Submitted By: Douglas R. Reno Date: 2019-02-21 Initial Package Version: 240 Upstream Status: Applied Origin: Upstream / Self (modifications) Description: Fix CVE-2018-16865 and CVE-2018-18684 memory corruption vulnerabilities that lead to stack overflows, which can lead to Arbitrary Code Execution (ACE). Fix CVE-2019-6454, a remotely-exploitable stack overflow vulnerability that can cause PID1 to crash via D-Bus. diff -Naurp systemd-240/src/basic/io-util.c systemd-240-new/src/basic/io-util.c --- systemd-240/src/basic/io-util.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/basic/io-util.c 2019-02-20 23:24:40.591607063 -0600 @@ -8,6 +8,7 @@ #include #include "io-util.h" +#include "string-util.h" #include "time-util.h" int flush_fd(int fd) { @@ -252,3 +253,12 @@ ssize_t sparse_write(int fd, const void return q - (const uint8_t*) p; } + +char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) { + char *x; + + x = strappend(field, value); + if (x) + iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x); + return x; +} diff -Naurp systemd-240/src/basic/io-util.h systemd-240-new/src/basic/io-util.h --- systemd-240/src/basic/io-util.h 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/basic/io-util.h 2019-02-20 23:24:40.591607063 -0600 @@ -71,3 +71,4 @@ static inline bool FILE_SIZE_VALID_OR_IN #define IOVEC_MAKE(base, len) (struct iovec) IOVEC_INIT(base, len) #define IOVEC_INIT_STRING(string) IOVEC_INIT((char*) string, strlen(string)) #define IOVEC_MAKE_STRING(string) (struct iovec) IOVEC_INIT_STRING(string) +char* set_iovec_string_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value); diff -Naurp systemd-240/src/coredump/coredump.c systemd-240-new/src/coredump/coredump.c --- systemd-240/src/coredump/coredump.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/coredump/coredump.c 2019-02-20 23:24:40.591607063 -0600 @@ -1062,19 +1062,10 @@ static int send_iovec(const struct iovec return 0; } -static char* set_iovec_field(struct iovec *iovec, size_t *n_iovec, const char *field, const char *value) { - char *x; - - x = strappend(field, value); - if (x) - iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(x); - return x; -} - static char* set_iovec_field_free(struct iovec *iovec, size_t *n_iovec, const char *field, char *value) { char *x; - x = set_iovec_field(iovec, n_iovec, field, value); + x = set_iovec_string_field(iovec, n_iovec, field, value); free(value); return x; } @@ -1124,36 +1115,36 @@ static int gather_pid_metadata( disable_coredumps(); } - set_iovec_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]); + set_iovec_string_field(iovec, n_iovec, "COREDUMP_UNIT=", context[CONTEXT_UNIT]); } if (cg_pid_get_user_unit(pid, &t) >= 0) set_iovec_field_free(iovec, n_iovec, "COREDUMP_USER_UNIT=", t); /* The next few are mandatory */ - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_PID=", context[CONTEXT_PID])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_UID=", context[CONTEXT_UID])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_GID=", context[CONTEXT_GID])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL=", context[CONTEXT_SIGNAL])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_RLIMIT=", context[CONTEXT_RLIMIT])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_HOSTNAME=", context[CONTEXT_HOSTNAME])) return log_oom(); - if (!set_iovec_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM])) + if (!set_iovec_string_field(iovec, n_iovec, "COREDUMP_COMM=", context[CONTEXT_COMM])) return log_oom(); if (context[CONTEXT_EXE] && - !set_iovec_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE])) + !set_iovec_string_field(iovec, n_iovec, "COREDUMP_EXE=", context[CONTEXT_EXE])) return log_oom(); if (sd_pid_get_session(pid, &t) >= 0) @@ -1221,7 +1212,7 @@ static int gather_pid_metadata( iovec[(*n_iovec)++] = IOVEC_MAKE_STRING(t); if (safe_atoi(context[CONTEXT_SIGNAL], &signo) >= 0 && SIGNAL_VALID(signo)) - set_iovec_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo)); + set_iovec_string_field(iovec, n_iovec, "COREDUMP_SIGNAL_NAME=SIG", signal_to_string(signo)); return 0; /* we successfully acquired all metadata */ } diff -Naurp systemd-240/src/journal/journald-native.c systemd-240-new/src/journal/journald-native.c --- systemd-240/src/journal/journald-native.