL);
}
static void
dump_winafl_data()
{
dr_write_file(winafl_data.log, winafl_data.afl_area, MAP_SIZE);
}
static bool
onexception(void *drcontext, dr_exception_t *excpt) {
DWORD exception_code = excpt->record->ExceptionCode;
if(options.debug_mode)
dr_fprintf(winafl_data.log, "Exception caught: %x\n", exception_code);
if((exception_code == EXCEPTION_ACCESS_VIOLATION) ||
(exception_code == EXCEPTION_ILLEGAL_INSTRUCTION) ||
(exception_code == EXCEPTION_PRIV_INSTRUCTION) ||
(exception_code == EXCEPTION_INT_DIVIDE_BY_ZERO) ||
(exception_code == STATUS_HEAP_CORRUPTION) ||
(exception_code == EXCEPTION_STACK_OVERFLOW) ||
(exception_code == STATUS_STACK_BUFFER_OVERRUN) ||
(exception_code == STATUS_FATAL_APP_EXIT)) {
if(options.debug_mode) {
dr_fprintf(winafl_data.log, "crashed\n");
} else {
WriteCommandToPipe('C');
}
dr_exit_process(1);
}
return true;
}
static void event_thread_init(void *drcontext)
{
void **thread_data;
thread_data = (void **)dr_thread_alloc(drcontext, 2 * sizeof(void *));
thread_data[0] = 0;
if(options.thread_coverage) {
thread_data[1] = winafl_data.fake_afl_area;
} else {
thread_data[1] = winafl_data.afl_area;
}
drmgr_set_tls_field(drcontext, winafl_tls_field, thread_data);
}
static void event_thread_exit(void *drcontext)
{
void *data = drmgr_get_tls_field(drcontext, winafl_tls_field);
dr_thread_free(drcontext, data, 2 * sizeof(void *));
}
static dr_emit_flags_t
instrument_bb_coverage(void *drcontext, void *tag, instrlist_t *bb, instr_t *inst,
bool for_trace, bool translating, void *user_data)
{
static bool debug_information_output = false;
app_pc start_pc;
module_entry_t **mod_entry_cache;
module_entry_t *mod_entry;
const char *module_name;
uint offset;
target_module_t *target_modules;
bool should_instrument;
unsigned char *afl_map;
dr_emit_flags_t ret;
if (!drmgr_is_first_instr(drcontext, inst))
return DR_EMIT_DEFAULT;
start_pc = dr_fragment_app_pc(tag);
mod_entry_cache = winafl_data.cache;
mod_entry = module_table_lookup(mod_entry_cache,
NUM_THREAD_MODULE_CACHE,
module_table, start_pc);
if (mod_entry == NULL || mod_entry->data == NULL) return DR_EMIT_DEFAULT;
module_name = dr_module_preferred_name(mod_entry->data);
should_instrument = false;
target_modules = options.target_modules;
while(target_modules) {
if(_stricmp(module_name, target_modules->module_name) == 0) {
should_instrument = true;
if(options.debug_mode && debug_information_output == false) {
dr_fprintf(winafl_data.log, "Instrumenting %s with the 'bb' mode\n", module_name);
debug_information_output = true;
}
break;
}
target_modules = target_modules->next;
}
if(!should_instrument) return DR_EMIT_DEFAULT | DR_EMIT_PERSISTABLE;
offset = (uint)(start_pc - mod_entry->data->start);
offset &= MAP_SIZE - 1;
afl_map = winafl_data.afl_area;
drreg_reserve_aflags(drcontext, bb, inst);
if(options.thread_coverage || options.dr_persist_cache) {
reg_id_t reg;
opnd_t opnd1, opnd2;
instr_t *new_instr;
drreg_reserve_register(drcontext, bb, inst, NULL, ®);
drmgr_insert_read_tls_field(drcontext, winafl_tls_field, bb, inst, reg);
opnd1 = opnd_create_reg(reg);
opnd2 = OPND_CREATE_MEMPTR(reg, sizeof(void *));
new_instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
opnd1 = OPND_CREATE_MEM8(reg, offset);
new_instr = INSTR_CREATE_inc(drcontext, opnd1);
instrlist_meta_preinsert(bb, inst, new_instr);
drreg_unreserve_register(drcontext, bb, inst, reg);
ret = DR_EMIT_DEFAULT | DR_EMIT_PERSISTABLE;
} else {
instrlist_meta_preinsert(bb, inst,
INSTR_CREATE_inc(drcontext, OPND_CREATE_ABSMEM
(&(afl_map[offset]), OPSZ_1)));
ret = DR_EMIT_DEFAULT;
}
