From: WaLyong Cho Date: Mon, 24 Nov 2014 11:46:20 +0000 (+0900) Subject: smack: introduce new SmackProcessLabel option X-Git-Tag: v218~380 X-Git-Url: http://git.ipfire.org/?p=thirdparty%2Fsystemd.git;a=commitdiff_plain;h=2ca620c4ed28c01f285d869d0b22f22a360957da smack: introduce new SmackProcessLabel option In service file, if the file has some of special SMACK label in ExecStart= and systemd has no permission for the special SMACK label then permission error will occurred. To resolve this, systemd should be able to set its SMACK label to something accessible of ExecStart=. So introduce new SmackProcessLabel. If label is specified with SmackProcessLabel= then the child systemd will set its label to that. To successfully execute the ExecStart=, accessible label should be specified with SmackProcessLabel=. Additionally, by SMACK policy, if the file in ExecStart= has no SMACK64EXEC then the executed process will have given label by SmackProcessLabel=. But if the file has SMACK64EXEC then the SMACK64EXEC label will be overridden. [zj: reword man page] --- diff --git a/man/systemd.exec.xml b/man/systemd.exec.xml index e9af4abd6d5..0747d0e1f97 100644 --- a/man/systemd.exec.xml +++ b/man/systemd.exec.xml @@ -1137,6 +1137,35 @@ + + SmackProcessLabel= + + Takes a + security + label as argument. The process + executed by the unit will be started + under this label and SMACK will decide + whether the processes is allowed to + run or not based on it. The process + will continue to run under the label + specified here unless the executable + has its own + label, in + which case the process will transition + to run under that label. When not + specified, the label that systemd is + running under is used. This directive + is ignored if SMACK is + disabled. + + The value may be prefixed by + -, in which case + all errors will be ignored. An empty + value may be specified to unset + previous assignments. + + + IgnoreSIGPIPE= diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c index 9276da4cdc3..bbcd6106ad6 100644 --- a/src/core/dbus-execute.c +++ b/src/core/dbus-execute.c @@ -508,6 +508,24 @@ static int property_get_apparmor_profile( return sd_bus_message_append(reply, "(bs)", c->apparmor_profile_ignore, c->apparmor_profile); } +static int property_get_smack_process_label( + sd_bus *bus, + const char *path, + const char *interface, + const char *property, + sd_bus_message *reply, + void *userdata, + sd_bus_error *error) { + + ExecContext *c = userdata; + + assert(bus); + assert(reply); + assert(c); + + return sd_bus_message_append(reply, "(bs)", c->smack_process_label_ignore, c->smack_process_label); +} + static int property_get_personality( sd_bus *bus, const char *path, @@ -636,6 +654,7 @@ const sd_bus_vtable bus_exec_vtable[] = { SD_BUS_PROPERTY("UtmpIdentifier", "s", NULL, offsetof(ExecContext, utmp_id), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("SELinuxContext", "(bs)", property_get_selinux_context, 0, SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("AppArmorProfile", "(bs)", property_get_apparmor_profile, 0, SD_BUS_VTABLE_PROPERTY_CONST), + SD_BUS_PROPERTY("SmackProcessLabel", "(bs)", property_get_smack_process_label, 0, SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("IgnoreSIGPIPE", "b", bus_property_get_bool, offsetof(ExecContext, ignore_sigpipe), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("NoNewPrivileges", "b", bus_property_get_bool, offsetof(ExecContext, no_new_privileges), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("SystemCallFilter", "(bas)", property_get_syscall_filter, 0, SD_BUS_VTABLE_PROPERTY_CONST), diff --git a/src/core/execute.c b/src/core/execute.c index 5cfd4a1f975..e6c19993aef 100644 --- a/src/core/execute.c +++ b/src/core/execute.c @@ -83,6 +83,7 @@ #include "af-list.h" #include "mkdir.h" #include "apparmor-util.h" +#include "smack-util.h" #include "bus-kernel.h" #include "label.h" @@ -1618,6 +1619,16 @@ static int exec_child(ExecCommand *command, } } +#ifdef HAVE_SMACK + if (context->smack_process_label) { + err = mac_smack_apply_pid(0, context->smack_process_label); + if (err < 0) { + *error = EXIT_SMACK_PROCESS_LABEL; + return err; + } + } +#endif + if (context->user) { err = enforce_user(context, uid); if (err < 0) { diff --git a/src/core/execute.h b/src/core/execute.h index b16a24d0c6a..5ed750534d0 100644 --- a/src/core/execute.h +++ b/src/core/execute.h @@ -142,6 +142,9 @@ struct ExecContext { bool apparmor_profile_ignore; char *apparmor_profile; + bool smack_process_label_ignore; + char *smack_process_label; + char **read_write_dirs, **read_only_dirs, **inaccessible_dirs; unsigned long