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/journal/journald-native.c 2019-02-20 23:24:40.591607063 -0600 @@ -141,6 +141,11 @@ static int server_process_entry( } /* A property follows */ + if (n > ENTRY_FIELD_COUNT_MAX) { + log_debug("Received an entry that has more than " STRINGIFY(ENTRY_FIELD_COUNT_MAX) " fields, ignoring entry."); + r = 1; + goto finish; + } /* n existing properties, 1 new, +1 for _TRANSPORT */ if (!GREEDY_REALLOC(iovec, m, diff -Naurp systemd-240/src/journal/journald-server.c systemd-240-new/src/journal/journald-server.c --- systemd-240/src/journal/journald-server.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/journal/journald-server.c 2019-02-20 23:24:40.591607063 -0600 @@ -905,6 +905,7 @@ static void dispatch_message_real( pid_t object_pid) { char source_time[sizeof("_SOURCE_REALTIME_TIMESTAMP=") + DECIMAL_STR_MAX(usec_t)]; + _cleanup_free_ char *cmdline1 = NULL, *cmdline2 = NULL; uid_t journal_uid; ClientContext *o; @@ -921,20 +922,23 @@ static void dispatch_message_real( IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->uid, uid_t, uid_is_valid, UID_FMT, "_UID"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->gid, gid_t, gid_is_valid, GID_FMT, "_GID"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->cmdline, "_CMDLINE"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE"); + IOVEC_ADD_STRING_FIELD(iovec, n, c->comm, "_COMM"); /* At most TASK_COMM_LENGTH (16 bytes) */ + IOVEC_ADD_STRING_FIELD(iovec, n, c->exe, "_EXE"); /* A path, so at most PATH_MAX (4096 bytes) */ - IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT"); + if (c->cmdline) + /* At most _SC_ARG_MAX (2MB usually), which is too large to put on the stack. + * Let's use a heap allocation for this one now. */ + cmdline1 = set_iovec_string_field(iovec, &n, "_CMDLINE=", c->cmdline); + IOVEC_ADD_STRING_FIELD(iovec, n, c->capeff, "_CAP_EFFECTIVE"); /* Read from /proc/.../status */ + IOVEC_ADD_SIZED_FIELD(iovec, n, c->label, c->label_size, "_SELINUX_CONTEXT"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "_AUDIT_SESSION"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->loginuid, uid_t, uid_is_valid, UID_FMT, "_AUDIT_LOGINUID"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP"); + IOVEC_ADD_STRING_FIELD(iovec, n, c->cgroup, "_SYSTEMD_CGROUP"); /* A path */ IOVEC_ADD_STRING_FIELD(iovec, n, c->session, "_SYSTEMD_SESSION"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, c->owner_uid, uid_t, uid_is_valid, UID_FMT, "_SYSTEMD_OWNER_UID"); - IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT"); + IOVEC_ADD_STRING_FIELD(iovec, n, c->unit, "_SYSTEMD_UNIT"); /* Unit names are bound by UNIT_NAME_MAX */ IOVEC_ADD_STRING_FIELD(iovec, n, c->user_unit, "_SYSTEMD_USER_UNIT"); IOVEC_ADD_STRING_FIELD(iovec, n, c->slice, "_SYSTEMD_SLICE"); IOVEC_ADD_STRING_FIELD(iovec, n, c->user_slice, "_SYSTEMD_USER_SLICE"); @@ -955,13 +959,14 @@ static void dispatch_message_real( IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->uid, uid_t, uid_is_valid, UID_FMT, "OBJECT_UID"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->gid, gid_t, gid_is_valid, GID_FMT, "OBJECT_GID"); + /* See above for size limits, only ->cmdline may be large, so use a heap allocation for it.