This is a stability fix, not a security fix, because the affected -o
option can only be used by root and it takes a modified passwd file.
If a gecos field for a user has BUFSIZ characters without commas and an
equals sign (i.e. a huge slop/extra field) and chfn is called with -o,
then a buffer overflow occurs.
It is not possible to trigger this with shadow tools. Therefore, the
passwd file must be modified manually.
I have fixed this unlikely case the easiest and cleanest way possible.
Since chfn bails out if more than 80 characters excluding commas are
supposed to be written into gecos field, we can stop processing early on
if -o argument is too long.
This is merely a stability fix, not a security fix.
As the root user, it is possible to set time values which later on
result in signed integer overflows.
For this to work, an sgetspent implementation must be used which
supports long values (glibc on amd64 only parses 32 bit, not 64).
Either use musl or simply call configure with following environment
variable:
$ ac_cv_func_sgetspent=no ./configure
Also it is recommended to compile with -fsanitize=undefined or
-ftrapv to see these issues easily.
Examples to trigger issues when calling "chage -l user":
Currently this has three functions: one which returns the
list of subuid ranges for a user, one returning the subgids,
and one which frees the ranges lists.
I might be mistaken about what -disable-man means; some of
the code suggests it means just don't re-generate them, but
not totally ignore them. But that doesn't seem to really work,
so let's just ignore man/ when -disable-man.
Remove --disable-shared. I'm not sure why it was there, but it stems
from long, long ago, and I suspect it comes from some ancient
toolchain bug.
Create a tests/run_some, a shorter version of run_all. I'll
slowly add tests to this as I verify they work, then I can
work on fixing the once which don't.
Also, don't touch man/ if not -enable-man.
Changelog:
Apr 22: change the subid list api as recomended by Dan Walsh.
Apr 23: implement get_subid_owner
Apr 24: implement range add/release
Apr 25: finish tests and rebase
May 10: make @owner const
According to crypt(5), MD5 and DES should not be used for new
hashes. Also the default number of SHA rounds chosen by libc is orders
of magnitude too low for modern hardware. Let's warn the users about
weak choices.
Geoffrey Krug [Wed, 12 Feb 2020 20:21:21 +0000 (20:21 +0000)]
Removed hard-coded default mail spool in useradd
The useradd program should be consistent with userdel and usermod and use the
MAIL_SPOOL_DIR variable as the default spool, if it is defined. Otherwise,
don't create a new mailbox, because it won't be cleaned up by userdel when run
with the -r flag.
Tomas Mraz [Mon, 20 Jan 2020 12:58:07 +0000 (13:58 +0100)]
Do not mistake a regular user process for a namespaced one
In case there is a regular user with a process running on a system
with uid falling into a namespaced uid range of another user.
The user with the colliding namespaced uid range will not be
allowed to be deleted without forcing the action with -f.
The user_busy() is adjusted to check whether the suspected process
is really a namespaced process in a different namespace.
updated Dutch translation for shadow version 4.8 (pot file from 2019-12-01).
I updated the translation for Debian
and on request of the Debian package maintainer Bálint Réczey I am creating this pull request
Tomas Mraz [Thu, 16 Jan 2020 11:55:30 +0000 (12:55 +0100)]
Make the check for non-executable shell only a warning.
Although it is a good idea to check for an inadvertent typo
in the shell name it is possible that the shell might not be present
on the system yet when the user is added.
Duncan Overbruck [Sat, 11 Jan 2020 21:19:37 +0000 (22:19 +0100)]
add new HOME_MODE login.defs(5) option
This option can be used to set a separate mode for useradd(8) and
newusers(8) to create the home directories with.
If this option is not set, the current behavior of using UMASK
or the default umask is preserved.
There are many distributions that set UMASK to 077 by default just
to create home directories not readable by others and use things like
/etc/profile, bashrc or sudo configuration files to set a less
restrictive
umask. This has always resulted in bug reports because it is hard
to follow as users tend to change files like bashrc and are not about
setting the umask to counteract the umask set in /etc/login.defs.
A recent change in sudo has also resulted in many bug reports about
this. sudo now tries to respect the umask set by pam modules and on
systems where pam does not set a umask, the login.defs UMASK value is
used.
Duncan Overbruck [Sat, 11 Jan 2020 21:19:37 +0000 (22:19 +0100)]
add new HOME_MODE login.defs(5) option
This option can be used to set a separate mode for useradd(8) and
newusers(8) to create the home directories with.
If this option is not set, the current behavior of using UMASK
or the default umask is preserved.
There are many distributions that set UMASK to 077 by default just
to create home directories not readable by others and use things like
/etc/profile, bashrc or sudo configuration files to set a less
restrictive
umask. This has always resulted in bug reports because it is hard
to follow as users tend to change files like bashrc and are not about
setting the umask to counteract the umask set in /etc/login.defs.
A recent change in sudo has also resulted in many bug reports about
this. sudo now tries to respect the umask set by pam modules and on
systems where pam does not set a umask, the login.defs UMASK value is
used.
`make` runs each line in a shell and bails out on error,
however, the shell is not started with `-e`, so commands in
`for` loops can fail without the error actually causing
`make` to bail out with a failure status.
For instance, the following make snippet will end
successfully, printing 'SUCCESS', despite the first `chmod`
failing:
all:
touch a b
for i in a-missing-file a b; do \
chmod 666 $$i; \
done
@echo SUCCESS
To prevent wrong paths in install scripts from remaining
unnoticed, let's activate `set -e` in the `for` loop
subshells.
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Michael Weiser [Tue, 17 Dec 2019 20:13:07 +0000 (21:13 +0100)]
man: Don't suggest making groupmems user-writeable
Suggesting mode 2770 is dangerous because it makes the binary writeable
by all members of the owning group which is supposed to be normal
end-users. Suggest 2710 instead as is usual for s[ug]id binaries,
allowing execution but neither reading nor writing.
Signed-off-by: Michael Weiser <michael.weiser@gmx.de>