mount_flags; diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4 index 1d2debe70f2..a94b805b4b4 100644 --- a/src/core/load-fragment-gperf.gperf.m4 +++ b/src/core/load-fragment-gperf.gperf.m4 @@ -95,8 +95,11 @@ m4_ifdef(`HAVE_SELINUX', `$1.SELinuxContext, config_parse_exec_selinux_context, 0, offsetof($1, exec_context)', `$1.SELinuxContext, config_parse_warn_compat, 0, 0') m4_ifdef(`HAVE_APPARMOR', -`$1.AppArmorProfile, config_parse_exec_apparmor_profile,0, offsetof($1, exec_context)', -`$1.AppArmorProfile, config_parse_warn_compat, 0, 0')' +`$1.AppArmorProfile, config_parse_exec_apparmor_profile, 0, offsetof($1, exec_context)', +`$1.AppArmorProfile, config_parse_warn_compat, 0, 0') +m4_ifdef(`HAVE_SMACK', +`$1.SmackProcessLabel, config_parse_exec_smack_process_label, 0, offsetof($1, exec_context)', +`$1.SmackProcessLabel, config_parse_warn_compat, 0, 0')' )m4_dnl m4_define(`KILL_CONTEXT_CONFIG_ITEMS', `$1.SendSIGKILL, config_parse_bool, 0, offsetof($1, kill_context.send_sigkill) diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index 2ee16bdef9e..4309121649f 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -1313,6 +1313,56 @@ int config_parse_exec_apparmor_profile( return 0; } +int config_parse_exec_smack_process_label( + const char *unit, + const char *filename, + unsigned line, + const char *section, + unsigned section_line, + const char *lvalue, + int ltype, + const char *rvalue, + void *data, + void *userdata) { + + ExecContext *c = data; + Unit *u = userdata; + bool ignore; + char *k; + int r; + + assert(filename); + assert(lvalue); + assert(rvalue); + assert(data); + + if (isempty(rvalue)) { + free(c->smack_process_label); + c->smack_process_label = NULL; + c->smack_process_label_ignore = false; + return 0; + } + + if (rvalue[0] == '-') { + ignore = true; + rvalue++; + } else + ignore = false; + + r = unit_name_printf(u, rvalue, &k); + if (r < 0) { + log_syntax(unit, LOG_ERR, filename, line, -r, + "Failed to resolve specifiers, ignoring: %s", strerror(-r)); + return 0; + } + + free(c->smack_process_label); + c->smack_process_label = k; + c->smack_process_label_ignore = ignore; + + return 0; +} + int config_parse_timer(const char *unit, const char *filename, unsigned line, diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h index 65100c9bd7e..a799c9a6903 100644 --- a/src/core/load-fragment.h +++ b/src/core/load-fragment.h @@ -94,6 +94,7 @@ int config_parse_job_mode_isolate(const char *unit, const char *filename, unsign int config_parse_exec_selinux_context(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_personality(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_exec_apparmor_profile(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); +int config_parse_exec_smack_process_label(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_address_families(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_runtime_directory(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); int config_parse_set_status(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata); diff --git a/src/shared/exit-status.h b/src/shared/exit-status.h index f719580426b..1d774f25dca 100644 --- a/src/shared/exit-status.h +++ b/src/shared/exit-status.h @@ -78,6 +78,7 @@ typedef enum ExitStatus { EXIT_MAKE_STARTER, EXIT_CHOWN, EXIT_BUS_ENDPOINT, + EXIT_SMACK_PROCESS_LABEL, } ExitStatus; typedef enum ExitStatusLevel { diff --git a/src/shared/smack-util.c b/src/shared/smack-util.c index a8dccd1554f..b6c96435ce9 100644 --- a/src/shared/smack-util.c +++ b/src/shared/smack-util.c @@ -25,6 +25,7 @@ #include "util.h" #include "path-util.h" +#include "fileio.h" #include "smack-util.h" #define SMACK_FLOOR_LABEL "_" @@ -123,6 +124,25 @@ int mac_smack_apply_ip_in_fd(int fd, const char *label) { return r; } +int mac_smack_apply_pid(pid_t pid, const char *label) { + int r = 0; + const char *p; + + assert(label); + +#ifdef HAVE_SMACK + if (!mac_smack_use()) + return 0; + + p = procfs_file_alloca(pid, "attr/current"); + r = write_string_file(p, label); + if (r < 0) + return r; +#endif + + return r; +} + int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs) { int r = 0; diff --git a/src/shared/smack-util.h b/src/shared/smack-util.h index 68778da38b6..50f55b1f4bd 100644 --- a/src/shared/smack-util.h +++ b/src/shared/smack-util.h @@ -31,5 +31,6 @@ int mac_smack_fix(const char *path, bool ignore_enoent, bool ignore_erofs); int mac_smack_apply(const char *path, const char *label); int mac_smack_apply_fd(int fd, const char *label); +int mac_smack_apply_pid(pid_t pid, const char *label); int mac_smack_apply_ip_in_fd(int fd, const char *label); int mac_smack_apply_ip_out_fd(int fd, const char *label);