SU: Permissão negada / bin / sh

Question

Eu adicionei um novo usuário no sistema:

$ useradd new_user

Quando tento mudar de root para new_user , recebo este erro:

$ su new_user
permission denied /bin/sh
$grep new_user /etc/passwd
new_user:x:2001:4001::/home/new_user:/bin/sh
$/bin/ls -ld /bin
dr-xr-xr-x    2 root     root          4096 Jan  1 00:07 /bin
$/bin/ls -ld /bin/sh
lrwxrwxrwx    1 root     root            20 Jan  1 00:07 /bin/sh -> /etc/alternatives/sh
$/bin/ls -ld /etc/alternatives/sh
lrwxrwxrwx    1 root     root             9 Jan  1 00:07 /etc/alternatives/sh -> /bin/bash
$/bin/ls -ld /bin/bash
-r-xr-x---    1 root     shell       700076 May 27  2014 /bin/bash