bug#24138: SIGSEGV of useradd (from shadow package)

[Ludovic Courtès]

Hello!

Tomáš Čech <address@hidden> skribis:

> It seems to be easy to crash useradd (from shadow package).

Is it on GuixSD?

> from strace:
>
> read(3, "account required pam_deny.so \nau"..., 4096) = 223
> open("/gnu/store/2xmwkq2ycwk89xlxnvib5wnjaacfy0rg-linux-pam-1.2.1/lib/security/pam_deny.so",
>  O_RDONLY|O_CLOEXEC) = 5
> read(5, 
> "\177ELF\2\1\1\0\0\0\0\0\0\0\0\0\3\0>\0\1\0\0\0\340\6\0\0\0\0\0\0"..., 832) = 
> 832
> fstat(5, {st_mode=S_IFREG|0555, st_size=6728, ...}) = 0
> mmap(NULL, 2100200, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 5, 0) = 
> 0x7fb8b447c000
> mprotect(0x7fb8b447d000, 2093056, PROT_NONE) = 0
> mmap(0x7fb8b467c000, 4096, PROT_READ|PROT_WRITE, 
> MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 5, 0) = 0x7fb8b467c000
> close(5)                                = 0
> --- SIGSEGV {si_signo=SIGSEGV, si_code=SEGV_MAPERR, si_addr=0x7fb8b3d1bda8} 
> ---

Could you check in the ‘strace’ output whether PAM modules build with
another libc are being loaded?

Thanks for your report!

Ludo’.