[Pkg-sysvinit-devel] Bug#769743: sulogin: crashes when /etc/passwd is missing

[Christian Hofstaedtler]

Package: sysvinit-utils
Version: 2.88dsf-57
Severity: important

sulogin crashes when /etc/passwd is unavailable.

See the following code from sulogin.c:

    if ((pwd = getrootpwent(opt_e)) == NULL) {
       fprintf(stderr, "sulogin: cannot open password database!\n");
       sleep(2);
    }

    ...
    if ((strcmp(pwd->pw_passwd, "*") == 0) ||
        (strcmp(pwd->pw_passwd, "!") == 0)) {
         ...

When the fprintf in the first if() case happens, pwd is NULL, and
de-referencing that crashes in the second if.

This affects users where initramfs-tools cannot succesfully mount /,
leaving them with a more than necessary broken system.

Thanks,
Christian