diff --git a/src/shared/condition.c b/src/shared/condition.c index aa34e1e285..310ffcbdc6 100644 --- a/src/shared/condition.c +++ b/src/shared/condition.c @@ -338,31 +338,36 @@ static int condition_test_cpus(Condition *c, char **env) { static int condition_test_user(Condition *c, char **env) { uid_t id; int r; - _cleanup_free_ char *username = NULL; - const char *u; assert(c); assert(c->parameter); assert(c->type == CONDITION_USER); + /* Do the quick&easy comparisons first, and only parse the UID later. */ + if (streq(c->parameter, "root")) + return getuid() == 0 || geteuid() == 0; + if (streq(c->parameter, NOBODY_USER_NAME)) + return getuid() == UID_NOBODY || geteuid() == UID_NOBODY; + if (streq(c->parameter, "@system")) + return uid_is_system(getuid()) || uid_is_system(geteuid()); + r = parse_uid(c->parameter, &id); if (r >= 0) return id == getuid() || id == geteuid(); - if (streq("@system", c->parameter)) - return uid_is_system(getuid()) || uid_is_system(geteuid()); + if (getpid_cached() == 1) /* We already checked for "root" above, and we know that + * PID 1 is running as root, hence we know it cannot match. */ + return false; - username = getusername_malloc(); + /* getusername_malloc() may do an nss lookup, which is not allowed in PID 1. */ + _cleanup_free_ char *username = getusername_malloc(); if (!username) return -ENOMEM; if (streq(username, c->parameter)) return 1; - if (getpid_cached() == 1) - return streq(c->parameter, "root"); - - u = c->parameter; + const char *u = c->parameter; r = get_user_creds(&u, &id, NULL, NULL, NULL, USER_CREDS_ALLOW_MISSING); if (r < 0) return 0;