drreg_unreserve_aflags(drcontext, bb, inst);
return ret;
}
static dr_emit_flags_t
instrument_edge_coverage(void *drcontext, void *tag, instrlist_t *bb, instr_t *inst,
bool for_trace, bool translating, void *user_data)
{
static bool debug_information_output = false;
app_pc start_pc;
module_entry_t **mod_entry_cache;
module_entry_t *mod_entry;
reg_id_t reg, reg2, reg3;
opnd_t opnd1, opnd2;
instr_t *new_instr;
const char *module_name;
uint offset;
target_module_t *target_modules;
bool should_instrument;
dr_emit_flags_t ret;
if (!drmgr_is_first_instr(drcontext, inst))
return DR_EMIT_DEFAULT;
start_pc = dr_fragment_app_pc(tag);
mod_entry_cache = winafl_data.cache;
mod_entry = module_table_lookup(mod_entry_cache,
NUM_THREAD_MODULE_CACHE,
module_table, start_pc);
if (mod_entry == NULL || mod_entry->data == NULL) return DR_EMIT_DEFAULT;
module_name = dr_module_preferred_name(mod_entry->data);
should_instrument = false;
target_modules = options.target_modules;
while(target_modules) {
if(_stricmp(module_name, target_modules->module_name) == 0) {
should_instrument = true;
if(options.debug_mode && debug_information_output == false) {
dr_fprintf(winafl_data.log, "Instrumenting %s with the 'edge' mode\n", module_name);
debug_information_output = true;
}
break;
}
target_modules = target_modules->next;
}
if(!should_instrument) return DR_EMIT_DEFAULT | DR_EMIT_PERSISTABLE;
offset = (uint)(start_pc - mod_entry->data->start);
offset &= MAP_SIZE - 1;
drreg_reserve_aflags(drcontext, bb, inst);
drreg_reserve_register(drcontext, bb, inst, NULL, ®);
drreg_reserve_register(drcontext, bb, inst, NULL, ®2);
drreg_reserve_register(drcontext, bb, inst, NULL, ®3);
//reg2 stores AFL area, reg 3 stores previous offset
//load the pointer to previous offset in reg3
drmgr_insert_read_tls_field(drcontext, winafl_tls_field, bb, inst, reg3);
//load address of shm into reg2
if(options.thread_coverage || options.dr_persist_cache) {
opnd1 = opnd_create_reg(reg2);
opnd2 = OPND_CREATE_MEMPTR(reg3, sizeof(void *));
new_instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
ret = DR_EMIT_DEFAULT | DR_EMIT_PERSISTABLE;
} else {
opnd1 = opnd_create_reg(reg2);
opnd2 = OPND_CREATE_INTPTR((uint64)winafl_data.afl_area);
new_instr = INSTR_CREATE_mov_imm(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
ret = DR_EMIT_DEFAULT;
}
//load previous offset into register
opnd1 = opnd_create_reg(reg);
opnd2 = OPND_CREATE_MEMPTR(reg3, 0);
new_instr = INSTR_CREATE_mov_ld(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
//xor register with the new offset
opnd1 = opnd_create_reg(reg);
opnd2 = OPND_CREATE_INT32(offset);
new_instr = INSTR_CREATE_xor(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
//increase the counter at reg + reg2
opnd1 = opnd_create_base_disp(reg2, reg, 1, 0, OPSZ_1);
new_instr = INSTR_CREATE_inc(drcontext, opnd1);
instrlist_meta_preinsert(bb, inst, new_instr);
//store the new value
offset = (offset >> 1)&(MAP_SIZE - 1);
opnd1 = OPND_CREATE_MEMPTR(reg3, 0);
opnd2 = OPND_CREATE_INT32(offset);
new_instr = INSTR_CREATE_mov_st(drcontext, opnd1, opnd2);
instrlist_meta_preinsert(bb, inst, new_instr);
drreg_unreserve_register(drcontext, bb, inst, reg3);
drreg_unreserve_register(drcontext, bb, inst, reg2);
drreg_unreserve_register(drcontext, bb, inst, reg);
drreg_unreserve_aflags(drcontext, bb, inst);
return ret;
}
static void
pre_loop_start_handler(void *wrapcxt, INOUT void **user_data)
{
void *drcontext = drwrap_get_drcontext(wrapcxt);
if (!options.debug_mode) {
//let server know we finished a cycle, redundunt on first cycle.
