diff options
| -rw-r--r-- | libbb/change_identity.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/libbb/change_identity.c b/libbb/change_identity.c index 619db09..d48d863 100644 --- a/libbb/change_identity.c +++ b/libbb/change_identity.c @@ -33,9 +33,28 @@ /* Become the user and group(s) specified by PW. */ void FAST_FUNC change_identity(const struct passwd *pw) { - if (initgroups(pw->pw_name, pw->pw_gid) == -1) - bb_perror_msg_and_die("can't set groups"); + int res; + + res = initgroups(pw->pw_name, pw->pw_gid); endgrent(); /* helps to close a fd used internally by libc */ + + if (res != 0) { + /* + * If initgroups() fails because a system call is unimplemented + * then we are running on a Linux kernel compiled without multiuser + * support (CONFIG_MULTIUSER is not defined). + * + * If we are running without multiuser support *and* the target uid + * already matches the current uid then we can skip the change of + * identity. + */ + if (errno == ENOSYS && pw->pw_uid == getuid()) { + return; + } + + bb_perror_msg_and_die("can't set groups"); + } + xsetgid(pw->pw_gid); xsetuid(pw->pw_uid); } |