| 1 |
/* |
| 2 |
* Path sandbox for the gentoo linux portage package system, initially |
| 3 |
* based on the ROCK Linux Wrapper for getting a list of created files |
| 4 |
* |
| 5 |
* to integrate with bash, bash should have been built like this |
| 6 |
* |
| 7 |
* ./configure --prefix=<prefix> --host=<host> --without-gnu-malloc |
| 8 |
* |
| 9 |
* it's very important that the --enable-static-link option is NOT specified |
| 10 |
* |
| 11 |
* Copyright (C) 2001 Geert Bevin, Uwyn, http://www.uwyn.com |
| 12 |
* Distributed under the terms of the GNU General Public License, v2 or later |
| 13 |
* Author : Geert Bevin <gbevin@uwyn.com> |
| 14 |
* |
| 15 |
* Post Bevin leaving Gentoo ranks: |
| 16 |
* -------------------------------- |
| 17 |
* Ripped out all the wrappers, and implemented those of InstallWatch. |
| 18 |
* Losts of cleanups and bugfixes. Implement a execve that forces $LIBSANDBOX |
| 19 |
* in $LD_PRELOAD. Reformat the whole thing to look somewhat like the reworked |
| 20 |
* sandbox.c from Brad House <brad@mainstreetsoftworks.com>. |
| 21 |
* |
| 22 |
* Martin Schlemmer <azarah@gentoo.org> (18 Aug 2002) |
| 23 |
* |
| 24 |
* Partly Copyright (C) 1998-9 Pancrazio `Ezio' de Mauro <p@demauro.net>, |
| 25 |
* as some of the InstallWatch code was used. |
| 26 |
* |
| 27 |
* |
| 28 |
* $Header$ |
| 29 |
* |
| 30 |
*/ |
| 31 |
|
| 32 |
/* Uncomment below to enable wrapping of mknod(). |
| 33 |
* This is broken currently. */ |
| 34 |
/* #define WRAP_MKNOD 1 */ |
| 35 |
|
| 36 |
/* Uncomment below to enable the use of strtok_r(). */ |
| 37 |
#define REENTRANT_STRTOK 1 |
| 38 |
|
| 39 |
/* Uncomment below to enable memory debugging. */ |
| 40 |
/* #define SB_MEM_DEBUG 1 */ |
| 41 |
|
| 42 |
#define open xxx_open |
| 43 |
#define open64 xxx_open64 |
| 44 |
|
| 45 |
/* Wrapping mknod, do not have any effect, and |
| 46 |
* wrapping __xmknod causes calls to it to segfault |
| 47 |
*/ |
| 48 |
#ifdef WRAP_MKNOD |
| 49 |
# define __xmknod xxx___xmknod |
| 50 |
#endif |
| 51 |
|
| 52 |
#include <dirent.h> |
| 53 |
#include <dlfcn.h> |
| 54 |
#include <errno.h> |
| 55 |
#include <fcntl.h> |
| 56 |
#include <libgen.h> |
| 57 |
#include <stdarg.h> |
| 58 |
#include <stdio.h> |
| 59 |
#include <stdlib.h> |
| 60 |
#include <string.h> |
| 61 |
#include <sys/file.h> |
| 62 |
#include <sys/stat.h> |
| 63 |
#include <sys/types.h> |
| 64 |
#include <sys/param.h> |
| 65 |
#include <unistd.h> |
| 66 |
#include <utime.h> |
| 67 |
#include "config.h" |
| 68 |
#include "localdecls.h" |
| 69 |
#include "symbols.h" |
| 70 |
|
| 71 |
#ifdef SB_MEM_DEBUG |
| 72 |
# include <mcheck.h> |
| 73 |
#endif |
| 74 |
|
| 75 |
#ifdef WRAP_MKNOD |
| 76 |
# undef __xmknod |
| 77 |
#endif |
| 78 |
|
| 79 |
#undef open |
| 80 |
#undef open64 |
| 81 |
|
| 82 |
//#include "localdecls.h" |
| 83 |
#include "sandbox.h" |
| 84 |
|
| 85 |
/* Macros to check if a function should be executed */ |
| 86 |
#define FUNCTION_SANDBOX_SAFE(func, path) \ |
| 87 |
((0 == is_sandbox_on()) || (1 == before_syscall(func, path))) |
| 88 |
|
| 89 |
#define FUNCTION_SANDBOX_SAFE_ACCESS(func, path, flags) \ |
| 90 |
((0 == is_sandbox_on()) || (1 == before_syscall_access(func, path, flags))) |
| 91 |
|
| 92 |
#define FUNCTION_SANDBOX_SAFE_OPEN_INT(func, path, flags) \ |
| 93 |
((0 == is_sandbox_on()) || (1 == before_syscall_open_int(func, path, flags))) |
| 94 |
|
| 95 |
#define FUNCTION_SANDBOX_SAFE_OPEN_CHAR(func, path, mode) \ |
| 96 |
((0 == is_sandbox_on()) || (1 == before_syscall_open_char(func, path, mode))) |
| 97 |
|
| 98 |
/* Macro to check if a wrapper is defined, if not |
| 99 |
* then try to resolve it again. */ |
| 100 |
#define check_dlsym(name) \ |
| 101 |
{ \ |
| 102 |
int old_errno=errno; \ |
| 103 |
if (!true_ ## name) \ |
| 104 |
true_ ## name = get_dlsym(symname_ ## name, symver_ ## name); \ |
| 105 |
errno=old_errno; \ |
| 106 |
} |
| 107 |
|
| 108 |
static char sandbox_lib[SB_PATH_MAX]; |
| 109 |
//static char sandbox_pids_file[255]; |
| 110 |
static char *sandbox_pids_file; |
| 111 |
|
| 112 |
typedef struct { |
| 113 |
int show_access_violation; |
| 114 |
char **deny_prefixes; |
| 115 |
int num_deny_prefixes; |
| 116 |
char **read_prefixes; |
| 117 |
int num_read_prefixes; |
| 118 |
char **write_prefixes; |
| 119 |
int num_write_prefixes; |
| 120 |
char **predict_prefixes; |
| 121 |
int num_predict_prefixes; |
| 122 |
char **write_denied_prefixes; |
| 123 |
int num_write_denied_prefixes; |
| 124 |
} sbcontext_t; |
| 125 |
|
| 126 |
static sbcontext_t sbcontext; |
| 127 |
static char **cached_env_vars; |
| 128 |
static int sb_init = 0; |
| 129 |
static int sb_path_size_warning = 0; |
| 130 |
|
| 131 |
void __attribute__ ((constructor)) libsb_init(void); |
| 132 |
void __attribute__ ((destructor)) libsb_fini(void); |
| 133 |
|
| 134 |
/* glibc modified realpath() functions */ |
| 135 |
static char *erealpath(const char *, char *); |
| 136 |
/* glibc modified getcwd() functions */ |
| 137 |
static char *egetcwd(char *, size_t); |
| 138 |
|
| 139 |
static void init_wrappers(void); |
| 140 |
static void *get_dlsym(const char *, const char *); |
| 141 |
static int canonicalize(const char *, char *); |
| 142 |
static char *filter_path(const char *, int); |
| 143 |
static int check_access(sbcontext_t *, const char *, const char *, const char *); |
| 144 |
static int check_syscall(sbcontext_t *, const char *, const char *); |
| 145 |
static int before_syscall(const char *, const char *); |
| 146 |
static int before_syscall_access(const char *, const char *, int); |
| 147 |
static int before_syscall_open_int(const char *, const char *, int); |
| 148 |
static int before_syscall_open_char(const char *, const char *, const char *); |
| 149 |
static void clean_env_entries(char ***, int *); |
| 150 |
static void init_context(sbcontext_t *); |
| 151 |
static void init_env_entries(char ***, int *, const char *, const char *, int); |
| 152 |
static int is_sandbox_on(); |
| 153 |
static int is_sandbox_pid(); |
| 154 |
|
| 155 |
/* Wrapped functions */ |
| 156 |
|
| 157 |
extern int chmod(const char *, mode_t); |
| 158 |
static int (*true_chmod) (const char *, mode_t) = NULL; |
| 159 |
extern int chown(const char *, uid_t, gid_t); |
| 160 |
static int (*true_chown) (const char *, uid_t, gid_t) = NULL; |
| 161 |
extern int creat(const char *, mode_t); |
| 162 |
static int (*true_creat) (const char *, mode_t) = NULL; |
| 163 |
extern FILE *fopen(const char *, const char *); |
| 164 |
static FILE *(*true_fopen) (const char *, const char *) = NULL; |
| 165 |
extern int lchown(const char *, uid_t, gid_t); |
| 166 |