WriteCommandToPipe('K');
if (fuzz_target.iteration == options.fuzz_iterations) {
dr_exit_process(0);
}
fuzz_target.iteration++;
//let server know we are starting a new cycle
WriteCommandToPipe('P');
//wait for server acknowledgement for cycle start
char command = ReadCommandFromPipe();
if (command != 'F') {
if (command == 'Q') {
dr_exit_process(0);
}
else {
char errorMessage[] = "unrecognized command received over pipe: ";
errorMessage[sizeof(errorMessage)-2] = command;
DR_ASSERT_MSG(false, errorMessage);
}
}
}
else {
debug_data.pre_hanlder_called++;
dr_fprintf(winafl_data.log, "In pre_loop_start_handler\n");
}
memset(winafl_data.afl_area, 0, MAP_SIZE);
if (options.coverage_kind == COVERAGE_EDGE || options.thread_coverage) {
void **thread_data = (void **)drmgr_get_tls_field(drcontext, winafl_tls_field);
thread_data[0] = 0;
thread_data[1] = winafl_data.afl_area;
}
}
static void
pre_fuzz_handler(void *wrapcxt, INOUT void **user_data)
{
char command = 0;
int i;
void *drcontext;
app_pc target_to_fuzz = drwrap_get_func(wrapcxt);
dr_mcontext_t *mc = drwrap_get_mcontext_ex(wrapcxt, DR_MC_ALL);
drcontext = drwrap_get_drcontext(wrapcxt);
fuzz_target.xsp = mc->xsp;
fuzz_target.func_pc = target_to_fuzz;
if(!options.debug_mode) {
WriteCommandToPipe('P');
command = ReadCommandFromPipe();
if(command != 'F') {
if(command == 'Q') {
dr_exit_process(0);
} else {
DR_ASSERT_MSG(false, "unrecognized command received over pipe");
}
}
} else {
debug_data.pre_hanlder_called++;
dr_fprintf(winafl_data.log, "In pre_fuzz_handler\n");
}
//save or restore arguments
if (!options.no_loop) {
if (fuzz_target.iteration == 0) {
for (i = 0; i < options.num_fuz_args; i++)
options.func_args[i] = drwrap_get_arg(wrapcxt, i);
} else {
for (i = 0; i < options.num_fuz_args; i++)
drwrap_set_arg(wrapcxt, i, options.func_args[i]);
}
}
memset(winafl_data.afl_area, 0, MAP_SIZE);
if(options.coverage_kind == COVERAGE_EDGE || options.thread_coverage) {
void **thread_data = (void **)drmgr_get_tls_field(drcontext, winafl_tls_field);
thread_data[0] = 0;
thread_data[1] = winafl_data.afl_area;
}
}
static void
post_fuzz_handler(void *wrapcxt, void *user_data)
{
dr_mcontext_t *mc;
mc = drwrap_get_mcontext(wrapcxt);
if(!options.debug_mode) {
WriteCommandToPipe('K');
} else {
debug_data.post_handler_called++;
dr_fprintf(winafl_data.log, "In post_fuzz_handler\n");
}
/* We don't need to reload context in case of network-based fuzzing. */
if (options.no_loop)
return;
fuzz_target.iteration++;
if(fuzz_target.iteration == options.fuzz_iterations) {
dr_exit_process(0);
}
mc->xsp = fuzz_target.xsp;
mc->pc = fuzz_target.func_pc;
drwrap_redirect_execution(wrapcxt);
}
static void
createfilew_interceptor(void *wrapcxt, INOUT void **user_data)
{
wchar_t *filenamew = (wchar_t *)drwrap_get_arg(wrapcxt, 0);
if(options.debug_mode)
dr_fprintf(winafl_data.log, "In OpenFileW, reading %ls\n", filenamew);
}
static void
createfilea_interceptor(void *wrapcxt, INOUT void **user_data)
{
char *filename = (char *)drwrap_get_arg(wrapcxt, 0);
if(options.debug_mode)
dr_fprintf(winafl_data.log, "In OpenFileA, reading %s\n", filename);
}
static void
verfierstopmessage_interceptor_pre(void *wrapctx, INOUT void **user_data)
{
EXCEPTION_RECORD exception_record = { 0 };
dr_exception_t dr_exception = { 0 };
dr_exception.record = &exception_record;
exception_record.ExceptionCode = STATUS_HEAP_CORRUPTION;
