Hello,
recently I faced with the issue when user who has configured shell /usr/bin/sh wasn't able to logon via ftp (vsftpd).
When checked pam modules found no useful and started comment them one by one. On commented pam_shells.so user logged on successfully.
Then, when checked content of /etc/shells I was surprised when found no /usr/bin/sh, but /bin/bash exists (both are part of bash-4.3-83.23.1.x86_64)
Therefore I have a questions: why one of default bash shell paths is not part of valid logon shells and is there any concerns to amend /etc/shells with /usr/bin/sh?
Thank you in advance.
Regards,
Ivan

# rpm -qf /etc/shells
aaa_base-13.2+git20140911.61c1681-38.13.1.x86_64

# cat /etc/SuSE-release
SUSE Linux Enterprise Server 12 (x86_64)
VERSION = 12
PATCHLEVEL = 3
# This file is deprecated and will be removed in a future service pack or release.
# Please check /etc/os-release for details about this release.

# cat /etc/os-release
NAME="SLES"
VERSION="12-SP3"
VERSION_ID="12.3"
PRETTY_NAME="SUSE Linux Enterprise Server 12 SP3"
ID="sles"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:suse:sles_sap:12:sp3"