static int (*true_lchown) (const char *, uid_t, gid_t) = NULL; |
| 167 |
extern int link(const char *, const char *); |
| 168 |
static int (*true_link) (const char *, const char *) = NULL; |
| 169 |
extern int mkdir(const char *, mode_t); |
| 170 |
static int (*true_mkdir) (const char *, mode_t) = NULL; |
| 171 |
extern DIR *opendir(const char *); |
| 172 |
static DIR *(*true_opendir) (const char *) = NULL; |
| 173 |
#ifdef WRAP_MKNOD |
| 174 |
extern int __xmknod(const char *, mode_t, dev_t); |
| 175 |
static int (*true___xmknod) (const char *, mode_t, dev_t) = NULL; |
| 176 |
#endif |
| 177 |
extern int access(const char *, int); |
| 178 |
static int (*true_access) (const char *, int) = NULL; |
| 179 |
extern int open(const char *, int, ...); |
| 180 |
static int (*true_open) (const char *, int, ...) = NULL; |
| 181 |
extern int rename(const char *, const char *); |
| 182 |
static int (*true_rename) (const char *, const char *) = NULL; |
| 183 |
extern int rmdir(const char *); |
| 184 |
static int (*true_rmdir) (const char *) = NULL; |
| 185 |
extern int symlink(const char *, const char *); |
| 186 |
static int (*true_symlink) (const char *, const char *) = NULL; |
| 187 |
extern int truncate(const char *, TRUNCATE_T); |
| 188 |
static int (*true_truncate) (const char *, TRUNCATE_T) = NULL; |
| 189 |
extern int unlink(const char *); |
| 190 |
static int (*true_unlink) (const char *) = NULL; |
| 191 |
|
| 192 |
#if (GLIBC_MINOR >= 1) |
| 193 |
|
| 194 |
extern int creat64(const char *, __mode_t); |
| 195 |
static int (*true_creat64) (const char *, __mode_t) = NULL; |
| 196 |
extern FILE *fopen64(const char *, const char *); |
| 197 |
static FILE *(*true_fopen64) (const char *, const char *) = NULL; |
| 198 |
extern int open64(const char *, int, ...); |
| 199 |
static int (*true_open64) (const char *, int, ...) = NULL; |
| 200 |
extern int truncate64(const char *, __off64_t); |
| 201 |
static int (*true_truncate64) (const char *, __off64_t) = NULL; |
| 202 |
|
| 203 |
#endif |
| 204 |
|
| 205 |
extern int execve(const char *filename, char *const argv[], char *const envp[]); |
| 206 |
static int (*true_execve) (const char *, char *const[], char *const[]); |
| 207 |
|
| 208 |
/* |
| 209 |
* Initialize the shabang |
| 210 |
*/ |
| 211 |
|
| 212 |
static void init_wrappers(void) |
| 213 |
{ |
| 214 |
check_dlsym(chmod); |
| 215 |
check_dlsym(chown); |
| 216 |
check_dlsym(creat); |
| 217 |
check_dlsym(fopen); |
| 218 |
check_dlsym(lchown); |
| 219 |
check_dlsym(link); |
| 220 |
check_dlsym(mkdir); |
| 221 |
check_dlsym(opendir); |
| 222 |
#ifdef WRAP_MKNOD |
| 223 |
check_dlsym(__xmknod); |
| 224 |
#endif |
| 225 |
check_dlsym(access); |
| 226 |
check_dlsym(open); |
| 227 |
check_dlsym(rename); |
| 228 |
check_dlsym(rmdir); |
| 229 |
check_dlsym(symlink); |
| 230 |
check_dlsym(truncate); |
| 231 |
check_dlsym(unlink); |
| 232 |
|
| 233 |
#if (GLIBC_MINOR >= 1) |
| 234 |
check_dlsym(creat64); |
| 235 |
check_dlsym(fopen64); |
| 236 |
check_dlsym(open64); |
| 237 |
check_dlsym(truncate64); |
| 238 |
#endif |
| 239 |
|
| 240 |
check_dlsym(execve); |
| 241 |
} |
| 242 |
|
| 243 |
static void *libc_handle = NULL; |
| 244 |
|
| 245 |
static void *get_dlsym(const char *symname, const char *symver) |
| 246 |
{ |
| 247 |
void *symaddr = NULL; |
| 248 |
|
| 249 |
if (NULL == libc_handle) { |
| 250 |
#ifdef BROKEN_RTLD_NEXT |
| 251 |
libc_handle = dlopen(LIBC_VERSION, RTLD_LAZY); |
| 252 |
if (!libc_handle) { |
| 253 |
printf("libsandbox.so: Can't dlopen libc: %s\n", dlerror()); |
| 254 |
abort(); |
| 255 |
} |
| 256 |
#else |
| 257 |
libc_handle = RTLD_NEXT; |
| 258 |
#endif |
| 259 |
} |
| 260 |
|
| 261 |
if (NULL == symver) |
| 262 |
symaddr = dlsym(libc_handle, symname); |
| 263 |
else |
| 264 |
symaddr = dlvsym(libc_handle, symname, symver); |
| 265 |
if (!symaddr) { |
| 266 |
printf("libsandbox.so: Can't resolve %s: %s\n", symname, dlerror()); |
| 267 |
abort(); |
| 268 |
} |
| 269 |
|
| 270 |
return symaddr; |
| 271 |
} |
| 272 |
|
| 273 |
|
| 274 |
void __attribute__ ((destructor)) libsb_fini(void) |
| 275 |
{ |
| 276 |
int x; |
| 277 |
if(NULL != cached_env_vars) { |
| 278 |
for(x=0; x < 4; x++) { |
| 279 |
if(NULL != cached_env_vars[x]) |
| 280 |
free(cached_env_vars[x]); |
| 281 |
} |
| 282 |
free(cached_env_vars); |
| 283 |
} |
| 284 |
clean_env_entries(&(sbcontext.deny_prefixes), |
| 285 |
&(sbcontext.num_deny_prefixes)); |
| 286 |
clean_env_entries(&(sbcontext.read_prefixes), |
| 287 |
&(sbcontext.num_read_prefixes)); |
| 288 |
clean_env_entries(&(sbcontext.write_prefixes), |
| 289 |
&(sbcontext.num_write_prefixes)); |
| 290 |
clean_env_entries(&(sbcontext.predict_prefixes), |
| 291 |
&(sbcontext.num_predict_prefixes)); |
| 292 |
|
| 293 |
free(sandbox_pids_file); |
| 294 |
} |
| 295 |
|
| 296 |
void __attribute__ ((constructor)) libsb_init(void) |
| 297 |
{ |
| 298 |
int old_errno = errno; |
| 299 |
char tmp_dir[SB_PATH_MAX]; |
| 300 |
|
| 301 |
#ifdef SB_MEM_DEBUG |
| 302 |
mtrace(); |
| 303 |
#endif |
| 304 |
|
| 305 |
init_wrappers(); |
| 306 |
|
| 307 |
/* Get the path and name to this library */ |
| 308 |
snprintf(sandbox_lib, SB_PATH_MAX, "%s", get_sandbox_lib("/")); |
| 309 |
|
| 310 |
if (-1 == get_tmp_dir(tmp_dir)) |
| 311 |
snprintf(tmp_dir, SB_PATH_MAX, "%s", TMPDIR); |
| 312 |
|
| 313 |
/* Generate sandbox pids-file path */ |
| 314 |
sandbox_pids_file = get_sandbox_pids_file(tmp_dir); |
| 315 |
|
| 316 |
// sb_init = 1; |
| 317 |
|
| 318 |
errno = old_errno; |
| 319 |
} |
| 320 |
|
| 321 |
static int canonicalize(const char *path, char *resolved_path) |
| 322 |
{ |
| 323 |
int old_errno = errno; |
| 324 |
char *retval; |
| 325 |
|
| 326 |
*resolved_path = '\0'; |
| 327 |
|
| 328 |
/* If path == NULL, return or we get a segfault */ |
| 329 |
if (NULL == path) { |
| 330 |
errno = EINVAL; |
| 331 |
return -1; |
| 332 |
} |
| 333 |
|
| 334 |
/* Do not try to resolve an empty path */ |
| 335 |
if ('\0' == path[0]) { |
| 336 |
errno = old_errno; |
| 337 |
return 0; |
| 338 |
} |
| 339 |
|
| 340 |
retval = erealpath(path, resolved_path); |
| 341 |
|
| 342 |
if ((NULL == retval) && (path[0] != '/')) { |
| 343 |
/* The path could not be canonicalized, append it |
| 344 |
* to the current working directory if it was not |
| 345 |
* an absolute path |
| 346 |
*/ |
| 347 |
|
| 348 |
if (ENAMETOOLONG == errno) |
| 349 |
return -1; |
| 350 |
|
| 351 |
if (NULL == egetcwd(resolved_path, SB_PATH_MAX - 2)) |
| 352 |
return -1; |
| 353 |
snprintf((char *)(resolved_path + strlen(resolved_path)), |
| 354 |
SB_PATH_MAX - strlen(resolved_path), "/%s", path); |
| 355 |
|
| 356 |