onexception(NULL, &dr_exception);
}
static void
recvfrom_interceptor(void *wrapcxt, INOUT void **user_data)
{
if (options.debug_mode)
dr_fprintf(winafl_data.log, "In recvfrom\n");
}
static void
recv_interceptor(void *wrapcxt, INOUT void **user_data)
{
if (options.debug_mode)
dr_fprintf(winafl_data.log, "In recv\n");
}
static void
isprocessorfeaturepresent_interceptor_pre(void *wrapcxt, INOUT void **user_data)
{
DWORD feature = (DWORD)drwrap_get_arg(wrapcxt, 0);
*user_data = (void*)feature;
}
static void
isprocessorfeaturepresent_interceptor_post(void *wrapcxt, void *user_data)
{
DWORD feature = (DWORD)user_data;
if(feature == PF_FASTFAIL_AVAILABLE) {
if(options.debug_mode) {
dr_fprintf(winafl_data.log, "About to make IsProcessorFeaturePresent(%d) returns 0\n", feature);
}
// Make the software thinks that _fastfail() is not supported.
drwrap_set_retval(wrapcxt, (void*)0);
}
}
static void
unhandledexceptionfilter_interceptor_pre(void *wrapcxt, INOUT void **user_data)
{
PEXCEPTION_POINTERS exception = (PEXCEPTION_POINTERS)drwrap_get_arg(wrapcxt, 0);
dr_exception_t dr_exception = { 0 };
// Fake an exception
dr_exception.record = exception->ExceptionRecord;
onexception(NULL, &dr_exception);
}
static void
event_module_unload(void *drcontext, const module_data_t *info)
{
module_table_unload(module_table, info);
}
static void
event_module_load(void *drcontext, const module_data_t *info, bool loaded)
{
const char *module_name = info->names.exe_name;
app_pc to_wrap = 0;
if (module_name == NULL) {
// In case exe_name is not defined, we will fall back on the preferred name.
module_name = dr_module_preferred_name(info);
}
if(options.debug_mode)
dr_fprintf(winafl_data.log, "Module loaded, %s\n", module_name);
if(options.fuzz_module[0]) {
if(strcmp(module_name, options.fuzz_module) == 0) {
if(options.fuzz_offset) {
to_wrap = info->start + options.fuzz_offset;
} else {
//first try exported symbols
to_wrap = (app_pc)dr_get_proc_address(info->handle, options.fuzz_method);
if(!to_wrap) {
//if that fails, try with the symbol access library
#ifdef USE_DRSYMS
drsym_init(0);
drsym_lookup_symbol(info->full_path, options.fuzz_method, (size_t *)(&to_wrap), 0);
drsym_exit();
#endif
DR_ASSERT_MSG(to_wrap, "Can't find specified method in fuzz_module");
to_wrap += (size_t)info->start;
}
}
if (options.persistence_mode == native_mode)
{
drwrap_wrap_ex(to_wrap, pre_fuzz_handler, post_fuzz_handler, NULL, options.callconv);
}
if (options.persistence_mode == in_app)
{
drwrap_wrap_ex(to_wrap, pre_loop_start_handler, NULL, NULL, options.callconv);
}
}
if (options.debug_mode && (strcmp(module_name, "WS2_32.dll") == 0)) {
to_wrap = (app_pc)dr_get_proc_address(info->handle, "recvfrom");
bool result = drwrap_wrap(to_wrap, recvfrom_interceptor, NULL);
to_wrap = (app_pc)dr_get_proc_address(info->handle, "recv");
result = drwrap_wrap(to_wrap, recv_interceptor, NULL);
}
if(options.debug_mode && (strcmp(module_name, "KERNEL32.dll") == 0)) {
to_wrap = (app_pc)dr_get_proc_address(info->handle, "CreateFileW");
drwrap_wrap(to_wrap, createfilew_interceptor, NULL);
to_wrap = (app_pc)dr_get_proc_address(info->handle, "CreateFileA");
drwrap_wrap(to_wrap, createfilea_interceptor, NULL);
}
if(_stricmp(module_name, "kernelbase.dll") == 0) {
// Since Win8, software can use _fastfail() to trigger an exception that cannot be caught.
