diff --git a/src/core/dbus-manager.c b/src/core/dbus-manager.c index 98762514389..0136d38833f 100644 --- a/src/core/dbus-manager.c +++ b/src/core/dbus-manager.c @@ -19,6 +19,7 @@ #include #include +#include #include #include "alloc-util.h" @@ -38,6 +39,7 @@ #include "fs-util.h" #include "install.h" #include "log.h" +#include "parse-util.h" #include "path-util.h" #include "selinux-access.h" #include "stat-util.h" @@ -48,6 +50,10 @@ #include "virt.h" #include "watchdog.h" +/* Require 16MiB free in /run/systemd for reloading/reexecing. After all we need to serialize our state there, and if + * we can't we'll fail badly. */ +#define RELOAD_DISK_SPACE_MIN (UINT64_C(16) * UINT64_C(1024) * UINT64_C(1024)) + static UnitFileFlags unit_file_bools_to_flags(bool runtime, bool force) { return (runtime ? UNIT_FILE_RUNTIME : 0) | (force ? UNIT_FILE_FORCE : 0); @@ -1312,6 +1318,40 @@ static int method_refuse_snapshot(sd_bus_message *message, void *userdata, sd_bu return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Support for snapshots has been removed."); } +static int verify_run_space(const char *message, sd_bus_error *error) { + struct statvfs svfs; + uint64_t available; + + if (statvfs("/run/systemd", &svfs) < 0) + return sd_bus_error_set_errnof(error, errno, "Failed to statvfs(/run/systemd): %m"); + + available = (uint64_t) svfs.f_bfree * (uint64_t) svfs.f_bsize; + + if (available < RELOAD_DISK_SPACE_MIN) { + char fb_available[FORMAT_BYTES_MAX], fb_need[FORMAT_BYTES_MAX]; + return sd_bus_error_setf(error, + BUS_ERROR_DISK_FULL, + "%s, not enough space available on /run/systemd. " + "Currently, %s are free, but a safety buffer of %s is enforced.", + message, + format_bytes(fb_available, sizeof(fb_available), available), + format_bytes(fb_need, sizeof(fb_need), RELOAD_DISK_SPACE_MIN)); + } + + return 0; +} + +int verify_run_space_and_log(const char *message) { + sd_bus_error error = SD_BUS_ERROR_NULL; + int r; + + r = verify_run_space(message, &error); + if (r < 0) + log_error_errno(r, "%s", bus_error_message(&error, r)); + + return r; +} + static int method_reload(sd_bus_message *message, void *userdata, sd_bus_error *error) { Manager *m = userdata; int r; @@ -1319,6 +1359,10 @@ static int method_reload(sd_bus_message *message, void *userdata, sd_bus_error * assert(message); assert(m); + r = verify_run_space("Refusing to reload", error); + if (r < 0) + return r; + r = mac_selinux_access_check(message, "reload", error); if (r < 0) return r; @@ -1351,6 +1395,10 @@ static int method_reexecute(sd_bus_message *message, void *userdata, sd_bus_erro assert(message); assert(m); + r = verify_run_space("Refusing to reexecute", error); + if (r < 0) + return r; + r = mac_selinux_access_check(message, "reload", error); if (r < 0) return r; @@ -1469,11 +1517,26 @@ static int method_switch_root(sd_bus_message *message, void *userdata, sd_bus_er char *ri = NULL, *rt = NULL; const char *root, *init; Manager *m = userdata; + struct statvfs svfs; + uint64_t available; int r; assert(message); assert(m); + if (statvfs("/run/systemd", &svfs) < 0) + return sd_bus_error_set_errnof(error, errno, "Failed to statvfs(/run/systemd): %m"); + + available = (uint64_t) svfs.f_bfree * (uint64_t) svfs.f_bsize; + + if (available < RELOAD_DISK_SPACE_MIN) { + char fb_available[FORMAT_BYTES_MAX], fb_need[FORMAT_BYTES_MAX]; + log_warning("Dangerously low amount of free space on /run/systemd, root switching operation might not complete successfuly. " + "Currently, %s are free, but %s are suggested. Proceeding