if (NULL == erealpath(resolved_path, resolved_path)) { |
| 357 |
if (errno == ENAMETOOLONG) { |
| 358 |
/* The resolved path is too long for the buffer to hold */ |
| 359 |
return -1; |
| 360 |
} else { |
| 361 |
/* Whatever it resolved, is not a valid path */ |
| 362 |
errno = ENOENT; |
| 363 |
return -1; |
| 364 |
} |
| 365 |
} |
| 366 |
|
| 367 |
} else if ((NULL == retval) && (path[0] == '/')) { |
| 368 |
/* Whatever it resolved, is not a valid path */ |
| 369 |
errno = ENOENT; |
| 370 |
return -1; |
| 371 |
} |
| 372 |
|
| 373 |
errno = old_errno; |
| 374 |
return 0; |
| 375 |
} |
| 376 |
|
| 377 |
static char *filter_path(const char *path, int follow_link) |
| 378 |
{ |
| 379 |
struct stat st; |
| 380 |
int old_errno = errno; |
| 381 |
char tmp_str1[SB_PATH_MAX], tmp_str2[SB_PATH_MAX]; |
| 382 |
char *dname, *bname; |
| 383 |
char *filtered_path; |
| 384 |
|
| 385 |
if (NULL == path) |
| 386 |
return NULL; |
| 387 |
|
| 388 |
filtered_path = malloc(SB_PATH_MAX * sizeof(char)); |
| 389 |
if (NULL == filtered_path) |
| 390 |
return NULL; |
| 391 |
|
| 392 |
if (0 == follow_link) { |
| 393 |
if (-1 == canonicalize(path, filtered_path)) |
| 394 |
return NULL; |
| 395 |
} else { |
| 396 |
/* Basically we get the realpath which should resolve symlinks, |
| 397 |
* etc. If that fails (might not exist), we try to get the |
| 398 |
* realpath of the parent directory, as that should hopefully |
| 399 |
* exist. If all else fails, just go with canonicalize */ |
| 400 |
if (NULL == realpath(path, filtered_path)) { |
| 401 |
snprintf(tmp_str1, SB_PATH_MAX, "%s", path); |
| 402 |
|
| 403 |
dname = dirname(tmp_str1); |
| 404 |
|
| 405 |
/* If not, then check if we can resolve the |
| 406 |
* parent directory */ |
| 407 |
if (NULL == realpath(dname, filtered_path)) { |
| 408 |
/* Fall back to canonicalize */ |
| 409 |
if (-1 == canonicalize(path, filtered_path)) |
| 410 |
return NULL; |
| 411 |
} else { |
| 412 |
/* OK, now add the basename to keep our access |
| 413 |
* checking happy (don't want '/usr/lib' if we |
| 414 |
* tried to do something with non-existing |
| 415 |
* file '/usr/lib/cf*' ...) */ |
| 416 |
snprintf(tmp_str2, SB_PATH_MAX, "%s", path); |
| 417 |
|
| 418 |
bname = basename(tmp_str2); |
| 419 |
snprintf((char *)(filtered_path + strlen(filtered_path)), |
| 420 |
SB_PATH_MAX - strlen(filtered_path), "%s%s", |
| 421 |
(filtered_path[strlen(filtered_path) - 1] != '/') ? "/" : "", |
| 422 |
bname); |
| 423 |
} |
| 424 |
} |
| 425 |
} |
| 426 |
|
| 427 |
errno = old_errno; |
| 428 |
|
| 429 |
return filtered_path; |
| 430 |
} |
| 431 |
|
| 432 |
/* |
| 433 |
* Wrapper Functions |
| 434 |
*/ |
| 435 |
|
| 436 |
int chmod(const char *path, mode_t mode) |
| 437 |
{ |
| 438 |
int result = -1; |
| 439 |
|
| 440 |
if FUNCTION_SANDBOX_SAFE("chmod", path) { |
| 441 |
check_dlsym(chmod); |
| 442 |
result = true_chmod(path, mode); |
| 443 |
} |
| 444 |
|
| 445 |
return result; |
| 446 |
} |
| 447 |
|
| 448 |
int chown(const char *path, uid_t owner, gid_t group) |
| 449 |
{ |
| 450 |
int result = -1; |
| 451 |
|
| 452 |
if FUNCTION_SANDBOX_SAFE("chown", path) { |
| 453 |
check_dlsym(chown); |
| 454 |
result = true_chown(path, owner, group); |
| 455 |
} |
| 456 |
|
| 457 |
return result; |
| 458 |
} |
| 459 |
|
| 460 |
int creat(const char *pathname, mode_t mode) |
| 461 |
{ |
| 462 |
/* Is it a system call? */ |
| 463 |
int result = -1; |
| 464 |
|
| 465 |
if FUNCTION_SANDBOX_SAFE("creat", pathname) { |
| 466 |
check_dlsym(open); |
| 467 |
result = true_open(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 468 |
} |
| 469 |
|
| 470 |
return result; |
| 471 |
} |
| 472 |
|
| 473 |
FILE *fopen(const char *pathname, const char *mode) |
| 474 |
{ |
| 475 |
FILE *result = NULL; |
| 476 |
|
| 477 |
if FUNCTION_SANDBOX_SAFE_OPEN_CHAR("fopen", pathname, mode) { |
| 478 |
check_dlsym(fopen); |
| 479 |
result = true_fopen(pathname, mode); |
| 480 |
} |
| 481 |
|
| 482 |
return result; |
| 483 |
} |
| 484 |
|
| 485 |
int lchown(const char *path, uid_t owner, gid_t group) |
| 486 |
{ |
| 487 |
int result = -1; |
| 488 |
|
| 489 |
if FUNCTION_SANDBOX_SAFE("lchown", path) { |
| 490 |
check_dlsym(lchown); |
| 491 |
result = true_lchown(path, owner, group); |
| 492 |
} |
| 493 |
|
| 494 |
return result; |
| 495 |
} |
| 496 |
|
| 497 |
int link(const char *oldpath, const char *newpath) |
| 498 |
{ |
| 499 |
int result = -1; |
| 500 |
|
| 501 |
if FUNCTION_SANDBOX_SAFE("link", newpath) { |
| 502 |
check_dlsym(link); |
| 503 |
result = true_link(oldpath, newpath); |
| 504 |
} |
| 505 |
|
| 506 |
return result; |
| 507 |
} |
| 508 |
|
| 509 |
int mkdir(const char *pathname, mode_t mode) |
| 510 |
{ |
| 511 |
struct stat st; |
| 512 |
int result = -1, my_errno = errno; |
| 513 |
char canonic[SB_PATH_MAX]; |
| 514 |
|
| 515 |
if (-1 == canonicalize(pathname, canonic)) |
| 516 |
/* Path is too long to canonicalize, do not fail, but just let |
| 517 |
* the real function handle it (see bug #94630 and #21766). */ |
| 518 |
if (ENAMETOOLONG != errno) |
| 519 |
return -1; |
| 520 |
|
| 521 |
/* XXX: Hack to prevent errors if the directory exist, |
| 522 |
* and are not writable - we rather return EEXIST rather |
| 523 |
* than failing */ |
| 524 |
if (0 == lstat(canonic, &st)) { |
| 525 |
errno = EEXIST; |
| 526 |
return -1; |
| 527 |
} |
| 528 |
errno = my_errno; |
| 529 |
|
| 530 |
if FUNCTION_SANDBOX_SAFE("mkdir", pathname) { |
| 531 |
check_dlsym(mkdir); |
| 532 |
result = true_mkdir(pathname, mode); |
| 533 |
} |
| 534 |
|
| 535 |
return result; |
| 536 |
} |
| 537 |
|
| 538 |
DIR *opendir(const char *name) |
| 539 |
{ |
| 540 |
DIR *result = NULL; |
| 541 |
|
| 542 |
if FUNCTION_SANDBOX_SAFE("opendir", name) { |
| 543 |
check_dlsym(opendir); |
| 544 |
result = true_opendir(name); |
| 545 |
} |
| 546 |
|
| 547 |
return result; |
| 548 |
} |
| 549 |
|
| 550 |
#ifdef WRAP_MKNOD |
| 551 |
|
| 552 |
int __xmknod(const char *pathname, mode_t mode, dev_t dev) |
| 553 |
{ |
| 554 |
int result = -1; |
| 555 |
|
| 556 |
if FUNCTION_SANDBOX_SAFE("__xmknod", pathname) { |
| 557 |
check_dlsym(__xmknod); |
| 558 |
result = true___xmknod(pathname, mode, dev); |
| 559 |
} |
| 560 |
|
| 561 |
return result; |
| 562 |
} |
| 563 |
|
| 564 |
#endif |
| 565 |
|
| 566 |
int access(const char *pathname, int mode) |
| 567 |
{ |
| 568 |
int result = -1; |
| 569 |
|
| 570 |
if FUNCTION_SANDBOX_SAFE_ACCESS("access", pathname, mode) { |
| 571 |
check_dlsym(access); |
| 572 |
result = true_access(pathname, mode); |
| 573 |
} |
| 574 |
|
| 575 |
return result; |
| 576 |
} |
| 577 |
|
| 578 |