// This is a problem for winafl as it also means DR won't be able to see it. Good thing is that
// usually those routines (__report_gsfailure for example) accounts for platforms that don't
// have support for fastfail. In those cases, they craft an exception record and pass it
// to UnhandledExceptionFilter.
//
// To work around this we set up two hooks:
// (1) IsProcessorFeaturePresent(PF_FASTFAIL_AVAILABLE): to lie and pretend that the
// platform doesn't support fastfail.
// (2) UnhandledExceptionFilter: to intercept the exception record and forward it
// to winafl's exception handler.
to_wrap = (app_pc)dr_get_proc_address(info->handle, "IsProcessorFeaturePresent");
drwrap_wrap(to_wrap, isprocessorfeaturepresent_interceptor_pre, isprocessorfeaturepresent_interceptor_post);
to_wrap = (app_pc)dr_get_proc_address(info->handle, "UnhandledExceptionFilter");
drwrap_wrap(to_wrap, unhandledexceptionfilter_interceptor_pre, NULL);
}
}
if (_stricmp(module_name, "verifier.dll") == 0) {
to_wrap = (app_pc)dr_get_proc_address(info->handle, "VerifierStopMessage");
drwrap_wrap(to_wrap, verfierstopmessage_interceptor_pre, NULL);
}
module_table_load(module_table, info);
}
static void
event_exit(void)
{
if(options.debug_mode) {
if(debug_data.pre_hanlder_called == 0) {
dr_fprintf(winafl_data.log, "WARNING: Target function was never called. Incorrect target_offset?\n");
} else if(debug_data.post_handler_called == 0) {
dr_fprintf(winafl_data.log, "WARNING: Post-fuzz handler was never reached. Did the target function return normally?\n");
} else {
dr_fprintf(winafl_data.log, "Everything appears to be running normally.\n");
}
dr_fprintf(winafl_data.log, "Coverage map follows:\n");
dump_winafl_data();
dr_close_file(winafl_data.log);
}
/* destroy module table */
module_table_destroy(module_table);
drx_exit();
drmgr_exit();
}
static void
event_init(void)
{
char buf[MAXIMUM_PATH];
module_table = module_table_create();
memset(winafl_data.cache, 0, sizeof(winafl_data.cache));
memset(winafl_data.afl_area, 0, MAP_SIZE);
if(options.debug_mode) {
debug_data.pre_hanlder_called = 0;
debug_data.post_handler_called = 0;
winafl_data.log =
drx_open_unique_appid_file(options.logdir, dr_get_process_id(),
"afl", "proc.log",
DR_FILE_ALLOW_LARGE,
buf, BUFFER_SIZE_ELEMENTS(buf));
if (winafl_data.log != INVALID_FILE) {
dr_log(NULL, LOG_ALL, 1, "winafl: log file is %s\n", buf);
NOTIFY(1, "<created log file %s>\n", buf);
}
}
fuzz_target.iteration = 0;
}
static void
setup_pipe() {
pipe = CreateFile(
options.pipe_name, // pipe name
GENERIC_READ | // read and write access
GENERIC_WRITE,
0, // no sharing
NULL, // default security attributes
OPEN_EXISTING, // opens existing pipe
0, // default attributes
NULL); // no template file
if (pipe == INVALID_HANDLE_VALUE) DR_ASSERT_MSG(false, "error connecting to pipe");
}
static void
setup_shmem() {
HANDLE map_file;
map_file = OpenFileMapping(
FILE_MAP_ALL_ACCESS, // read/write access
FALSE, // do not inherit the name
options.shm_name); // name of mapping object
