diff options
Diffstat (limited to 'src/core')
| -rw-r--r-- | src/core/dbus-execute.c | 23 | ||||
| -rw-r--r-- | src/core/execute.c | 100 | ||||
| -rw-r--r-- | src/core/execute.h | 4 | ||||
| -rw-r--r-- | src/core/load-fragment-gperf.gperf.m4 | 3 | ||||
| -rw-r--r-- | src/core/load-fragment.c | 29 | ||||
| -rw-r--r-- | src/core/load-fragment.h | 2 | ||||
| -rw-r--r-- | src/core/main.c | 10 | ||||
| -rw-r--r-- | src/core/unit.c | 2 |
8 files changed, 128 insertions, 45 deletions
diff --git a/src/core/dbus-execute.c b/src/core/dbus-execute.c index 1f736b2686..c2238c8c43 100644 --- a/src/core/dbus-execute.c +++ b/src/core/dbus-execute.c @@ -293,9 +293,25 @@ static int property_get_capability_bounding_set( assert(reply); assert(c); - /* We store this negated internally, to match the kernel, but - * we expose it normalized. */ - return sd_bus_message_append(reply, "t", ~c->capability_bounding_set_drop); + return sd_bus_message_append(reply, "t", c->capability_bounding_set); +} + +static int property_get_ambient_capabilities( + 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, "t", c->capability_ambient_set); } static int property_get_capabilities( @@ -689,6 +705,7 @@ const sd_bus_vtable bus_exec_vtable[] = { SD_BUS_PROPERTY("Capabilities", "s", property_get_capabilities, 0, SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("SecureBits", "i", bus_property_get_int, offsetof(ExecContext, secure_bits), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("CapabilityBoundingSet", "t", property_get_capability_bounding_set, 0, SD_BUS_VTABLE_PROPERTY_CONST), + SD_BUS_PROPERTY("AmbientCapabilities", "t", property_get_ambient_capabilities, 0, SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("User", "s", NULL, offsetof(ExecContext, user), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("Group", "s", NULL, offsetof(ExecContext, group), SD_BUS_VTABLE_PROPERTY_CONST), SD_BUS_PROPERTY("SupplementaryGroups", "as", NULL, offsetof(ExecContext, supplementary_groups), SD_BUS_VTABLE_PROPERTY_CONST), diff --git a/src/core/execute.c b/src/core/execute.c index 9b76861919..ac91568b63 100644 --- a/src/core/execute.c +++ b/src/core/execute.c @@ -737,12 +737,7 @@ static int enforce_user(const ExecContext *context, uid_t uid) { /* Sets (but doesn't lookup) the uid and make sure we keep the * capabilities while doing so. */ - if (context->capabilities) { - _cleanup_cap_free_ cap_t d = NULL; - static const cap_value_t bits[] = { - CAP_SETUID, /* Necessary so that we can run setresuid() below */ - CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */ - }; + if (context->capabilities || context->capability_ambient_set != 0) { /* First step: If we need to keep capabilities but * drop privileges we need to make sure we keep our @@ -758,16 +753,24 @@ static int enforce_user(const ExecContext *context, uid_t uid) { /* Second step: set the capabilities. This will reduce * the capabilities to the minimum we need. */ - d = cap_dup(context->capabilities); - if (!d) - return -errno; + if (context->capabilities) { + _cleanup_cap_free_ cap_t d = NULL; + static const cap_value_t bits[] = { + CAP_SETUID, /* Necessary so that we can run setresuid() below */ + CAP_SETPCAP /* Necessary so that we can set PR_SET_SECUREBITS later on */ + }; - if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 || - cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) - return -errno; + d = cap_dup(context->capabilities); + if (!d) + return -errno; - if (cap_set_proc(d) < 0) - return -errno; + if (cap_set_flag(d, CAP_EFFECTIVE, ELEMENTSOF(bits), bits, CAP_SET) < 0 || + cap_set_flag(d, CAP_PERMITTED, ELEMENTSOF(bits), bits, CAP_SET) < 0) + return -errno; + + if (cap_set_proc(d) < 0) + return -errno; + } } /* Third step: actually set the uids */ @@ -1856,6 +1859,8 @@ static int exec_child( if (params->apply_permissions) { + int secure_bits = context->secure_bits; + for (i = 0; i < _RLIMIT_MAX; i++) { if (!context->rlimit[i]) continue; @@ -1866,28 +1871,71 @@ static int exec_child( } } - if (context->capability_bounding_set_drop) { - r = capability_bounding_set_drop(context->capability_bounding_set_drop, false); + if (!cap_test_all(context->capability_bounding_set)) { + r = capability_bounding_set_drop(context->capability_bounding_set, false); if (r < 0) { *exit_status = EXIT_CAPABILITIES; return r; } } + /* This is done before enforce_user, but ambient set + * does not survive over setresuid() if keep_caps is not set. */ + if (context->capability_ambient_set != 0) { + r = capability_ambient_set_apply(context->capability_ambient_set, true); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return r; + } + + if (context->capabilities) { + + /* The capabilities in ambient set need to be also in the inherited + * set. If they aren't, trying to get them will fail. Add the ambient + * set inherited capabilities to the capability set in the context. + * This is needed because if capabilities are set (using "Capabilities=" + * keyword), they will override whatever we set now. */ + + r = capability_update_inherited_set(context->capabilities, context->capability_ambient_set); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return r; + } + } + } + if (context->user) { r = enforce_user(context, uid); if (r < 0) { *exit_status = EXIT_USER; return r; } + if (context->capability_ambient_set != 0) { + + /* Fix the ambient capabilities after user change. */ + r = capability_ambient_set_apply(context->capability_ambient_set, false); + if (r < 0) { + *exit_status = EXIT_CAPABILITIES; + return r; + } + + /* If we were asked to change user and ambient capabilities + * were requested, we had to add keep-caps to the securebits + * so that we would maintain the inherited capability set + * through the setresuid(). Make sure that the bit is added + * also to the context secure_bits so that we don't try to + * drop the bit away next. */ + + secure_bits |= 1<<SECURE_KEEP_CAPS; + } } /* PR_GET_SECUREBITS is not privileged, while * PR_SET_SECUREBITS is. So to suppress * potential EPERMs we'll try not to call * PR_SET_SECUREBITS unless necessary. */ - if (prctl(PR_GET_SECUREBITS) != context->secure_bits) - if (prctl(PR_SET_SECUREBITS, context->secure_bits) < 0) { + if (prctl(PR_GET_SECUREBITS) != secure_bits) + if (prctl(PR_SET_SECUREBITS, secure_bits) < 0) { *exit_status = EXIT_SECUREBITS; return -errno; } @@ -2114,6 +2162,7 @@ void exec_context_init(ExecContext *c) { c->timer_slack_nsec = NSEC_INFINITY; c->personality = PERSONALITY_INVALID; c->runtime_directory_mode = 0755; + c->capability_bounding_set = CAP_ALL; } void exec_context_done(ExecContext *c) { @@ -2517,12 +2566,23 @@ void exec_context_dump(ExecContext *c, FILE* f, const char *prefix) { (c->secure_bits & 1<<SECURE_NOROOT) ? " noroot" : "", (c->secure_bits & 1<<SECURE_NOROOT_LOCKED) ? "noroot-locked" : ""); - if (c->capability_bounding_set_drop) { + if (c->capability_bounding_set != CAP_ALL) { unsigned long l; fprintf(f, "%sCapabilityBoundingSet:", prefix); for (l = 0; l <= cap_last_cap(); l++) - if (!