/* Eventually, there is a third parameter: it's mode_t mode */ |
| 579 |
int open(const char *pathname, int flags, ...) |
| 580 |
{ |
| 581 |
va_list ap; |
| 582 |
mode_t mode = 0; |
| 583 |
int result = -1; |
| 584 |
|
| 585 |
if (flags & O_CREAT) { |
| 586 |
va_start(ap, flags); |
| 587 |
mode = va_arg(ap, mode_t); |
| 588 |
va_end(ap); |
| 589 |
} |
| 590 |
|
| 591 |
if FUNCTION_SANDBOX_SAFE_OPEN_INT("open", pathname, flags) { |
| 592 |
check_dlsym(open); |
| 593 |
result = true_open(pathname, flags, mode); |
| 594 |
} |
| 595 |
|
| 596 |
return result; |
| 597 |
} |
| 598 |
|
| 599 |
int rename(const char *oldpath, const char *newpath) |
| 600 |
{ |
| 601 |
int result = -1; |
| 602 |
|
| 603 |
if (FUNCTION_SANDBOX_SAFE("rename", oldpath) && |
| 604 |
FUNCTION_SANDBOX_SAFE("rename", newpath)) { |
| 605 |
check_dlsym(rename); |
| 606 |
result = true_rename(oldpath, newpath); |
| 607 |
} |
| 608 |
|
| 609 |
return result; |
| 610 |
} |
| 611 |
|
| 612 |
int rmdir(const char *pathname) |
| 613 |
{ |
| 614 |
int result = -1; |
| 615 |
|
| 616 |
if FUNCTION_SANDBOX_SAFE("rmdir", pathname) { |
| 617 |
check_dlsym(rmdir); |
| 618 |
result = true_rmdir(pathname); |
| 619 |
} |
| 620 |
|
| 621 |
return result; |
| 622 |
} |
| 623 |
|
| 624 |
int symlink(const char *oldpath, const char *newpath) |
| 625 |
{ |
| 626 |
int result = -1; |
| 627 |
|
| 628 |
if FUNCTION_SANDBOX_SAFE("symlink", newpath) { |
| 629 |
check_dlsym(symlink); |
| 630 |
result = true_symlink(oldpath, newpath); |
| 631 |
} |
| 632 |
|
| 633 |
return result; |
| 634 |
} |
| 635 |
|
| 636 |
int truncate(const char *path, TRUNCATE_T length) |
| 637 |
{ |
| 638 |
int result = -1; |
| 639 |
|
| 640 |
if FUNCTION_SANDBOX_SAFE("truncate", path) { |
| 641 |
check_dlsym(truncate); |
| 642 |
result = true_truncate(path, length); |
| 643 |
} |
| 644 |
|
| 645 |
return result; |
| 646 |
} |
| 647 |
|
| 648 |
int unlink(const char *pathname) |
| 649 |
{ |
| 650 |
int result = -1; |
| 651 |
char canonic[SB_PATH_MAX]; |
| 652 |
|
| 653 |
if (-1 == canonicalize(pathname, canonic)) |
| 654 |
/* Path is too long to canonicalize, do not fail, but just let |
| 655 |
* the real function handle it (see bug #94630 and #21766). */ |
| 656 |
if (ENAMETOOLONG != errno) |
| 657 |
return -1; |
| 658 |
|
| 659 |
/* XXX: Hack to make sure sandboxed process cannot remove |
| 660 |
* a device node, bug #79836. */ |
| 661 |
if ((0 == strncmp(canonic, "/dev/null", 9)) || |
| 662 |
(0 == strncmp(canonic, "/dev/zero", 9))) { |
| 663 |
errno = EACCES; |
| 664 |
return result; |
| 665 |
} |
| 666 |
|
| 667 |
if FUNCTION_SANDBOX_SAFE("unlink", pathname) { |
| 668 |
check_dlsym(unlink); |
| 669 |
result = true_unlink(pathname); |
| 670 |
} |
| 671 |
|
| 672 |
return result; |
| 673 |
} |
| 674 |
|
| 675 |
#if (GLIBC_MINOR >= 1) |
| 676 |
|
| 677 |
int creat64(const char *pathname, __mode_t mode) |
| 678 |
{ |
| 679 |
/* Is it a system call? */ |
| 680 |
int result = -1; |
| 681 |
|
| 682 |
if FUNCTION_SANDBOX_SAFE("creat64", pathname) { |
| 683 |
check_dlsym(open64); |
| 684 |
result = true_open64(pathname, O_CREAT | O_WRONLY | O_TRUNC, mode); |
| 685 |
} |
| 686 |
|
| 687 |
return result; |
| 688 |
} |
| 689 |
|
| 690 |
FILE *fopen64(const char *pathname, const char *mode) |
| 691 |
{ |
| 692 |
FILE *result = NULL; |
| 693 |
|
| 694 |
if FUNCTION_SANDBOX_SAFE_OPEN_CHAR("fopen64", pathname, mode) { |
| 695 |
check_dlsym(fopen64); |
| 696 |
result = true_fopen64(pathname, mode); |
| 697 |
} |
| 698 |
|
| 699 |
return result; |
| 700 |
} |
| 701 |
|
| 702 |
/* Eventually, there is a third parameter: it's mode_t mode */ |
| 703 |
int open64(const char *pathname, int flags, ...) |
| 704 |
{ |
| 705 |
va_list ap; |
| 706 |
mode_t mode = 0; |
| 707 |
int result = -1; |
| 708 |
|
| 709 |
if (flags & O_CREAT) { |
| 710 |
va_start(ap, flags); |
| 711 |
mode = va_arg(ap, mode_t); |
| 712 |
va_end(ap); |
| 713 |
} |
| 714 |
|
| 715 |
if FUNCTION_SANDBOX_SAFE_OPEN_INT("open64", pathname, flags) { |
| 716 |
check_dlsym(open64); |
| 717 |
result = true_open64(pathname, flags, mode); |
| 718 |
} |
| 719 |
|
| 720 |
return result; |
| 721 |
} |
| 722 |
|
| 723 |
int truncate64(const char *path, __off64_t length) |
| 724 |
{ |
| 725 |
int result = -1; |
| 726 |
|
| 727 |
if FUNCTION_SANDBOX_SAFE("truncate64", path) { |
| 728 |
check_dlsym(truncate64); |
| 729 |
result = true_truncate64(path, length); |
| 730 |
} |
| 731 |
|
| 732 |
return result; |
| 733 |
} |
| 734 |
|
| 735 |
#endif /* GLIBC_MINOR >= 1 */ |
| 736 |
|
| 737 |
/* |
| 738 |
* Exec Wrappers |
| 739 |
*/ |
| 740 |
|
| 741 |
int execve(const char *filename, char *const argv[], char *const envp[]) |
| 742 |
{ |
| 743 |
int old_errno = errno; |
| 744 |
int result = -1; |
| 745 |
int count = 0; |
| 746 |
int env_len = 0; |
| 747 |
char **my_env = NULL; |
| 748 |
int kill_env = 1; |
| 749 |
/* We limit the size LD_PRELOAD can be here, but it should be enough */ |
| 750 |
char tmp_str[SB_BUF_LEN]; |
| 751 |
|
| 752 |
if FUNCTION_SANDBOX_SAFE("execve", filename) { |
| 753 |
while (envp[count] != NULL) { |
| 754 |
/* Check if we do not have to do anything */ |
| 755 |
if (strstr(envp[count], LD_PRELOAD_EQ) == envp[count]) { |
| 756 |
if (NULL != strstr(envp[count], sandbox_lib)) { |
| 757 |
my_env = (char **)envp; |
| 758 |
kill_env = 0; |
| 759 |
goto end_loop; |
| 760 |
} |
| 761 |
} |
| 762 |
|
| 763 |
/* If LD_PRELOAD is set and sandbox_lib not in it */ |
| 764 |
if (((strstr(envp[count], LD_PRELOAD_EQ) == envp[count]) && |
| 765 |
(NULL == strstr(envp[count], sandbox_lib))) || |
| 766 |
/* Or LD_PRELOAD is not set, and this is the last loop */ |
| 767 |
((strstr(envp[count], LD_PRELOAD_EQ) != envp[count]) && |
| 768 |
(NULL == envp[count + 1]))) { |
| 769 |
int i = 0; |
| 770 |
int add_ldpreload = 0; |
| 771 |
const int max_envp_len = strlen(envp[count]) + strlen(sandbox_lib) + 1; |
| 772 |
|
| 773 |
/* Fail safe ... */ |
| 774 |
if (max_envp_len > SB_BUF_LEN) { |
| 775 |
fprintf(stderr, "sandbox: max_envp_len too big!\n"); |
| 776 |
errno = ENOMEM; |
| 777 |
return result; |
| 778 |
} |
| 779 |
|
| 780 |
/* Calculate envp size */ |
| 781 |
my_env = (char **)envp; |
| 782 |
do |
| 783 |
env_len++; |
| 784 |
while (NULL != *my_env++); |
| 785 |
|
| 786 |
/* Should we add LD_PRELOAD ? */ |
| 787 |
if (strstr(envp[count], LD_PRELOAD_EQ) != envp[count]) |
| 788 |
add_ldpreload = 1; |
| 789 |
|
| 790 |
my_env = (char **)calloc(env_len + add_ldpreload, sizeof(char *)); |
| 791 |
if (NULL == my_env) { |
| 792 |
errno = ENOMEM; |
| 793 |
return result; |
| 794 |
} |
| 795 |
/* Copy envp to my_env */ |
| 796 |
do |
| 797 |