if (map_file == NULL) DR_ASSERT_MSG(false, "error accesing shared memory");
winafl_data.afl_area = (unsigned char *) MapViewOfFile(map_file, // handle to map object
FILE_MAP_ALL_ACCESS, // read/write permission
0,
0,
MAP_SIZE);
if (winafl_data.afl_area == NULL) DR_ASSERT_MSG(false, "error accesing shared memory");
}
static void
options_init(client_id_t id, int argc, const char *argv[])
{
int i;
const char *token;
target_module_t *target_modules;
/* default values */
options.persistence_mode = native_mode;
options.nudge_kills = true;
options.debug_mode = false;
options.thread_coverage = false;
options.coverage_kind = COVERAGE_BB;
options.target_modules = NULL;
options.fuzz_module[0] = 0;
options.fuzz_method[0] = 0;
options.fuzz_offset = 0;
options.fuzz_iterations = 1000;
options.no_loop = false;
options.func_args = NULL;
options.num_fuz_args = 0;
options.callconv = DRWRAP_CALLCONV_DEFAULT;
options.dr_persist_cache = false;
dr_snprintf(options.logdir, BUFFER_SIZE_ELEMENTS(options.logdir), ".");
strcpy(options.pipe_name, "\\\\.\\pipe\\afl_pipe_default");
strcpy(options.shm_name, "afl_shm_default");
for (i = 1/*skip client*/; i < argc; i++) {
token = argv[i];
if (strcmp(token, "-no_nudge_kills") == 0)
options.nudge_kills = false;
else if (strcmp(token, "-nudge_kills") == 0)
options.nudge_kills = true;
else if (strcmp(token, "-thread_coverage") == 0)
options.thread_coverage = true;
else if (strcmp(token, "-debug") == 0)
options.debug_mode = true;
else if (strcmp(token, "-logdir") == 0) {
USAGE_CHECK((i + 1) < argc, "missing logdir path");
strncpy(options.logdir, argv[++i], BUFFER_SIZE_ELEMENTS(options.logdir));
}
else if (strcmp(token, "-fuzzer_id") == 0) {
USAGE_CHECK((i + 1) < argc, "missing fuzzer id");
strcpy(options.pipe_name, "\\\\.\\pipe\\afl_pipe_");
strcpy(options.shm_name, "afl_shm_");
strcat(options.pipe_name, argv[i+1]);
strcat(options.shm_name, argv[i+1]);
i++;
}
else if (strcmp(token, "-covtype") == 0) {
USAGE_CHECK((i + 1) < argc, "missing coverage type");
token = argv[++i];
if(strcmp(token, "bb")==0) options.coverage_kind = COVERAGE_BB;
else if (strcmp(token, "edge")==0) options.coverage_kind = COVERAGE_EDGE;
else USAGE_CHECK(false, "invalid coverage type");
}
else if (strcmp(token, "-coverage_module") == 0) {
USAGE_CHECK((i + 1) < argc, "missing module");
target_modules = options.target_modules;
options.target_modules = (target_module_t *)dr_global_alloc(sizeof(target_module_t));
options.target_modules->next = target_modules;
strncpy(options.target_modules->module_name, argv[++i], BUFFER_SIZE_ELEMENTS(options.target_modules->module_name));
}
else if (strcmp(token, "-target_module") == 0) {
USAGE_CHECK((i + 1) < argc, "missing module");
strncpy(options.fuzz_module, argv[++i], BUFFER_SIZE_ELEMENTS(options.fuzz_module));
}
else if (strcmp(token, "-target_method") == 0) {
USAGE_CHECK((i + 1) < argc, "missing method");
strncpy(options.fuzz_method, argv[++i], BUFFER_SIZE_ELEMENTS(options.fuzz_method));
}
else if (strcmp(token, "-fuzz_iterations") == 0) {