*/ IOVEC_ADD_STRING_FIELD(iovec, n, o->comm, "OBJECT_COMM"); IOVEC_ADD_STRING_FIELD(iovec, n, o->exe, "OBJECT_EXE"); - IOVEC_ADD_STRING_FIELD(iovec, n, o->cmdline, "OBJECT_CMDLINE"); - IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE"); + if (o->cmdline) + cmdline2 = set_iovec_string_field(iovec, &n, "OBJECT_CMDLINE=", o->cmdline); + IOVEC_ADD_STRING_FIELD(iovec, n, o->capeff, "OBJECT_CAP_EFFECTIVE"); IOVEC_ADD_SIZED_FIELD(iovec, n, o->label, o->label_size, "OBJECT_SELINUX_CONTEXT"); - IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->auditid, uint32_t, audit_session_is_valid, "%" PRIu32, "OBJECT_AUDIT_SESSION"); IOVEC_ADD_NUMERIC_FIELD(iovec, n, o->loginuid, uid_t, uid_is_valid, UID_FMT, "OBJECT_AUDIT_LOGINUID"); diff -Naurp systemd-240/src/libsystemd/sd-bus/bus-internal.c systemd-240-new/src/libsystemd/sd-bus/bus-internal.c --- systemd-240/src/libsystemd/sd-bus/bus-internal.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/libsystemd/sd-bus/bus-internal.c 2019-02-20 23:24:54.586681901 -0600 @@ -43,7 +43,7 @@ bool object_path_is_valid(const char *p) if (slash) return false; - return true; + return (q - p) <= BUS_PATH_SIZE_MAX; } char* object_path_startswith(const char *a, const char *b) { diff -Naurp systemd-240/src/libsystemd/sd-bus/bus-internal.h systemd-240-new/src/libsystemd/sd-bus/bus-internal.h --- systemd-240/src/libsystemd/sd-bus/bus-internal.h 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/libsystemd/sd-bus/bus-internal.h 2019-02-20 23:24:54.586681901 -0600 @@ -332,6 +332,10 @@ struct sd_bus { #define BUS_MESSAGE_SIZE_MAX (128*1024*1024) #define BUS_AUTH_SIZE_MAX (64*1024) +/* Note that the D-Bus specification states that bus paths shall have no size limit. We enforce here one + * anyway, since truly unbounded strings are a security problem. The limit we pick is relatively large however, + * to not clash unnecessarily with real-life applications. */ +#define BUS_PATH_SIZE_MAX (64*1024) #define BUS_CONTAINER_DEPTH 128 diff -Naurp systemd-240/src/libsystemd/sd-bus/bus-objects.c systemd-240-new/src/libsystemd/sd-bus/bus-objects.c --- systemd-240/src/libsystemd/sd-bus/bus-objects.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/libsystemd/sd-bus/bus-objects.c 2019-02-20 23:24:54.586681901 -0600 @@ -1133,7 +1133,8 @@ static int object_manager_serialize_path const char *path, sd_bus_error *error) { - char *prefix; + _cleanup_free_ char *prefix = NULL; + size_t pl; int r; assert(bus); @@ -1149,7 +1150,12 @@ static int object_manager_serialize_path return 0; /* Second, add fallback vtables registered for any of the prefixes */ - prefix = alloca(strlen(path) + 1); + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { r = object_manager_serialize_path(bus, reply, prefix, path, true, error); if (r < 0) @@ -1345,6 +1351,7 @@ static int object_find_and_run( } int bus_process_object(sd_bus *bus, sd_bus_message *m) { + _cleanup_free_ char *prefix = NULL; int r; size_t pl; bool found_object = false; @@ -1369,9 +1376,12 @@ int bus_process_object(sd_bus *bus, sd_b assert(m->member); pl = strlen(m->path); - do { - char prefix[pl+1]; + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + do { bus->nodes_modified = false; r = object_find_and_run(bus, m, m->path, false, &found_object); @@ -1498,9 +1508,16 @@ static int bus_find_parent_object_manage n = hashmap_get(bus->nodes, path); if (!n) { - char *prefix; - prefix = alloca(strlen(path) + 1); + _cleanup_free_ char *prefix = NULL; + size_t pl; + + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { n = hashmap_get(bus->nodes, prefix); if (n) @@ -2083,8 +2100,9 @@ _public_ int sd_bus_emit_properties_chan const char *interface, char **names) { + _cleanup_free_ char *prefix = NULL; bool found_interface = false; - char *prefix; + size_t pl; int r; assert_return(bus, -EINVAL); @@ -2105,6 +2123,12 @@ _public_ int sd_bus_emit_properties_chan BUS_DONT_DESTROY(bus); + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + do { bus->nodes_modified = false; @@ -2114,7 +2138,6 @@ _public_ int sd_bus_emit_properties_chan if (bus->nodes_modified) continue; - prefix = alloca(strlen(path) + 1); OBJECT_PATH_FOREACH_PREFIX(prefix, path) { r = emit_properties_changed_on_interface(bus, prefix, path, interface, true, &found_interface, names); if (r != 0) @@ -2246,7 +2269,8 @@ static int object_added_append_all_prefi static int object_added_append_all(sd_bus *bus, sd_bus_message *m, const char *path) { _cleanup_set_free_ Set *s = NULL; - char *prefix; + _cleanup_free_ char *prefix = NULL; + size_t pl; int r; assert(bus); @@ -2291,7 +2315,12 @@ static int object_added_append_all(sd_bu if (bus->nodes_modified) return 0; - prefix = alloca(strlen(path) + 1); + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { r = object_added_append_all_prefix(bus, m, s, prefix, path, true); if (r < 0) @@ -2430,7 +2459,8 @@ static int object_removed_append_all_pre static int object_removed_append_all(sd_bus *bus, sd_bus_message *m, const char *path) { _cleanup_set_free_ Set *s = NULL; - char *prefix; + _cleanup_free_ char *prefix = NULL; + size_t pl; int r; assert(bus); @@ -2462,7 +2492,12 @@ static int object_removed_append_all(sd_ if (bus->nodes_modified) return 0; - prefix = alloca(strlen(path) + 1); + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { r = object_removed_append_all_prefix(bus, m, s, prefix, path, true); if (r < 0) @@ -2612,7 +2647,8 @@ static int interfaces_added_append_one( const char *path, const char *interface) { - char *prefix; + _cleanup_free_ char *prefix = NULL; + size_t pl; int r; assert(bus); @@ -2626,7 +2662,12 @@ static int interfaces_added_append_one( if (bus->nodes_modified) return 0; - prefix = alloca(strlen(path) + 1); + pl = strlen(path); + assert(pl <= BUS_PATH_SIZE_MAX); + prefix = new(char, pl + 1); + if (!prefix) + return -ENOMEM; + OBJECT_PATH_FOREACH_PREFIX(prefix, path) { r = interfaces_added_append_one_prefix(bus, m, prefix, path, interface, true); if (r != 0) diff -Naurp systemd-240/src/libsystemd/sd-bus/bus-socket.c systemd-240-new/src/libsystemd/sd-bus/bus-socket.c --- systemd-240/src/libsystemd/sd-bus/bus-socket.c 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/libsystemd/sd-bus/bus-socket.c 2019-02-20 23:24:54.587681907 -0600 @@ -1072,7 +1072,7 @@ static int bus_socket_read_message_need( } static int bus_socket_make_message(sd_bus *bus, size_t size) { - sd_bus_message *t; + sd_bus_message *t = NULL; void *b; int r; @@ -1097,7 +1097,9 @@ static int bus_socket_make_message(sd_bu bus->fds, bus->n_fds, NULL, &t); - if (r < 0) { + if (r == -EBADMSG) + log_debug_errno(r, "Received invalid message from connection %s, dropping.", strna(bus->description)); + else if (r < 0) { free(b); return r; } @@ -1108,7 +1110,8 @@ static int bus_socket_make_message(sd_bu bus->fds = NULL; bus->n_fds = 0; - bus->rqueue[bus->rqueue_size++] = t; + if (t) + bus->rqueue[bus->rqueue_size++] = t; return 1; } diff -Naurp systemd-240/src/shared/journal-importer.h systemd-240-new/src/shared/journal-importer.h --- systemd-240/src/shared/journal-importer.h 2018-12-21 12:53:33.000000000 -0600 +++ systemd-240-new/src/shared/journal-importer.h 2019-02-20 23:24:40.591607063 -0600 @@ -21,6 +21,10 @@ #endif #define LINE_CHUNK 8*1024u +/* The maximum number of fields in an entry */ +/* Set to 1024 for now */ +#define ENTRY_FIELD_COUNT_MAX 1024 + struct iovec_wrapper { struct iovec *iovec; size_t size_bytes;