(c->capability_bounding_set_drop & ((uint64_t) 1ULL << (uint64_t) l))) + if (c->capability_bounding_set & (UINT64_C(1) << l)) + fprintf(f, " %s", strna(capability_to_name(l))); + + fputs("\n", f); + } + + if (c->capability_ambient_set != 0) { + unsigned long l; + fprintf(f, "%sAmbientCapabilities:", prefix); + + for (l = 0; l <= cap_last_cap(); l++) + if (c->capability_ambient_set & (UINT64_C(1) << l)) fprintf(f, " %s", strna(capability_to_name(l))); fputs("\n", f); diff --git a/src/core/execute.h b/src/core/execute.h index be5be9f531..8649620830 100644 --- a/src/core/execute.h +++ b/src/core/execute.h @@ -155,7 +155,9 @@ struct ExecContext { char **read_write_dirs, **read_only_dirs, **inaccessible_dirs; unsigned long mount_flags; - uint64_t capability_bounding_set_drop; + uint64_t capability_bounding_set; + + uint64_t capability_ambient_set; cap_t capabilities; int secure_bits; diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4 index 0408b9a829..29ab1b6b9e 100644 --- a/src/core/load-fragment-gperf.gperf.m4 +++ b/src/core/load-fragment-gperf.gperf.m4 @@ -47,7 +47,8 @@ $1.SyslogLevel, config_parse_log_level, 0, $1.SyslogLevelPrefix, config_parse_bool, 0, offsetof($1, exec_context.syslog_level_prefix) $1.Capabilities, config_parse_exec_capabilities, 0, offsetof($1, exec_context) $1.SecureBits, config_parse_exec_secure_bits, 0, offsetof($1, exec_context) -$1.CapabilityBoundingSet, config_parse_bounding_set, 0, offsetof($1, exec_context.capability_bounding_set_drop) +$1.CapabilityBoundingSet, config_parse_capability_set, 0, offsetof($1, exec_context.capability_bounding_set) +$1.AmbientCapabilities, config_parse_capability_set, 0, offsetof($1, exec_context.capability_ambient_set) $1.TimerSlackNSec, config_parse_nsec, 0, offsetof($1, exec_context.timer_slack_nsec) $1.NoNewPrivileges, config_parse_no_new_privileges, 0, offsetof($1, exec_context) m4_ifdef(`HAVE_SECCOMP', diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c index cb553e1252..d3880b4e3c 100644 --- a/src/core/load-fragment.c +++ b/src/core/load-fragment.c @@ -38,6 +38,7 @@ #include "bus-internal.h" #include "bus-util.h" #include "cap-list.h" +#include "capability-util.h" #include "cgroup.h" #include "conf-parser.h" #include "cpu-set-util.h" @@ -1024,7 +1025,7 @@ int config_parse_exec_secure_bits(const char *unit, return 0; } -int config_parse_bounding_set( +int config_parse_capability_set( const char *unit, const char *filename, unsigned line, @@ -1036,8 +1037,8 @@ int config_parse_bounding_set( void *data, void *userdata) { - uint64_t *capability_bounding_set_drop = data; - uint64_t capability_bounding_set, sum = 0; + uint64_t *capability_set = data; + uint64_t sum = 0, initial = 0; bool invert = false; const char *p; @@ -1051,10 +1052,9 @@ int config_parse_bounding_set( rvalue++; } - /* Note that we store this inverted internally, since the - * kernel wants it like this. But we actually expose it - * non-inverted everywhere to have a fully normalized - * interface. */ + if (strcmp(lvalue, "CapabilityBoundingSet") == 0) + initial = CAP_ALL; /* initialized to all bits on */ + /* else "AmbientCapabilities" initialized to all bits off */ p = rvalue; for (;;) { @@ -1073,18 +1073,21 @@ int config_parse_bounding_set( cap = capability_from_name(word); if (cap < 0) { - log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse capability in bounding set, ignoring: %s", word); + log_syntax(unit, LOG_ERR, filename, line, 0, "Failed to parse capability in bounding/ambient set, ignoring: %s", word); continue; } sum |= ((uint64_t) UINT64_C(1)) << (uint64_t) cap; } - capability_bounding_set = invert ? ~sum : sum; - if (*capability_bounding_set_drop != 0 && capability_bounding_set != 0) - *capability_bounding_set_drop = ~(~*capability_bounding_set_drop | capability_bounding_set); + sum = invert ? ~sum : sum; + + if (sum == 0 || *capability_set == initial) + /* "" or uninitialized data -> replace */ + *capability_set = sum; else - *capability_bounding_set_drop = ~capability_bounding_set; + /* previous data -> merge */ + *capability_set |= sum; return 0; } @@ -4002,7 +4005,7 @@ void unit_dump_config_items(FILE *f) { { config_parse_log_level, "LEVEL" }, { config_parse_exec_capabilities, "CAPABILITIES" }, { config_parse_exec_secure_bits, "SECUREBITS" }, - { config_parse_bounding_set, "BOUNDINGSET" }, + { config_parse_capability_set, "BOUNDINGSET" }, { config_parse_limit, "LIMIT" }, { config_parse_unit_deps, "UNIT [...]" }, { config_parse_exec, "PATH [ARGUMENT [...]]" }, diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h index a451fc164a..f0027a6b43 100644 --- a/src/core/load-fragment.h +++ b/src/core/load-fragment.h @@ -56,7 +56,7 @@ int config_parse_exec_cpu_sched_prio(const char *unit, const char *filename, uns int config_parse_exec_cpu_affinity(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_capabilities(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_secure_bits(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_bounding_set(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_capability_set(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_limit(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_bytes_limit(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_sec_limit(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/core/main.c b/src/core/main.c index f9de54028e..7a428fcccf 100644 --- a/src/core/main.c +++ b/src/core/main.c @@ -117,7 +117,7 @@ static usec_t arg_runtime_watchdog = 0; static usec_t arg_shutdown_watchdog = 10 * USEC_PER_MINUTE; static char **arg_default_environment = NULL; static struct rlimit *arg_default_rlimit[_RLIMIT_MAX] = {}; -static uint64_t arg_capability_bounding_set_drop = 0; +static uint64_t arg_capability_bounding_set = CAP_ALL; static nsec_t arg_timer_slack_nsec = NSEC_INFINITY; static usec_t arg_default_timer_accuracy_usec = 1 * USEC_PER_MINUTE; static Set* arg_syscall_archs = NULL; @@ -644,7 +644,7 @@ static int parse_config_file(void) { { "Manager", "JoinControllers", config_parse_join_controllers, 0, &arg_join_controllers }, { "Manager", "RuntimeWatchdogSec", config_parse_sec, 0, &arg_runtime_watchdog }, { "Manager", "ShutdownWatchdogSec", config_parse_sec, 0, &arg_shutdown_watchdog }, - { "Manager", "CapabilityBoundingSet", config_parse_bounding_set, 0, &arg_capability_bounding_set_drop }, + { "Manager", "CapabilityBoundingSet", config_parse_capability_set, 0, &arg_capability_bounding_set }, #ifdef HAVE_SECCOMP { "Manager", "SystemCallArchitectures", config_parse_syscall_archs, 0, &arg_syscall_archs }, #endif @@ -1631,14 +1631,14 @@ int main(int argc, char *argv[]) { if (prctl(PR_SET_TIMERSLACK, arg_timer_slack_nsec) < 0) log_error_errno(errno, "Failed to adjust timer slack: %m"); - if (arg_capability_bounding_set_drop) { - r = capability_bounding_set_drop_usermode(arg_capability_bounding_set_drop); + if (!cap_test_all(arg_capability_bounding_set)) { + r = capability_bounding_set_drop_usermode(arg_capability_bounding_set); if (r < 0) { log_emergency_errno(r, "Failed to drop capability bounding set of usermode helpers: %m"); error_message = "Failed to drop capability bounding set of usermode helpers"; goto finish; } - r = capability_bounding_set_drop(arg_capability_bounding_set_drop, true); + r = capability_bounding_set_drop(arg_capability_bounding_set, true); if (r < 0) { log_emergency_errno(r, "Failed to drop capability bounding set: %m"); error_message = "Failed to drop capability bounding set"; diff --git a/src/core/unit.c b/src/core/unit.c index b977ac7f0c..e1bc6c75cb 100644 --- a/src/core/unit.c +++ b/src/core/unit.c @@ -3231,7 +3231,7 @@ int unit_patch_contexts(Unit *u) { ec->no_new_privileges = true; if (ec->private_devices) - ec->capability_bounding_set_drop |= (uint64_t) 1ULL << (uint64_t) CAP_MKNOD; + ec->capability_bounding_set &= ~(UINT64_C(1) << CAP_MKNOD); } cc = unit_get_cgroup_context(u); |