USAGE_CHECK((i + 1) < argc, "missing number of iterations");
options.fuzz_iterations = atoi(argv[++i]);
}
else if (strcmp(token, "-nargs") == 0) {
USAGE_CHECK((i + 1) < argc, "missing number of arguments");
options.num_fuz_args = atoi(argv[++i]);
}
else if (strcmp(token, "-target_offset") == 0) {
USAGE_CHECK((i + 1) < argc, "missing offset");
options.fuzz_offset = strtoul(argv[++i], NULL, 0);
}
else if (strcmp(token, "-verbose") == 0) {
USAGE_CHECK((i + 1) < argc, "missing -verbose number");
token = argv[++i];
if (dr_sscanf(token, "%u", &verbose) != 1) {
USAGE_CHECK(false, "invalid -verbose number");
}
}
else if (strcmp(token, "-call_convention") == 0) {
USAGE_CHECK((i + 1) < argc, "missing calling convention");
++i;
if (strcmp(argv[i], "stdcall") == 0)
options.callconv = DRWRAP_CALLCONV_CDECL;
else if (strcmp(argv[i], "fastcall") == 0)
options.callconv = DRWRAP_CALLCONV_FASTCALL;
else if (strcmp(argv[i], "thiscall") == 0)
options.callconv = DRWRAP_CALLCONV_THISCALL;
else if (strcmp(argv[i], "ms64") == 0)
options.callconv = DRWRAP_CALLCONV_MICROSOFT_X64;
else
NOTIFY(0, "Unknown calling convention, using default value instead.\n");
}
else if (strcmp(token, "-no_loop") == 0) {
options.no_loop = true;
}
else if (strcmp(token, "-drpersist") == 0) {
options.dr_persist_cache = true;
}
else if (strcmp(token, "-persistence_mode") == 0) {
USAGE_CHECK((i + 1) < argc, "missing mode arg: '-fuzz_mode' arg");
const char* mode = argv[++i];
if (strcmp(mode, "in_app") == 0)
{
options.persistence_mode = in_app;
}
else
{
options.persistence_mode = native_mode;
}
}
else {
NOTIFY(0, "UNRECOGNIZED OPTION: \"%s\"\n", token);
USAGE_CHECK(false, "invalid option");
}
}
if(options.fuzz_module[0] && (options.fuzz_offset == 0) && (options.fuzz_method[0] == 0)) {
USAGE_CHECK(false, "If fuzz_module is specified, then either fuzz_method or fuzz_offset must be as well");
}
if(options.num_fuz_args) {
options.func_args = (void **)dr_global_alloc(options.num_fuz_args * sizeof(void *));
}
}
DR_EXPORT void
dr_client_main(client_id_t id, int argc, const char *argv[])
{
drreg_options_t ops = {sizeof(ops), 2 /*max slots needed: aflags*/, false};
dr_set_client_name("WinAFL", "");
drmgr_init();
drx_init();
drreg_init(&ops);
drwrap_init();
options_init(id, argc, argv);
dr_register_exit_event(event_exit);
drmgr_register_exception_event(onexception);
if(options.coverage_kind == COVERAGE_BB) {
drmgr_register_bb_instrumentation_event(NULL, instrument_bb_coverage, NULL);
} else if(options.coverage_kind == COVERAGE_EDGE) {
drmgr_register_bb_instrumentation_event(NULL, instrument_edge_coverage, NULL);
}
drmgr_register_module_load_event(event_module_load);
drmgr_register_module_unload_event(event_module_unload);
dr_register_nudge_event(event_nudge, id);
client_id = id;
if (options.nudge_kills)
drx_register_soft_kills(event_soft_kill);
if(options.thread_coverage) {
winafl_data.fake_afl_area = (unsigned char *)dr_global_alloc(MAP_SIZE);
}
if(!options.debug_mode) {
setup_pipe();
setup_shmem();
} else {