// SPDX-License-Identifier: BSD-3-Clause /* * Simple Landlock sandbox manager able to execute a process restricted by * user-defined file system and network access control policies. * * Copyright © 2017-2020 Mickaël Salaün * Copyright © 2020 ANSSI */ #define _GNU_SOURCE #define __SANE_USERSPACE_TYPES__ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #if defined(__GLIBC__) #include #endif #ifndef landlock_create_ruleset static inline int landlock_create_ruleset(const struct landlock_ruleset_attr *const attr, const size_t size, const __u32 flags) { return syscall(__NR_landlock_create_ruleset, attr, size, flags); } #endif #ifndef landlock_add_rule static inline int landlock_add_rule(const int ruleset_fd, const enum landlock_rule_type rule_type, const void *const rule_attr, const __u32 flags) { return syscall(__NR_landlock_add_rule, ruleset_fd, rule_type, rule_attr, flags); } #endif #ifndef landlock_restrict_self static inline int landlock_restrict_self(const int ruleset_fd, const __u32 flags) { return syscall(__NR_landlock_restrict_self, ruleset_fd, flags); } #endif #define ENV_FS_RO_NAME "LL_FS_RO" #define ENV_FS_RW_NAME "LL_FS_RW" #define ENV_FS_QUIET_NAME "LL_FS_QUIET" #define ENV_TCP_BIND_NAME "LL_TCP_BIND" #define ENV_TCP_CONNECT_NAME "LL_TCP_CONNECT" #define ENV_NET_QUIET_NAME "LL_NET_QUIET" #define ENV_SCOPED_NAME "LL_SCOPED" #define ENV_QUIET_ACCESS_NAME "LL_QUIET_ACCESS" #define ENV_FORCE_LOG_NAME "LL_FORCE_LOG" #define ENV_UDP_BIND_NAME "LL_UDP_BIND" #define ENV_UDP_CONNECT_SEND_NAME "LL_UDP_CONNECT_SEND" #define ENV_DELIMITER ":" static int str2num(const char *numstr, __u64 *num_dst) { char *endptr = NULL; int err = 0; __u64 num; errno = 0; num = strtoull(numstr, &endptr, 10); if (errno != 0) err = errno; /* Was the string empty, or not entirely parsed successfully? */ else if ((*numstr == '\0') || (*endptr != '\0')) err = EINVAL; else *num_dst = num; return err; } static int parse_path(char *env_path, const char ***const path_list) { int i, num_paths = 0; if (env_path) { num_paths++; for (i = 0; env_path[i]; i++) { if (env_path[i] == ENV_DELIMITER[0]) num_paths++; } } *path_list = malloc(num_paths * sizeof(**path_list)); if (!*path_list) return -1; for (i = 0; i < num_paths; i++) (*path_list)[i] = strsep(&env_path, ENV_DELIMITER); return num_paths; } /* clang-format off */ #define ACCESS_FILE ( \ LANDLOCK_ACCESS_FS_EXECUTE | \ LANDLOCK_ACCESS_FS_WRITE_FILE | \ LANDLOCK_ACCESS_FS_READ_FILE | \ LANDLOCK_ACCESS_FS_TRUNCATE | \ LANDLOCK_ACCESS_FS_IOCTL_DEV | \ LANDLOCK_ACCESS_FS_RESOLVE_UNIX) /* clang-format on */ static int populate_ruleset_fs(const char *const env_var, const int ruleset_fd, const __u64 allowed_access, __u32 flags) { int num_paths, i, ret = 1; char *env_path_name; const char **path_list = NULL; struct landlock_path_beneath_attr path_beneath = { .parent_fd = -1, }; env_path_name = getenv(env_var); if (!env_path_name) { /* Prevents users to forget a setting. */ fprintf(stderr, "Missing environment variable %s\n", env_var); return 1; } env_path_name = strdup(env_path_name); unsetenv(env_var); num_paths = parse_path(env_path_name, &path_list); if (num_paths < 0) { fprintf(stderr, "Failed to allocate memory\n"); goto out_free_name; } if (num_paths == 1 && path_list[0][0] == '\0') { /* * Allows to not use all possible restrictions (e.g. use * LL_FS_RO without LL_FS_RW). */ ret = 0; goto out_free_name; } for (i = 0; i < num_paths; i++) { struct stat statbuf; path_beneath.parent_fd = open(path_list[i], O_PATH | O_CLOEXEC); if (path_beneath.parent_fd < 0) { fprintf(stderr, "Failed to open \"%s\": %s\n", path_list[i], strerror(errno)); continue; } if (fstat(path_beneath.parent_fd, &statbuf)) { fprintf(stderr, "Failed to stat \"%s\": %s\n", path_list[i], strerror(errno)); close(path_beneath.parent_fd); goto out_free_name; } path_beneath.allowed_access = allowed_access; if (!S_ISDIR(statbuf.st_mode)) path_beneath.allowed_access &= ACCESS_FILE; if (landlock_add_rule(ruleset_fd, LANDLOCK_RULE_PATH_BENEATH, &path_beneath, flags)) { fprintf(stderr, "Failed to update the ruleset with \"%s\": %s\n", path_list[i], strerror(errno)); close(path_beneath.parent_fd); goto out_free_name; } close(path_beneath.parent_fd); } ret = 0; out_free_name: free(path_list); free(env_path_name); return ret; } static int populate_ruleset_net(const char *const env_var, const int ruleset_fd, const __u64 allowed_access, __u32 flags) { int ret = 1; char *env_port_name, *env_port_name_next, *strport; struct landlock_net_port_attr net_port = { .allowed_access = allowed_access, }; env_port_name = getenv(env_var); if (!env_port_name) return 0; env_port_name = strdup(env_port_name); unsetenv(env_var); env_port_name_next = env_port_name; while ((strport = strsep(&env_port_name_next, ENV_DELIMITER))) { __u64 port; if (strcmp(strport, "") == 0) continue; if (str2num(strport, &port)) { fprintf(stderr, "Failed to parse port at \"%s\"\n", strport); goto out_free_name; } net_port.port = port; if (landlock_add_rule(ruleset_fd, LANDLOCK_RULE_NET_PORT, &net_port, flags)) { fprintf(stderr, "Failed to update the ruleset with port \"%llu\": %s\n", net_port.port, strerror(errno)); goto out_free_name; } } ret = 0; out_free_name: free(env_port_name); return ret; } /* Returns true on error, false otherwise. */ static bool check_ruleset_scope(const char *const env_var, struct landlock_ruleset_attr *ruleset_attr) { char *env_type_scope, *env_type_scope_next, *ipc_scoping_name; bool error = false; bool abstract_scoping = false; bool signal_scoping = false; /* Scoping is not supported by Landlock ABI */ if (!(ruleset_attr->scoped & (LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL))) goto out_unset; env_type_scope = getenv(env_var); /* Scoping is not supported by the user */ if (!env_type_scope || strcmp("", env_type_scope) == 0) goto out_unset; env_type_scope = strdup(env_type_scope); env_type_scope_next = env_type_scope; while ((ipc_scoping_name = strsep(&env_type_scope_next, ENV_DELIMITER))) { if (strcmp("a", ipc_scoping_name) == 0 && !abstract_scoping) { abstract_scoping = true; } else if (strcmp("s", ipc_scoping_name) == 0 && !signal_scoping) { signal_scoping = true; } else { fprintf(stderr, "Unknown or duplicate scope \"%s\"\n", ipc_scoping_name); error = true; goto out_free_name; } } out_free_name: free(env_type_scope); out_unset: if (!abstract_scoping) ruleset_attr->scoped &= ~LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET; if (!signal_scoping) ruleset_attr->scoped &= ~LANDLOCK_SCOPE_SIGNAL; unsetenv(env_var); return error; } /* clang-format off */ #define ACCESS_FS_ROUGHLY_READ ( \ LANDLOCK_ACCESS_FS_EXECUTE | \ LANDLOCK_ACCESS_FS_READ_FILE | \ LANDLOCK_ACCESS_FS_READ_DIR) #define ACCESS_FS_ROUGHLY_WRITE ( \ LANDLOCK_ACCESS_FS_WRITE_FILE | \ LANDLOCK_ACCESS_FS_REMOVE_DIR | \ LANDLOCK_ACCESS_FS_REMOVE_FILE | \ LANDLOCK_ACCESS_FS_MAKE_CHAR | \ LANDLOCK_ACCESS_FS_MAKE_DIR | \ LANDLOCK_ACCESS_FS_MAKE_REG | \ LANDLOCK_ACCESS_FS_MAKE_SOCK | \ LANDLOCK_ACCESS_FS_MAKE_FIFO | \ LANDLOCK_ACCESS_FS_MAKE_BLOCK | \ LANDLOCK_ACCESS_FS_MAKE_SYM | \ LANDLOCK_ACCESS_FS_REFER | \ LANDLOCK_ACCESS_FS_TRUNCATE | \ LANDLOCK_ACCESS_FS_IOCTL_DEV | \ LANDLOCK_ACCESS_FS_RESOLVE_UNIX) /* clang-format on */ /* * Parses ENV_QUIET_ACCESS_NAME and sets the quiet_access_fs, quiet_access_net * and quiet_scoped masks of @ruleset_attr accordingly. */ static int add_quiet_access(const char *const env_var, struct landlock_ruleset_attr *const ruleset_attr) { char *env_quiet_access, *env_quiet_access_next, *str_access; env_quiet_access = getenv(env_var); if (!env_quiet_access) return 0; env_quiet_access = strdup(env_quiet_access); env_quiet_access_next = env_quiet_access; unsetenv(env_var); while ((str_access = strsep(&env_quiet_access_next, ENV_DELIMITER))) { if (strcmp(str_access, "") == 0) continue; else if (strcmp(str_access, "all") == 0) { ruleset_attr->quiet_access_fs = ruleset_attr->handled_access_fs; ruleset_attr->quiet_access_net = ruleset_attr->handled_access_net; ruleset_attr->quiet_scoped = ruleset_attr->scoped; } else if (strcmp(str_access, "read") == 0) ruleset_attr->quiet_access_fs |= ACCESS_FS_ROUGHLY_READ; else if (strcmp(str_access, "write") == 0) ruleset_attr->quiet_access_fs |= ACCESS_FS_ROUGHLY_WRITE; else if (strcmp(str_access, "tcp_bind") == 0) ruleset_attr->quiet_access_net |= LANDLOCK_ACCESS_NET_BIND_TCP; else if (strcmp(str_access, "tcp_connect") == 0) ruleset_attr->quiet_access_net |= LANDLOCK_ACCESS_NET_CONNECT_TCP; else if (strcmp(str_access, "udp_bind") == 0) ruleset_attr->quiet_access_net |= LANDLOCK_ACCESS_NET_BIND_UDP; else if (strcmp(str_access, "udp_connect") == 0) ruleset_attr->quiet_access_net |= LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP; else if (strcmp(str_access, "abstract_unix_socket") == 0) ruleset_attr->quiet_scoped |= LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET; else if (strcmp(str_access, "signal") == 0) ruleset_attr->quiet_scoped |= LANDLOCK_SCOPE_SIGNAL; else { fprintf(stderr, "Unknown quiet access \"%s\"\n", str_access); free(env_quiet_access); return -1; } } free(env_quiet_access); ruleset_attr->quiet_access_fs &= ruleset_attr->handled_access_fs; ruleset_attr->quiet_access_net &= ruleset_attr->handled_access_net; ruleset_attr->quiet_scoped &= ruleset_attr->scoped; return 0; } #define LANDLOCK_ABI_LAST 10 #define XSTR(s) #s #define STR(s) XSTR(s) /* clang-format off */ static const char help[] = "usage: " ENV_FS_RO_NAME "=\"...\" " ENV_FS_RW_NAME "=\"...\" " "[other environment variables] %1$s [args]...\n" "\n" "Execute the given command in a restricted environment.\n" "Multi-valued settings (lists of ports, paths, scopes) are colon-delimited.