/* Leave a space for LD_PRELOAD if needed */ |
| 798 |
my_env[i + add_ldpreload] = envp[i]; |
| 799 |
while (NULL != envp[i++]); |
| 800 |
|
| 801 |
/* Add 'LD_PRELOAD=' to the beginning of our new string */ |
| 802 |
snprintf(tmp_str, max_envp_len, "%s%s", LD_PRELOAD_EQ, sandbox_lib); |
| 803 |
|
| 804 |
/* LD_PRELOAD already have variables other than sandbox_lib, |
| 805 |
* thus we have to add sandbox_lib seperated via a whitespace. */ |
| 806 |
if (0 == add_ldpreload) { |
| 807 |
snprintf((char *)(tmp_str + strlen(tmp_str)), |
| 808 |
max_envp_len - strlen(tmp_str) + 1, " %s", |
| 809 |
(char *)(envp[count] + strlen(LD_PRELOAD_EQ))); |
| 810 |
} |
| 811 |
|
| 812 |
/* Valid string? */ |
| 813 |
tmp_str[max_envp_len] = '\0'; |
| 814 |
|
| 815 |
/* Ok, replace my_env[count] with our version that contains |
| 816 |
* sandbox_lib ... */ |
| 817 |
if (1 == add_ldpreload) |
| 818 |
/* We reserved a space for LD_PRELOAD above */ |
| 819 |
my_env[0] = tmp_str; |
| 820 |
else |
| 821 |
my_env[count] = tmp_str; |
| 822 |
|
| 823 |
goto end_loop; |
| 824 |
} |
| 825 |
count++; |
| 826 |
} |
| 827 |
|
| 828 |
end_loop: |
| 829 |
errno = old_errno; |
| 830 |
check_dlsym(execve); |
| 831 |
result = true_execve(filename, argv, my_env); |
| 832 |
old_errno = errno; |
| 833 |
|
| 834 |
if (my_env && kill_env) |
| 835 |
free(my_env); |
| 836 |
} |
| 837 |
|
| 838 |
errno = old_errno; |
| 839 |
|
| 840 |
return result; |
| 841 |
} |
| 842 |
|
| 843 |
/* |
| 844 |
* Internal Functions |
| 845 |
*/ |
| 846 |
|
| 847 |
#if (GLIBC_MINOR == 1) |
| 848 |
|
| 849 |
/* This hack is needed for glibc 2.1.1 (and others?) |
| 850 |
* (not really needed, but good example) */ |
| 851 |
extern int fclose(FILE *); |
| 852 |
static int (*true_fclose) (FILE *) = NULL; |
| 853 |
int fclose(FILE * file) |
| 854 |
{ |
| 855 |
int result = -1; |
| 856 |
|
| 857 |
check_dlsym(fclose); |
| 858 |
result = true_fclose(file); |
| 859 |
|
| 860 |
return result; |
| 861 |
} |
| 862 |
|
| 863 |
#endif /* GLIBC_MINOR == 1 */ |
| 864 |
|
| 865 |
static void init_context(sbcontext_t * context) |
| 866 |
{ |
| 867 |
context->show_access_violation = 1; |
| 868 |
context->deny_prefixes = NULL; |
| 869 |
context->num_deny_prefixes = 0; |
| 870 |
context->read_prefixes = NULL; |
| 871 |
context->num_read_prefixes = 0; |
| 872 |
context->write_prefixes = NULL; |
| 873 |
context->num_write_prefixes = 0; |
| 874 |
context->predict_prefixes = NULL; |
| 875 |
context->num_predict_prefixes = 0; |
| 876 |
context->write_denied_prefixes = NULL; |
| 877 |
context->num_write_denied_prefixes = 0; |
| 878 |
} |
| 879 |
|
| 880 |
static int is_sandbox_pid() |
| 881 |
{ |
| 882 |
int old_errno = errno; |
| 883 |
int result = 0; |
| 884 |
FILE *pids_stream = NULL; |
| 885 |
int pids_file = -1; |
| 886 |
int current_pid = 0; |
| 887 |
int tmp_pid = 0; |
| 888 |
|
| 889 |
init_wrappers(); |
| 890 |
|
| 891 |
check_dlsym(fopen); |
| 892 |
pids_stream = true_fopen(sandbox_pids_file, "r"); |
| 893 |
|
| 894 |
if (NULL == pids_stream) { |
| 895 |
perror(">>> pids file fopen"); |
| 896 |
} else { |
| 897 |
pids_file = fileno(pids_stream); |
| 898 |
|
| 899 |
if (pids_file < 0) { |
| 900 |
perror(">>> pids file fileno"); |
| 901 |
} else { |
| 902 |
current_pid = getpid(); |
| 903 |
|
| 904 |
while (EOF != fscanf(pids_stream, "%d\n", &tmp_pid)) { |
| 905 |
if (tmp_pid == current_pid) { |
| 906 |
result = 1; |
| 907 |
break; |
| 908 |
} |
| 909 |
} |
| 910 |
} |
| 911 |
if (EOF == fclose(pids_stream)) { |
| 912 |
perror(">>> pids file fclose"); |
| 913 |
} |
| 914 |
pids_stream = NULL; |
| 915 |
pids_file = -1; |
| 916 |
} |
| 917 |
|
| 918 |
errno = old_errno; |
| 919 |
|
| 920 |
return result; |
| 921 |
} |
| 922 |
|
| 923 |
static void clean_env_entries(char ***prefixes_array, int *prefixes_num) |
| 924 |
{ |
| 925 |
int old_errno = errno; |
| 926 |
int i = 0; |
| 927 |
|
| 928 |
if (NULL != *prefixes_array) { |
| 929 |
for (i = 0; i < *prefixes_num; i++) { |
| 930 |
if (NULL != (*prefixes_array)[i]) { |
| 931 |
free((*prefixes_array)[i]); |
| 932 |
(*prefixes_array)[i] = NULL; |
| 933 |
} |
| 934 |
} |
| 935 |
if (NULL != *prefixes_array) |
| 936 |
free(*prefixes_array); |
| 937 |
*prefixes_array = NULL; |
| 938 |
*prefixes_num = 0; |
| 939 |
} |
| 940 |
|
| 941 |
errno = old_errno; |
| 942 |
} |
| 943 |
|
| 944 |
#define pfx_num (*prefixes_num) |
| 945 |
#define pfx_array (*prefixes_array) |
| 946 |
#define pfx_item ((*prefixes_array)[(*prefixes_num)]) |
| 947 |
|
| 948 |
static void init_env_entries(char ***prefixes_array, int *prefixes_num, const char *env, const char *prefixes_env, int warn) |
| 949 |
{ |
| 950 |
int old_errno = errno; |
| 951 |
// char *prefixes_env = getenv(env); |
| 952 |
|
| 953 |
if (NULL == prefixes_env) { |
| 954 |
/* Do not warn if this is in init stage, as we might get |
| 955 |
* issues due to LD_PRELOAD already set (bug #91431). */ |
| 956 |
if (1 == sb_init) |
| 957 |
fprintf(stderr, "Sandbox error : the %s environmental variable should be defined.\n", env); |
| 958 |
if(pfx_array) { |
| 959 |
int x; |
| 960 |
for(x=0; x < pfx_num; x++) |
| 961 |
free(pfx_item); |
| 962 |
free(pfx_array); |
| 963 |
} |
| 964 |
pfx_num = 0; |
| 965 |
} else { |
| 966 |
char *buffer = NULL; |
| 967 |
char *buffer_ptr = NULL; |
| 968 |
int prefixes_env_length = strlen(prefixes_env); |
| 969 |
int i = 0; |
| 970 |
int num_delimiters = 0; |
| 971 |
char *token = NULL; |
| 972 |
char *rpath = NULL; |
| 973 |
|
| 974 |
for (i = 0; i < prefixes_env_length; i++) { |
| 975 |
if (':' == prefixes_env[i]) { |
| 976 |
num_delimiters++; |
| 977 |
} |
| 978 |
} |
| 979 |
|
| 980 |
if (num_delimiters > 0) { |
| 981 |
pfx_array = malloc(((num_delimiters * 2) + 1) * sizeof(char *)); |
| 982 |
if (NULL == pfx_array) |
| 983 |
return; |
| 984 |
buffer = strndup(prefixes_env, prefixes_env_length); |
| 985 |
if (NULL == buffer) |
| 986 |
return; |
| 987 |
buffer_ptr = buffer; |
| 988 |
|
| 989 |
#ifdef REENTRANT_STRTOK |
| 990 |
token = strtok_r(buffer_ptr, ":", &buffer_ptr); |
| 991 |
#else |
| 992 |
token = strtok(buffer_ptr, ":"); |
| 993 |
#endif |
| 994 |
|
| 995 |
while ((NULL != token) && (strlen(token) > 0)) { |
| 996 |
pfx_item = filter_path(token, 0); |
| 997 |
if (NULL != pfx_item) { |
| 998 |
pfx_num++; |
| 999 |
|
| 1000 |
/* Now add the realpath if it exists and |
| 1001 |
* are not a duplicate */ |
| 1002 |
rpath = malloc(SB_PATH_MAX * sizeof(char)); |
| 1003 |
if (NULL != rpath) { |
| 1004 |
pfx_item = realpath(*(&(pfx_item) - 1), rpath); |
| 1005 |
if ((NULL != pfx_item) && |
| 1006 |
(0 != strcmp(*(&(pfx_item) - 1), pfx_item))) { |
