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/*
* Copyright (C) 2014-2017 Firejail Authors
*
* This file is part of firejail project
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "firejail.h"
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
static char *paths[] = {
"/usr/local/bin",
"/usr/bin",
"/bin",
"/usr/games",
"/usr/local/games",
"/usr/local/sbin",
"/usr/sbin",
"/sbin",
NULL
};
// return 1 if found, 0 if not found
static char *check_dir_or_file(const char *name) {
assert(name);
struct stat s;
char *fname = NULL;
int i = 0;
while (paths[i]) {
// private-bin-no-local can be disabled in /etc/firejail/firejail.config
if (checkcfg(CFG_PRIVATE_BIN_NO_LOCAL) && strstr(paths[i], "local/")) {
i++;
continue;
}
// check file
if (asprintf(&fname, "%s/%s", paths[i], name) == -1)
errExit("asprintf");
if (arg_debug)
printf("Checking %s/%s\n", paths[i], name);
if (stat(fname, &s) == 0 && !S_ISDIR(s.st_mode)) { // do not allow directories
// check symlink to firejail executable in /usr/local/bin
if (strcmp(paths[i], "/usr/local/bin") == 0 && is_link(fname)) {
/* coverity[toctou] */
char *actual_path = realpath(fname, NULL);
if (actual_path) {
char *ptr = strstr(actual_path, "/firejail");
if (ptr && strlen(ptr) == strlen("/firejail")) {
if (arg_debug)
printf("firejail exec symlink detected\n");
free(actual_path);
free(fname);
fname = NULL;
i++;
continue;
}
free(actual_path);
}
}
break; // file found
}
free(fname);
fname = NULL;
i++;
}
if (!fname) {
if (arg_debug)
fwarning("file %s not found\n", name);
return NULL;
}
free(fname);
return paths[i];
}
// return 1 if the file is in paths[]
static int valid_full_path_file(const char *name) {
assert(name);
char *full_name = realpath(name, NULL);
if (!full_name)
goto errexit;
char *fname = strrchr(full_name, '/');
if (!fname)
goto errexit;
if (++fname == '\0')
goto errexit;
int i = 0;
int found = 0;
while (paths[i]) {
// private-bin-no-local can be disabled in /etc/firejail/firejail.config
if (checkcfg(CFG_PRIVATE_BIN_NO_LOCAL) && strstr(paths[i], "local/")) {
i++;
continue;
}
// check file
char *full_name2;
if (asprintf(&full_name2, "%s/%s", paths[i], fname) == -1)
errExit("asprintf");
if (strcmp(full_name, full_name2) == 0) {
free(full_name2);
found = 1;
break;
}
free(full_name2);
i++;
}
if (!found)
goto errexit;
free(full_name);
return 1;
errexit:
if (arg_debug)
fwarning("file %s not found\n", name);
if (full_name)
free(full_name);
return 0;
}
static void duplicate(char *fname, FILE *fplist) {
if (*fname == '~' || strstr(fname, "..")) {
fprintf(stderr, "Error: \"%s\" is an invalid filename\n", fname);
exit(1);
}
invalid_filename(fname);
char *full_path;
if (*fname == '/') {
// If the absolute filename is indicated, directly use it. This
// is required for the following three cases:
// - if user's $PATH order is not the same as the above
// paths[] variable order
// - if for example /usr/bin/which is a symlink to /bin/which,
// because in this case the result is a symlink pointing to
// itself due to the file name being the same.
if (!valid_full_path_file(fname))
return;
full_path = strdup(fname);
if (!full_path)
errExit("strdup");
}
else {
// Find the standard directory (by looping through paths[])
// where the filename fname is located
char *path = check_dir_or_file(fname);
if (!path)
return;
if (asprintf(&full_path, "%s/%s", path, fname) == -1)
errExit("asprintf");
}
if (fplist)
fprintf(fplist, "%s\n", full_path);
// copy the file
if (checkcfg(CFG_FOLLOW_SYMLINK_PRIVATE_BIN))
sbox_run(SBOX_ROOT| SBOX_SECCOMP, 4, PATH_FCOPY, "--follow-link", full_path, RUN_BIN_DIR);
else
sbox_run(SBOX_ROOT| SBOX_SECCOMP, 3, PATH_FCOPY, full_path, RUN_BIN_DIR);
fs_logger2("clone", fname);
free(full_path);
}
void fs_private_bin_list(void) {
char *private_list = cfg.bin_private_keep;
assert(private_list);
// create /run/firejail/mnt/bin directory
mkdir_attr(RUN_BIN_DIR, 0755, 0, 0);
if (arg_debug)
printf("Copying files in the new bin directory\n");
// copy the list of files in the new home directory
char *dlist = strdup(private_list);
if (!dlist)
errExit("strdup");
// save a list of private-bin files in order to bring in private-libs later
FILE *fplist = NULL;
if (arg_private_lib) {
fplist = fopen(RUN_LIB_BIN, "w");
if (!fplist)
errExit("fopen");
}
char *ptr = strtok(dlist, ",");
duplicate(ptr, fplist);
while ((ptr = strtok(NULL, ",")) != NULL)
duplicate(ptr, fplist);
free(dlist);
fs_logger_print();
if (fplist)
fclose(fplist);
// mount-bind
int i = 0;
while (paths[i]) {
struct stat s;
if (stat(paths[i], &s) == 0) {
if (arg_debug)
printf("Mount-bind %s on top of %s\n", RUN_BIN_DIR, paths[i]);
if (mount(RUN_BIN_DIR, paths[i], NULL, MS_BIND|MS_REC, NULL) < 0)
errExit("mount bind");
fs_logger2("tmpfs", paths[i]);
fs_logger2("mount", paths[i]);
}
i++;
}
}
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