\n" "\n" "Mandatory settings:\n" "* " ENV_FS_RO_NAME ": paths allowed to be used in a read-only way\n" "* " ENV_FS_RW_NAME ": paths allowed to be used in a read-write way\n" "\n" "Optional settings (when not set, their associated access check " "is always allowed, which is different from an empty string which " "means an empty list):\n" "* " ENV_TCP_BIND_NAME ": ports allowed to bind (server)\n" "* " ENV_TCP_CONNECT_NAME ": ports allowed to connect (client)\n" "* " ENV_UDP_BIND_NAME ": local UDP ports allowed to bind (server: " "prepare to receive on port / client: set as source port)\n" "* " ENV_UDP_CONNECT_SEND_NAME ": remote UDP ports allowed to connect " "or send to (client: use as destination port / server: receive only from it)\n" "(caution: sending requires being able to bind to a local source port)\n" "* " ENV_SCOPED_NAME ": actions denied on the outside of the landlock domain\n" " - \"a\" to restrict opening abstract unix sockets\n" " - \"s\" to restrict sending signals\n" "\n" "A sandboxer should not log denied access requests to avoid spamming logs, " "but to test audit we can set " ENV_FORCE_LOG_NAME "=1\n" ENV_FS_QUIET_NAME " and " ENV_NET_QUIET_NAME ", both optional, can then be used " "to make access to some denied paths or network ports not trigger audit logging.\n" ENV_QUIET_ACCESS_NAME " can be used to specify which accesses should be quieted " "(required when " ENV_FS_QUIET_NAME " or " ENV_NET_QUIET_NAME " is set):\n" " - \"all\" to quiet all of the accesses below\n" " - \"read\" to quiet all file/dir read accesses\n" " - \"write\" to quiet all file/dir write accesses\n" " - \"tcp_bind\" to quiet tcp bind denials\n" " - \"tcp_connect\" to quiet tcp connect denials\n" " - \"udp_bind\" to quiet udp bind denials\n" " - \"udp_connect\" to quiet udp connect / send denials\n" " - \"abstract_unix_socket\" to quiet abstract unix socket denials\n" " - \"signal\" to quiet signal denials\n" "\n" "Example:\n" ENV_FS_RO_NAME "=\"${PATH}:/lib:/usr:/proc:/etc:/dev/urandom\" " ENV_FS_RW_NAME "=\"/dev/null:/dev/full:/dev/zero:/dev/pts:/tmp\" " ENV_TCP_BIND_NAME "=\"9418\" " ENV_TCP_CONNECT_NAME "=\"80:443\" " ENV_UDP_CONNECT_SEND_NAME "=\"53\" " ENV_SCOPED_NAME "=\"a:s\" " "%1$s bash -i\n" "\n" "This sandboxer can use Landlock features up to ABI version " STR(LANDLOCK_ABI_LAST) ".\n"; /* clang-format on */ int main(const int argc, char *const argv[], char *const *const envp) { const char *cmd_path; char *const *cmd_argv; int ruleset_fd, abi; char *env_port_name, *env_force_log; __u64 access_fs_ro = ACCESS_FS_ROUGHLY_READ, access_fs_rw = ACCESS_FS_ROUGHLY_READ | ACCESS_FS_ROUGHLY_WRITE; struct landlock_ruleset_attr ruleset_attr = { .handled_access_fs = access_fs_rw, .handled_access_net = LANDLOCK_ACCESS_NET_BIND_TCP | LANDLOCK_ACCESS_NET_CONNECT_TCP | LANDLOCK_ACCESS_NET_BIND_UDP | LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP, .scoped = LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL, .quiet_access_fs = 0, .quiet_access_net = 0, .quiet_scoped = 0, }; bool quiet_supported = true; int supported_restrict_flags = LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON; int set_restrict_flags = 0; if (argc < 2) { fprintf(stderr, help, argv[0]); return 1; } abi = landlock_create_ruleset(NULL, 0, LANDLOCK_CREATE_RULESET_VERSION); if (abi < 0) { const int err = errno; perror("Failed to check Landlock compatibility"); switch (err) { case ENOSYS: fprintf(stderr, "Hint: Landlock is not supported by the current kernel. " "To support it, build the kernel with " "CONFIG_SECURITY_LANDLOCK=y and prepend " "\"landlock,\" to the content of CONFIG_LSM.