| 1007 |
pfx_num++; |
| 1008 |
} else { |
| 1009 |
free(rpath); |
| 1010 |
pfx_item = NULL; |
| 1011 |
} |
| 1012 |
} |
| 1013 |
} |
| 1014 |
|
| 1015 |
#ifdef REENTRANT_STRTOK |
| 1016 |
token = strtok_r(NULL, ":", &buffer_ptr); |
| 1017 |
#else |
| 1018 |
token = strtok(NULL, ":"); |
| 1019 |
#endif |
| 1020 |
} |
| 1021 |
|
| 1022 |
free(buffer); |
| 1023 |
} else if (prefixes_env_length > 0) { |
| 1024 |
pfx_array = malloc(2 * sizeof(char *)); |
| 1025 |
if (NULL == pfx_array) |
| 1026 |
return; |
| 1027 |
|
| 1028 |
pfx_item = filter_path(prefixes_env, 0); |
| 1029 |
if (NULL != pfx_item) { |
| 1030 |
pfx_num++; |
| 1031 |
|
| 1032 |
/* Now add the realpath if it exists and |
| 1033 |
* are not a duplicate */ |
| 1034 |
rpath = malloc(SB_PATH_MAX * sizeof(char)); |
| 1035 |
if (NULL != rpath) { |
| 1036 |
pfx_item = realpath(*(&(pfx_item) - 1), rpath); |
| 1037 |
if ((NULL != pfx_item) && |
| 1038 |
(0 != strcmp(*(&(pfx_item) - 1), pfx_item))) { |
| 1039 |
pfx_num++; |
| 1040 |
} else { |
| 1041 |
free(rpath); |
| 1042 |
pfx_item = NULL; |
| 1043 |
} |
| 1044 |
} |
| 1045 |
} |
| 1046 |
} |
| 1047 |
} |
| 1048 |
|
| 1049 |
errno = old_errno; |
| 1050 |
} |
| 1051 |
|
| 1052 |
static int check_access(sbcontext_t * sbcontext, const char *func, const char *path, const char *fpath) |
| 1053 |
{ |
| 1054 |
int old_errno = errno; |
| 1055 |
int result = -1; |
| 1056 |
int i = 0; |
| 1057 |
|
| 1058 |
if ((-1 == result) && (NULL != sbcontext->deny_prefixes)) { |
| 1059 |
for (i = 0; i < sbcontext->num_deny_prefixes; i++) { |
| 1060 |
if (NULL != sbcontext->deny_prefixes[i]) { |
| 1061 |
if (0 == strncmp(fpath, |
| 1062 |
sbcontext->deny_prefixes[i], |
| 1063 |
strlen(sbcontext->deny_prefixes[i]))) { |
| 1064 |
result = 0; |
| 1065 |
break; |
| 1066 |
} |
| 1067 |
} |
| 1068 |
} |
| 1069 |
} |
| 1070 |
|
| 1071 |
if (-1 == result) { |
| 1072 |
if ((NULL != sbcontext->read_prefixes) && |
| 1073 |
((0 == strncmp(func, "access_rd", 9)) || |
| 1074 |
(0 == strncmp(func, "open_rd", 7)) || |
| 1075 |
(0 == strncmp(func, "popen", 5)) || |
| 1076 |
(0 == strncmp(func, "opendir", 7)) || |
| 1077 |
(0 == strncmp(func, "system", 6)) || |
| 1078 |
(0 == strncmp(func, "execl", 5)) || |
| 1079 |
(0 == strncmp(func, "execlp", 6)) || |
| 1080 |
(0 == strncmp(func, "execle", 6)) || |
| 1081 |
(0 == strncmp(func, "execv", 5)) || |
| 1082 |
(0 == strncmp(func, "execvp", 6)) || |
| 1083 |
(0 == strncmp(func, "execve", 6)))) { |
| 1084 |
for (i = 0; i < sbcontext->num_read_prefixes; i++) { |
| 1085 |
if (NULL != sbcontext->read_prefixes[i]) { |
| 1086 |
if (0 == strncmp(fpath, |
| 1087 |
sbcontext->read_prefixes[i], |
| 1088 |
strlen(sbcontext->read_prefixes[i]))) { |
| 1089 |
result = 1; |
| 1090 |
break; |
| 1091 |
} |
| 1092 |
} |
| 1093 |
} |
| 1094 |
} |
| 1095 |
if ((NULL != sbcontext->write_prefixes) && |
| 1096 |
((0 == strncmp(func, "access_wr", 7)) || |
| 1097 |
(0 == strncmp(func, "open_wr", 7)) || |
| 1098 |
(0 == strncmp(func, "creat", 5)) || |
| 1099 |
(0 == strncmp(func, "creat64", 7)) || |
| 1100 |
(0 == strncmp(func, "mkdir", 5)) || |
| 1101 |
(0 == strncmp(func, "mknod", 5)) || |
| 1102 |
(0 == strncmp(func, "mkfifo", 6)) || |
| 1103 |
(0 == strncmp(func, "link", 4)) || |
| 1104 |
(0 == strncmp(func, "symlink", 7)) || |
| 1105 |
(0 == strncmp(func, "rename", 6)) || |
| 1106 |
(0 == strncmp(func, "utime", 5)) || |
| 1107 |
(0 == strncmp(func, "utimes", 6)) || |
| 1108 |
(0 == strncmp(func, "unlink", 6)) || |
| 1109 |
(0 == strncmp(func, "rmdir", 5)) || |
| 1110 |
(0 == strncmp(func, "chown", 5)) || |
| 1111 |
(0 == strncmp(func, "lchown", 6)) || |
| 1112 |
(0 == strncmp(func, "chmod", 5)) || |
| 1113 |
(0 == strncmp(func, "truncate", 8)) || |
| 1114 |
(0 == strncmp(func, "ftruncate", 9)) || |
| 1115 |
(0 == strncmp(func, "truncate64", 10)) || |
| 1116 |
(0 == strncmp(func, "ftruncate64", 11)))) { |
| 1117 |
struct stat st; |
| 1118 |
|
| 1119 |
/* No need to check here, as we do it above |
| 1120 |
if (NULL != sbcontext->write_prefixes) { */ |
| 1121 |
|
| 1122 |
if (NULL != sbcontext->write_denied_prefixes) { |
| 1123 |
for (i = 0; i < sbcontext->num_write_denied_prefixes; i++) { |
| 1124 |
if (NULL != sbcontext->write_denied_prefixes[i]) { |
| 1125 |
if (0 == strncmp(fpath, |
| 1126 |
sbcontext->write_denied_prefixes[i], |
| 1127 |
strlen(sbcontext->write_denied_prefixes[i]))) { |
| 1128 |
/* Special paths in writable context that should |
| 1129 |
* be denied - not implemented yet */ |
| 1130 |
result = 0; |
| 1131 |
break; |
| 1132 |
} |
| 1133 |
} |
| 1134 |
} |
| 1135 |
} |
| 1136 |
|
| 1137 |
if ((-1 == result) && (NULL != sbcontext->write_prefixes)) { |
| 1138 |
for (i = 0; i < sbcontext->num_write_prefixes; i++) { |
| 1139 |
if (NULL != sbcontext->write_prefixes[i]) { |
| 1140 |
if (0 == strncmp(fpath, |
| 1141 |
sbcontext->write_prefixes[i], |
| 1142 |
strlen(sbcontext->write_prefixes[i]))) { |
| 1143 |
/* Falls in a writable path */ |
| 1144 |
result = 1; |
| 1145 |
break; |
| 1146 |
} |
| 1147 |
} |
| 1148 |
} |
| 1149 |
} |
| 1150 |
|
| 1151 |
/* XXX: Hack to enable us to remove symlinks pointing |
| 1152 |
* to protected stuff. First we make sure that the |
| 1153 |
* passed path is writable, and if so, check if its a |
| 1154 |
* symlink, and give access only if the resolved path |
| 1155 |
* of the symlink's parent also have write access. */ |
| 1156 |
if ((-1 == result) && |
| 1157 |
((0 == strncmp(func, "unlink", 6)) || |
| 1158 |
(0 == strncmp(func, "lchown", 6)) || |
| 1159 |
(0 == strncmp(func, "rename", 6))) && |
| 1160 |
((-1 != lstat(path, &st)) && (S_ISLNK(st.st_mode)))) { |
| 1161 |
int hresult = -1; |
| 1162 |
|
| 1163 |
/* Check if the symlink unresolved path have access */ |
| 1164 |
for (i = 0; i < sbcontext->num_write_prefixes; i++) { |
| 1165 |
if (NULL != sbcontext->write_prefixes[i]) { |
| 1166 |
if (0 == strncmp(path, |
| 1167 |
sbcontext->write_prefixes[i], |
| 1168 |
strlen(sbcontext->write_prefixes[i]))) { |
| 1169 |
/* Does have write access on path */ |
| 1170 |
hresult = 1; |
| 1171 |
break; |
| 1172 |
} |
| 1173 |
} |
| 1174 |
} |
| 1175 |
if (1 == hresult) { |
| 1176 |
char tmp_buf[SB_PATH_MAX]; |
| 1177 |
char *dname, *rpath; |
| 1178 |
|
| 1179 |
snprintf(tmp_buf, SB_PATH_MAX, "%s", path); |
| 1180 |
|
| 1181 |
dname = dirname(tmp_buf); |
| 1182 |
/* Get symlink resolved path */ |
| 1183 |
rpath = filter_path(dname, 1); |
| 1184 |
if (NULL == rpath) |
| 1185 |
/* Don't really worry here about |
| 1186 |
* memory issues */ |
| 1187 |
goto unlink_hack_end; |
| 1188 |
|
| 1189 |
/* Now check if the symlink resolved path have access */ |