anyway.", + format_bytes(fb_available, sizeof(fb_available), available), + format_bytes(fb_need, sizeof(fb_need), RELOAD_DISK_SPACE_MIN)); + } + r = mac_selinux_access_check(message, "reboot", error); if (r < 0) return r; diff --git a/src/core/dbus-manager.h b/src/core/dbus-manager.h index 36a2e9481b1..9f3222da28f 100644 --- a/src/core/dbus-manager.h +++ b/src/core/dbus-manager.h @@ -26,3 +26,5 @@ extern const sd_bus_vtable bus_manager_vtable[]; void bus_manager_send_finished(Manager *m, usec_t firmware_usec, usec_t loader_usec, usec_t kernel_usec, usec_t initrd_usec, usec_t userspace_usec, usec_t total_usec); void bus_manager_send_reloading(Manager *m, bool active); void bus_manager_send_change_signal(Manager *m); + +int verify_run_space_and_log(const char *message); diff --git a/src/core/manager.c b/src/core/manager.c index d83c5ef5e21..e4da945777b 100644 --- a/src/core/manager.c +++ b/src/core/manager.c @@ -1984,7 +1984,9 @@ static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t if (MANAGER_IS_SYSTEM(m)) { /* This is for compatibility with the * original sysvinit */ - m->exit_code = MANAGER_REEXECUTE; + r = verify_run_space_and_log("Refusing to reexecute"); + if (r >= 0) + m->exit_code = MANAGER_REEXECUTE; break; } @@ -2061,7 +2063,9 @@ static int manager_dispatch_signal_fd(sd_event_source *source, int fd, uint32_t } case SIGHUP: - m->exit_code = MANAGER_RELOAD; + r = verify_run_space_and_log("Refusing to reload"); + if (r >= 0) + m->exit_code = MANAGER_RELOAD; break; default: { @@ -2432,18 +2436,22 @@ void manager_send_unit_plymouth(Manager *m, Unit *u) { } int manager_open_serialization(Manager *m, FILE **_f) { - const char *path; int fd = -1; FILE *f; assert(_f); - path = MANAGER_IS_SYSTEM(m) ? "/run/systemd" : "/tmp"; - fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC); - if (fd < 0) - return -errno; + fd = memfd_create("systemd-serialization", MFD_CLOEXEC); + if (fd < 0) { + const char *path; - log_debug("Serializing state to %s", path); + path = MANAGER_IS_SYSTEM(m) ? "/run/systemd" : "/tmp"; + fd = open_tmpfile_unlinkable(path, O_RDWR|O_CLOEXEC); + if (fd < 0) + return -errno; + log_debug("Serializing state to %s.", path); + } else + log_debug("Serializing state to memfd."); f = fdopen(fd, "w+"); if (!f) { diff --git a/src/libsystemd/sd-bus/bus-common-errors.c b/src/libsystemd/sd-bus/bus-common-errors.c index c9fd79e3b42..b40ba2520c3 100644 --- a/src/libsystemd/sd-bus/bus-common-errors.c +++ b/src/libsystemd/sd-bus/bus-common-errors.c @@ -47,6 +47,7 @@ BUS_ERROR_MAP_ELF_REGISTER const sd_bus_error_map bus_common_errors[] = { SD_BUS_ERROR_MAP(BUS_ERROR_SCOPE_NOT_RUNNING, EHOSTDOWN), SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_DYNAMIC_USER, ESRCH), SD_BUS_ERROR_MAP(BUS_ERROR_NOT_REFERENCED, EUNATCH), + SD_BUS_ERROR_MAP(BUS_ERROR_DISK_FULL, ENOSPC), SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_MACHINE, ENXIO), SD_BUS_ERROR_MAP(BUS_ERROR_NO_SUCH_IMAGE, ENOENT), diff --git a/src/libsystemd/sd-bus/bus-common-errors.h b/src/libsystemd/sd-bus/bus-common-errors.h index 525b79fa77f..4523be05cec 100644 --- a/src/libsystemd/sd-bus/bus-common-errors.h +++ b/src/libsystemd/sd-bus/bus-common-errors.h @@ -43,6 +43,7 @@ #define BUS_ERROR_SCOPE_NOT_RUNNING "org.freedesktop.systemd1.ScopeNotRunning" #define BUS_ERROR_NO_SUCH_DYNAMIC_USER "org.freedesktop.systemd1.NoSuchDynamicUser" #define BUS_ERROR_NOT_REFERENCED "org.freedesktop.systemd1.NotReferenced" +#define BUS_ERROR_DISK_FULL "org.freedesktop.systemd1.DiskFull" #define BUS_ERROR_NO_SUCH_MACHINE "org.freedesktop.machine1.NoSuchMachine" #define BUS_ERROR_NO_SUCH_IMAGE "org.freedesktop.machine1.NoSuchImage"