\n"); break; case EOPNOTSUPP: fprintf(stderr, "Hint: Landlock is currently disabled. " "It can be enabled in the kernel configuration by " "prepending \"landlock,\" to the content of CONFIG_LSM, " "or at boot time by setting the same content to the " "\"lsm\" kernel parameter.\n"); break; } return 1; } /* Best-effort security. */ switch (abi) { case 1: /* * Removes LANDLOCK_ACCESS_FS_REFER for ABI < 2 * * Note: The "refer" operations (file renaming and linking * across different directories) are always forbidden when using * Landlock with ABI 1. * * If only ABI 1 is available, this sandboxer knowingly forbids * refer operations. * * If a program *needs* to do refer operations after enabling * Landlock, it can not use Landlock at ABI level 1. To be * compatible with different kernel versions, such programs * should then fall back to not restrict themselves at all if * the running kernel only supports ABI 1. */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_REFER; __attribute__((fallthrough)); case 2: /* Removes LANDLOCK_ACCESS_FS_TRUNCATE for ABI < 3 */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_TRUNCATE; __attribute__((fallthrough)); case 3: /* Removes network support for ABI < 4 */ ruleset_attr.handled_access_net &= ~(LANDLOCK_ACCESS_NET_BIND_TCP | LANDLOCK_ACCESS_NET_CONNECT_TCP); __attribute__((fallthrough)); case 4: /* Removes LANDLOCK_ACCESS_FS_IOCTL_DEV for ABI < 5 */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_IOCTL_DEV; __attribute__((fallthrough)); case 5: /* Removes LANDLOCK_SCOPE_* for ABI < 6 */ ruleset_attr.scoped &= ~(LANDLOCK_SCOPE_ABSTRACT_UNIX_SOCKET | LANDLOCK_SCOPE_SIGNAL); __attribute__((fallthrough)); case 6: /* Removes LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON for ABI < 7 */ supported_restrict_flags &= ~LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON; __attribute__((fallthrough)); case 7: case 8: /* Removes LANDLOCK_ACCESS_FS_RESOLVE_UNIX for ABI < 9 */ ruleset_attr.handled_access_fs &= ~LANDLOCK_ACCESS_FS_RESOLVE_UNIX; __attribute__((fallthrough)); case 9: /* Removes UDP support for ABI < 10 */ ruleset_attr.handled_access_net &= ~(LANDLOCK_ACCESS_NET_BIND_UDP | LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP); /* Removes quiet flags for ABI < 10 later on. */ quiet_supported = false; /* Must be printed for any ABI < LANDLOCK_ABI_LAST. */ fprintf(stderr, "Hint: You should update the running kernel " "to leverage Landlock features " "provided by ABI version %d (instead of %d).\n", LANDLOCK_ABI_LAST, abi); __attribute__((fallthrough)); case LANDLOCK_ABI_LAST: break; default: fprintf(stderr, "Hint: You should update this sandboxer " "to leverage Landlock features " "provided by ABI version %d (instead of %d).\n", abi, LANDLOCK_ABI_LAST); } access_fs_ro &= ruleset_attr.handled_access_fs; access_fs_rw &= ruleset_attr.handled_access_fs; /* Removes bind access attribute if not supported by a user. */ env_port_name = getenv(ENV_TCP_BIND_NAME); if (!env_port_name) { ruleset_attr.handled_access_net &= ~LANDLOCK_ACCESS_NET_BIND_TCP; } /* Removes connect access attribute if not supported by a user. */ env_port_name = getenv(ENV_TCP_CONNECT_NAME); if (!env_port_name) { ruleset_attr.handled_access_net &= ~LANDLOCK_ACCESS_NET_CONNECT_TCP; } /* Removes UDP bind access control if not supported by a user. */ env_port_name = getenv(ENV_UDP_BIND_NAME); if (!env_port_name) { ruleset_attr.handled_access_net &= ~LANDLOCK_ACCESS_NET_BIND_UDP; } /* Removes UDP connect/send access control if not supported by a user. */ env_port_name = getenv(ENV_UDP_CONNECT_SEND_NAME); if (!env_port_name) { ruleset_attr.handled_access_net &= ~LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP; } if (check_ruleset_scope(ENV_SCOPED_NAME, &ruleset_attr)) return 1; /* Enables optional logs. */ env_force_log = getenv(ENV_FORCE_LOG_NAME); if (env_force_log) { if (strcmp(env_force_log, "1") != 0) { fprintf(stderr, "Unknown value for " ENV_FORCE_LOG_NAME " (only \"1\" is handled)\n"); return 1; } if (!(supported_restrict_flags & LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON)) { fprintf(stderr, "Audit logs not supported by current kernel\n"); return 1; } set_restrict_flags |= LANDLOCK_RESTRICT_SELF_LOG_NEW_EXEC_ON; unsetenv(ENV_FORCE_LOG_NAME); } /* Set the quiet access masks. */ if (quiet_supported) { if ((getenv(ENV_FS_QUIET_NAME) || getenv(ENV_NET_QUIET_NAME)) && !getenv(ENV_QUIET_ACCESS_NAME)) { fprintf(stderr, "%s must be set (e.g. to \"all\") when %s or %s is used\n", ENV_QUIET_ACCESS_NAME, ENV_FS_QUIET_NAME, ENV_NET_QUIET_NAME); return 1; } if (add_quiet_access(ENV_QUIET_ACCESS_NAME, &ruleset_attr)) return 1; } else if (getenv(ENV_FS_QUIET_NAME) || getenv(ENV_NET_QUIET_NAME) || getenv(ENV_QUIET_ACCESS_NAME)) { fprintf(stderr, "Quiet flags not supported by current kernel\n"); return 1; } ruleset_fd = landlock_create_ruleset(&ruleset_attr, sizeof(ruleset_attr), 0); if (ruleset_fd < 0) { perror("Failed to create a ruleset"); return 1; } if (populate_ruleset_fs(ENV_FS_RO_NAME, ruleset_fd, access_fs_ro, 0)) goto err_close_ruleset; if (populate_ruleset_fs(ENV_FS_RW_NAME, ruleset_fd, access_fs_rw, 0)) goto err_close_ruleset; /* Don't require this env to be present. */ if (quiet_supported && getenv(ENV_FS_QUIET_NAME)) { if (populate_ruleset_fs(ENV_FS_QUIET_NAME, ruleset_fd, 0, LANDLOCK_ADD_RULE_QUIET)) goto err_close_ruleset; } if (populate_ruleset_net(ENV_TCP_BIND_NAME, ruleset_fd, LANDLOCK_ACCESS_NET_BIND_TCP, 0)) { goto err_close_ruleset; } if (populate_ruleset_net(ENV_TCP_CONNECT_NAME, ruleset_fd, LANDLOCK_ACCESS_NET_CONNECT_TCP, 0)) { goto err_close_ruleset; } if (populate_ruleset_net(ENV_UDP_BIND_NAME, ruleset_fd, LANDLOCK_ACCESS_NET_BIND_UDP, 0)) { goto err_close_ruleset; } if (populate_ruleset_net(ENV_UDP_CONNECT_SEND_NAME, ruleset_fd, LANDLOCK_ACCESS_NET_CONNECT_SEND_UDP, 0)) { goto err_close_ruleset; } if (quiet_supported) { if (populate_ruleset_net(ENV_NET_QUIET_NAME, ruleset_fd, 0, LANDLOCK_ADD_RULE_QUIET)) { goto err_close_ruleset; } } if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)) { perror("Failed to restrict privileges"); goto err_close_ruleset; } if (landlock_restrict_self(ruleset_fd, set_restrict_flags)) { perror("Failed to enforce ruleset"); goto err_close_ruleset; } close(ruleset_fd); cmd_path = argv[1]; cmd_argv = argv + 1; fprintf(stderr, "Executing the sandboxed command...\n"); execvpe(cmd_path, cmd_argv, envp); fprintf(stderr, "Failed to execute \"%s\": %s\n", cmd_path, strerror(errno)); fprintf(stderr, "Hint: access to the binary, the interpreter or " "shared libraries may be denied.\n"); return 1; err_close_ruleset: close(ruleset_fd); return 1; }