| 1190 |
for (i = 0; i < sbcontext->num_write_prefixes; i++) { |
| 1191 |
if (NULL != sbcontext->write_prefixes[i]) { |
| 1192 |
if (0 == strncmp(rpath, |
| 1193 |
sbcontext->write_prefixes[i], |
| 1194 |
strlen(sbcontext->write_prefixes[i]))) { |
| 1195 |
/* Does have write access on path */ |
| 1196 |
hresult = 2; |
| 1197 |
break; |
| 1198 |
} |
| 1199 |
} |
| 1200 |
} |
| 1201 |
free(rpath); |
| 1202 |
|
| 1203 |
if (2 == hresult) { |
| 1204 |
/* Ok, enable the hack as it is a symlink */ |
| 1205 |
result = 1; |
| 1206 |
} |
| 1207 |
} |
| 1208 |
} |
| 1209 |
unlink_hack_end: |
| 1210 |
|
| 1211 |
/* XXX: Hack to allow writing to '/proc/self/fd' (bug #91516) |
| 1212 |
* It needs to be here, as for each process '/proc/self' |
| 1213 |
* will differ ... */ |
| 1214 |
if (-1 == result) { |
| 1215 |
char proc_self_fd[SB_PATH_MAX]; |
| 1216 |
|
| 1217 |
if (NULL != realpath("/proc/self/fd", proc_self_fd)) { |
| 1218 |
if (0 == strncmp(fpath, proc_self_fd, strlen(proc_self_fd))) |
| 1219 |
result = 1; |
| 1220 |
} |
| 1221 |
} |
| 1222 |
|
| 1223 |
if ((-1 == result) && (NULL != sbcontext->predict_prefixes)) { |
| 1224 |
for (i = 0; i < sbcontext->num_predict_prefixes; i++) { |
| 1225 |
if (NULL != sbcontext->predict_prefixes[i]) { |
| 1226 |
if (0 == strncmp(fpath, |
| 1227 |
sbcontext->predict_prefixes[i], |
| 1228 |
strlen(sbcontext->predict_prefixes[i]))) { |
| 1229 |
/* Is a known access violation, so deny access, |
| 1230 |
* and do not log it */ |
| 1231 |
sbcontext->show_access_violation = 0; |
| 1232 |
result = 0; |
| 1233 |
break; |
| 1234 |
} |
| 1235 |
} |
| 1236 |
} |
| 1237 |
} |
| 1238 |
} |
| 1239 |
} |
| 1240 |
|
| 1241 |
if (-1 == result) { |
| 1242 |
result = 0; |
| 1243 |
} |
| 1244 |
|
| 1245 |
errno = old_errno; |
| 1246 |
|
| 1247 |
return result; |
| 1248 |
} |
| 1249 |
|
| 1250 |
static int check_syscall(sbcontext_t * sbcontext, const char *func, const char *file) |
| 1251 |
{ |
| 1252 |
int old_errno = errno; |
| 1253 |
int result = 1; |
| 1254 |
struct stat log_stat; |
| 1255 |
char *log_path = NULL; |
| 1256 |
char *absolute_path = NULL; |
| 1257 |
char *resolved_path = NULL; |
| 1258 |
char *tmp_buffer = NULL; |
| 1259 |
int log_file = 0; |
| 1260 |
struct stat debug_log_stat; |
| 1261 |
char *debug_log_env = NULL; |
| 1262 |
char *debug_log_path = NULL; |
| 1263 |
int debug_log_file = 0; |
| 1264 |
char buffer[512]; |
| 1265 |
char *dpath = NULL; |
| 1266 |
|
| 1267 |
init_wrappers(); |
| 1268 |
|
| 1269 |
absolute_path = filter_path(file, 0); |
| 1270 |
if (NULL == absolute_path) |
| 1271 |
goto fp_error; |
| 1272 |
resolved_path = filter_path(file, 1); |
| 1273 |
if (NULL == resolved_path) |
| 1274 |
goto fp_error; |
| 1275 |
|
| 1276 |
log_path = getenv("SANDBOX_LOG"); |
| 1277 |
debug_log_env = getenv("SANDBOX_DEBUG"); |
| 1278 |
debug_log_path = getenv("SANDBOX_DEBUG_LOG"); |
| 1279 |
|
| 1280 |
if (((NULL == log_path) || |
| 1281 |
(0 != strncmp(absolute_path, log_path, strlen(log_path)))) && |
| 1282 |
((NULL == debug_log_env) || |
| 1283 |
(NULL == debug_log_path) || |
| 1284 |
(0 != strncmp(absolute_path, debug_log_path, strlen(debug_log_path)))) && |
| 1285 |
(0 == check_access(sbcontext, func, absolute_path, resolved_path))) { |
| 1286 |
if (1 == sbcontext->show_access_violation) { |
| 1287 |
fprintf(stderr, "\e[31;01mACCESS DENIED\033[0m %s:%*s%s\n", |
| 1288 |
func, (int)(10 - strlen(func)), "", absolute_path); |
| 1289 |
|
| 1290 |
if (NULL != log_path) { |
| 1291 |
if (0 != strncmp(absolute_path, resolved_path, strlen(absolute_path))) { |
| 1292 |
sprintf(buffer, "%s:%*s%s (symlink to %s)\n", func, (int)(10-strlen(func)), "", |
| 1293 |
absolute_path, resolved_path); |
| 1294 |
} else { |
| 1295 |
sprintf(buffer, "%s:%*s%s\n", func, (int)(10 - strlen(func)), "", absolute_path); |
| 1296 |
} |
| 1297 |
// log_path somehow gets corrupted. figuring out why would be good. |
| 1298 |
dpath = strdup(log_path); |
| 1299 |
if ((0 == lstat(log_path, &log_stat)) && |
| 1300 |
(0 == S_ISREG(log_stat.st_mode))) { |
| 1301 |
fprintf(stderr, "\e[31;01mSECURITY BREACH\033[0m %s already exists and is not a regular file.\n", dpath); |
| 1302 |
} else if (0 == check_access(sbcontext, "open_wr", dpath, filter_path(dpath, 1))) { |
| 1303 |
unsetenv("SANDBOX_LOG"); |
| 1304 |
fprintf(stderr, "\e[31;01mSECURITY BREACH\033[0m SANDBOX_LOG %s isn't allowed via SANDBOX_WRITE\n", dpath); |
| 1305 |
} else { |
| 1306 |
check_dlsym(open); |
| 1307 |
log_file = true_open(dpath, O_APPEND | O_WRONLY | O_CREAT, S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); |
| 1308 |
if (log_file >= 0) { |
| 1309 |
write(log_file, buffer, strlen(buffer)); |
| 1310 |
close(log_file); |
| 1311 |
} |
| 1312 |
} |
| 1313 |
free(dpath); |
| 1314 |
} |
| 1315 |
} |
| 1316 |
|
| 1317 |
result = 0; |
| 1318 |
} else if (NULL != debug_log_env) { |
| 1319 |
if (NULL != debug_log_path) { |
| 1320 |
if (0 != strncmp(absolute_path, debug_log_path, strlen(debug_log_path))) { |
| 1321 |
sprintf(buffer, "%s:%*s%s\n", func, (int)(10 - strlen(func)), "", absolute_path); |
| 1322 |
//debug_log_path somehow gets corupted, same thing as log_path above. |
| 1323 |
dpath = strdup(debug_log_path); |
| 1324 |
if ((0 == lstat(debug_log_path, &debug_log_stat)) |
| 1325 |
&& (0 == S_ISREG(debug_log_stat.st_mode))) { |
| 1326 |
fprintf(stderr, "\e[31;01mSECURITY BREACH\033[0m %s already exists and is not a regular file.\n", |
| 1327 |
debug_log_path); |
| 1328 |
} else if (0 == check_access(sbcontext, "open_wr", dpath, filter_path(dpath, 1))) { |
| 1329 |
unsetenv("SANDBOX_DEBUG"); |
| 1330 |
unsetenv("SANDBOX_DEBUG_LOG"); |
| 1331 |
fprintf(stderr, "\e[31;01mSECURITY BREACH\033[0m SANDBOX_DEBUG_LOG %s isn't allowed by SANDBOX_WRITE.\n", |
| 1332 |
dpath); |
| 1333 |
} else { |
| 1334 |
check_dlsym(open); |
| 1335 |
debug_log_file = true_open(dpath, O_APPEND | O_WRONLY | O_CREAT, |
| 1336 |
S_IRUSR | S_IWUSR | S_IRGRP | S_IROTH); |
| 1337 |
if (debug_log_file >= 0) { |
| 1338 |
write(debug_log_file, buffer, strlen(buffer)); |
| 1339 |
close(debug_log_file); |
| 1340 |
} |
| 1341 |
} |
| 1342 |
free(dpath); |
| 1343 |
} |
| 1344 |
} else { |
| 1345 |
fprintf(stderr, "\e[32;01mACCESS ALLOWED\033[0m %s:%*s%s\n", |
| 1346 |
func, (int)(10 - strlen(func)), "", absolute_path); |
| 1347 |
} |
| 1348 |
} |
| 1349 |
|
| 1350 |
if (NULL != absolute_path) |
| 1351 |
free(absolute_path); |
| 1352 |
if (NULL != resolved_path) |
| 1353 |
free(resolved_path); |
| 1354 |
|
| 1355 |
errno = old_errno; |
| 1356 |
|
| 1357 |
return result; |
| 1358 |
|
| 1359 |
fp_error: |
| 1360 |
if (NULL != absolute_path) |
| 1361 |
free(absolute_path); |
| 1362 |
if (NULL != resolved_path) |
| 1363 |
free(resolved_path); |
| 1364 |
|
| 1365 |
/* The path is too long to be canonicalized, so just warn and let the |
| 1366 |
* function handle it (see bug #94630 and #21766 for more info) */ |
| 1367 |
if (ENAMETOOLONG == errno) { |
| 1368 |
if (0 == sb_path_size_warning) { |
| 1369 |
fprintf(stderr, "\e[31;01mPATH LENGTH\033[0m %s:%*s%s\n", |
| 1370 |
func, (int)(10 - strlen(func)), "", file); |
| 1371 |
sb_path_size_warning = 1; |
| 1372 |
} |
| 1373 |
|
| 1374 |
return 1; |
| 1375 |
} |
| 1376 |
|
| 1377 |
return 0; |
| 1378 |
} |
| 1379 |
|
| 1380 |
static int is_sandbox_on() |
| 1381 |
{ |
| 1382 |
int old_errno = errno; |
| 1383 |
|
| 1384 |
/* $SANDBOX_ACTIVE is an env variable that should ONLY |
| 1385 |
* be used internal by sandbox.c and libsanbox.c. External |
| 1386 |
* sources should NEVER set it, else the sandbox is enabled |
| 1387 |
* in some cases when run in parallel with another sandbox, |
| 1388 |
* but not even in the sandbox shell. |
| 1389 |
* |
| 1390 |
* Azarah (3 Aug 2002) |
| 1391 |
*/ |
| 1392 |
if ((NULL != getenv("SANDBOX_ON")) && |
| 1393 |
(0 == strncmp(getenv("SANDBOX_ON"), "1", 1)) && |
| 1394 |
(NULL != getenv("SANDBOX_ACTIVE")) && |
| 1395 |
(0 == strncmp(getenv("SANDBOX_ACTIVE"), "armedandready", 13))) { |
| 1396 |
errno = old_errno; |
| 1397 |
return 1; |
| 1398 |
} else { |
| 1399 |
errno = old_errno; |
| 1400 |
return 0; |
| 1401 |
} |
| 1402 |
} |
| 1403 |
|
| 1404 |
static int before_syscall(const char *func, const char *file) |
| 1405 |
{ |
| 1406 |
int old_errno = errno; |
| 1407 |
int result = 1; |
| 1408 |
// static sbcontext_t sbcontext; |
| 1409 |
char *deny = getenv("SANDBOX_DENY"); |
| 1410 |
char *read = getenv("SANDBOX_READ"); |
| 1411 |
char *write = getenv("SANDBOX_WRITE"); |
| 1412 |
char *predict = getenv("SANDBOX_PREDICT"); |
| 1413 |
|
| 1414 |
if (NULL == file || 0 == strlen(file)) { |
| 1415 |
/* The file/directory does not exist */ |
| 1416 |
errno = ENOENT; |
| 1417 |
return 0; |
| 1418 |
} |
| 1419 |
|
| 1420 |
if(sb_init == 0) { |
| 1421 |
init_context(&sbcontext); |
| 1422 |
cached_env_vars = malloc(sizeof(char *)*4); |
| 1423 |
cached_env_vars[0] = cached_env_vars[1] = cached_env_vars[2] = cached_env_vars[3] = NULL; |
| 1424 |
sb_init=1; |
| 1425 |
} |
| 1426 |
|
| 1427 |
if((deny == NULL && cached_env_vars[0] != deny) || cached_env_vars[0] == NULL || |
| 1428 |
strcmp(cached_env_vars[0], deny) != 0) { |
| 1429 |
|
| 1430 |
clean_env_entries(&(sbcontext.deny_prefixes), |
| 1431 |
&(sbcontext.num_deny_prefixes)); |
| 1432 |
|
| 1433 |
if(NULL != cached_env_vars[0]) |
| 1434 |
free(cached_env_vars[0]); |
| 1435 |
|
| 1436 |
if(NULL != deny) { |
| 1437 |
init_env_entries(&(sbcontext.deny_prefixes), |
| 1438 |
&(sbcontext.num_deny_prefixes), "SANDBOX_DENY", deny, 1); |
| 1439 |
cached_env_vars[0] = strdup(deny); |
| 1440 |
} else { |
| 1441 |
cached_env_vars[0] = NULL; |
| 1442 |
} |
| 1443 |
} |
| 1444 |
|
| 1445 |
if((read == NULL && cached_env_vars[1] != read) || cached_env_vars[1] == NULL || |
| 1446 |
strcmp(cached_env_vars[1], read) != 0) { |
| 1447 |
|
| 1448 |
clean_env_entries(&(sbcontext.read_prefixes), |
| 1449 |
&(sbcontext.num_read_prefixes)); |
| 1450 |
|
| 1451 |
if(NULL != cached_env_vars[1]) |
| 1452 |
free(cached_env_vars[1]); |
| 1453 |
|
| 1454 |
if(NULL != read) { |
| 1455 |
init_env_entries(&(sbcontext.read_prefixes), |
| 1456 |
&(sbcontext.num_read_prefixes), "SANDBOX_READ", read, 1); |
| 1457 |
cached_env_vars[1] = strdup(read); |
| 1458 |
} else { |
| 1459 |
cached_env_vars[1] = NULL; |
| 1460 |
} |
| 1461 |
} |
| 1462 |
|
| 1463 |
if((write == NULL && cached_env_vars[2] != write) || cached_env_vars[2] == NULL || |
| 1464 |
strcmp(cached_env_vars[2], write) != 0) { |
| 1465 |
|
| 1466 |
clean_env_entries(&(sbcontext.write_prefixes), |
| 1467 |
&(sbcontext.num_write_prefixes)); |
| 1468 |
|
| 1469 |
if(NULL != cached_env_vars[2]) |
| 1470 |
free(cached_env_vars[2]); |
| 1471 |
|
| 1472 |
if(NULL != write) { |
| 1473 |
init_env_entries(&(sbcontext.write_prefixes), |
| 1474 |
&(sbcontext.num_write_prefixes), "SANDBOX_WRITE", write, 1); |
| 1475 |
cached_env_vars[2] = strdup(write); |
| 1476 |
} else { |
| 1477 |
cached_env_vars[2] = NULL; |
| 1478 |
} |
| 1479 |
} |
| 1480 |
|
| 1481 |
if((predict == NULL && cached_env_vars[3] != predict) || cached_env_vars[3] == NULL || |
| 1482 |
strcmp(cached_env_vars[3], predict) != 0) { |
| 1483 |
|
| 1484 |
clean_env_entries(&(sbcontext.predict_prefixes), |
| 1485 |
&(sbcontext.num_predict_prefixes)); |
| 1486 |
|
| 1487 |
if(NULL != cached_env_vars[3]) |
| 1488 |
free(cached_env_vars[3]); |
| 1489 |
|
| 1490 |
if(NULL != predict) { |
| 1491 |
init_env_entries(&(sbcontext.predict_prefixes), |
| 1492 |
&(sbcontext.num_predict_prefixes), "SANDBOX_PREDICT", predict, 1); |
| 1493 |
cached_env_vars[3] = strdup(predict); |
| 1494 |
} else { |
| 1495 |
cached_env_vars[3] = NULL; |
| 1496 |
} |
| 1497 |
|
| 1498 |
} |
| 1499 |
|
| 1500 |
result = check_syscall(&sbcontext, func, file); |
| 1501 |
|
| 1502 |
errno = old_errno; |
| 1503 |
|
| 1504 |
if (0 == result) { |
| 1505 |
errno = EACCES; |
| 1506 |
} |
| 1507 |
|
| 1508 |
return result; |
| 1509 |
} |
| 1510 |
|
| 1511 |
static int before_syscall_access(const char *func, const char *file, int flags) |
| 1512 |
{ |
| 1513 |
if (flags & W_OK) { |
| 1514 |
return before_syscall("access_wr", file); |
| 1515 |
} else { |
| 1516 |
return before_syscall("access_rd", file); |
| 1517 |
} |
| 1518 |
} |
| 1519 |
|
| 1520 |
static int before_syscall_open_int(const char *func, const char *file, int flags) |
| 1521 |
{ |
| 1522 |
if ((flags & O_WRONLY) || (flags & O_RDWR)) { |
| 1523 |
return before_syscall("open_wr", file); |
| 1524 |
} else { |
| 1525 |
return before_syscall("open_rd", file); |
| 1526 |
} |
| 1527 |
} |
| 1528 |
|
| 1529 |
static int before_syscall_open_char(const char *func, const char *file, const char *mode) |
| 1530 |
{ |
| 1531 |
if (*mode == 'r' && ((strcmp(mode, "r") == 0) || |
| 1532 |
/* The strspn accept args are known non-writable modifiers */ |
| 1533 |
(strlen(++mode) == strspn(mode, "xbtmc")))) { |
| 1534 |
return before_syscall("open_rd", file); |
| 1535 |
} else { |
| 1536 |
return before_syscall("open_wr", file); |
| 1537 |
} |
| 1538 |
} |
| 1539 |
|
| 1540 |
#include "getcwd.c" |
| 1541 |
#include "canonicalize.c" |
| 1542 |
#include "sandbox_futils.c" |
| 1543 |
|
| 1544 |
// vim:noexpandtab noai:cindent ai |
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