Adding function check_fds to new file fd.c. The function check_fds
should be called in every setuid/setgid program.
Co-developed-by: Alejandro Colomar <alx@kernel.org>
The variable declarations for the buffers have been aligned in this
commit, so that they appear in the diff, making it easier to review.
Some important but somewhat tangent changes included in this commit:
- lib/nss.c: The size was being defined as 65, but then used as 64.
That was a bug, although not an important one; we were just wasting
one byte. Fix that while we replace snprintf() by SNPRINTF(), which
will get the size from sizeof(), and thus will use the real size.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
We'll expand the contents in a following commit, so let's move the file
to a more generic name, have a dedicated header, and update includes.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
Use the new header for xstrdup()
Signed-off-by: Alejandro Colomar <alx@kernel.org>
In variadic functions we still do the cast. In POSIX, it's not
necessary, since NULL is required to be of type 'void *', and 'void *'
is guaranteed to have the same alignment and representation as 'char *'.
However, since ISO C still doesn't mandate that, and moreover they're
doing dubious stuff by adding nullptr, let's be on the cautious side.
Also, C++ requires that NULL is _not_ 'void *', but either plain 0 or
some magic stuff.
Signed-off-by: Alejandro Colomar <alx@kernel.org>
When the caller may not change the room number, work phone, or
home number, then rather than prompting for the new one it will
print the existing one. But due to a typo it printed the full name
in place of each of those.
Fix the fields being printed.
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Closes#325
Add a new subid_init() function which can be used to specify the
stream on which error messages should be printed. (If you want to
get fancy you can redirect that to memory :) If subid_init() is
not called, use stderr. If NULL is passed, then /dev/null will
be used.
This patch also fixes up the 'Prog', which previously had to be
defined by any program linking against libsubid. Now, by default
in libsubid it will show (subid). Once subid_init() is called,
it will use the first variable passed to subid_init().
Signed-off-by: Serge Hallyn <serge@hallyn.com>
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.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Using hard-coded access vector ids is deprecated and can lead to issues with custom SELinux policies.
Switch to `selinux_check_access()`.
Also use the libselinux log callback and log if available to audit.
This makes it easier for users to catch SELinux denials.
Drop legacy shortcut logic for passwd, which avoided a SELinux check if uid 0 changes a password of a user which username equals the current SELinux user identifier.
Nowadays usernames rarely match SELinux user identifiers and the benefit of skipping a SELinux check is negligible.
Signed-off-by: Christian Göttsche <cgzones@googlemail.com>
Some distributions, notably Fedora, have the following order of nsswitch
modules by default:
passwd: sss files
group: sss files
The advantage of serving local users through SSSD is that the nss_sss
module has a fast mmapped-cache that speeds up NSS lookups compared to
accessing the disk an opening the files on each NSS request.
Traditionally, this has been done with the help of nscd, but using nscd
in parallel with sssd is cumbersome, as both SSSD and nscd use their own
independent caching, so using nscd in setups where sssd is also serving
users from some remote domain (LDAP, AD, ...) can result in a bit of
unpredictability.
More details about why Fedora chose to use sss before files can be found
on e.g.:
https://fedoraproject.org//wiki/Changes/SSSDCacheForLocalUsers
or:
https://docs.pagure.org/SSSD.sssd/design_pages/files_provider.html
Now, even though sssd watches the passwd and group files with the help
of inotify, there can still be a small window where someone requests a
user or a group, finds that it doesn't exist, adds the entry and checks
again. Without some support in shadow-utils that would explicitly drop
the sssd caches, the inotify watch can fire a little late, so a
combination of commands like this:
getent passwd user || useradd user; getent passwd user
can result in the second getent passwd not finding the newly added user
as the racy behaviour might still return the cached negative hit from
the first getent passwd.
This patch more or less copies the already existing support that
shadow-utils had for dropping nscd caches, except using the "sss_cache"
tool that sssd ships.
passwd, shadow, group, gshadow etc. can be managed via nss -
e.g. system default accounts can be specified using nss_altfiles,
rather than in /etc/. Thus despite having default accounts, these
files can be missing on disk and thus should be opened with O_CREATE
whenever they are attempted to be opened in O_RDWR modes.
src/chsh.c, src/groupadd.c, src/groupdel.c, src/groupmems.c,
src/groupmod.c, src/newusers.c, src/useradd.c, src/userdel.c,
src/usermod.c: Provide the PAM error
message instead of our own, and log error to syslog.
* src/groupmems.c: Exit with exit rather than fail_exit in usage().
* src/newusers.c: Check the number of arguments.
* src/newusers.c: Do not create the home directory when it is not
changed.
* src/useradd.c: Set the group password to "!" rather "x" if there
are no gshadow file.
* src/userdel.c, src/newusers.c, src/chpasswd.c, src/chfn.c,
src/groupmems.c, src/usermod.c, src/groupdel.c, src/chgpasswd.c,
src/useradd.c, src/groupmod.c, src/groupadd.c, src/chage.c,
src/chsh.c: If the username cannot be determined, report it as
such (not a PAM authentication failure).
src/groupmems.c, src/usermod.c, src/groupdel.c, src/chgpasswd.c,
src/useradd.c, src/groupmod.c, src/groupadd.c, src/chage.c,
src/chsh.c: Simplify the PAM error handling. Do not keep the pamh
handle, but terminate the PAM transaction as soon as possible if
there are no PAM session opened.
src/newusers.c, src/pwconv.c, src/chpasswd.c, src/logoutd.c,
src/chfn.c, src/groupmems.c, src/usermod.c, src/pwunconv.c,
src/expiry.c, src/groupdel.c, src/chgpasswd.c, src/useradd.c,
src/su.c, src/groupmod.c, src/passwd.c, src/pwck.c,
src/groupadd.c, src/chage.c, src/login.c, src/grpconv.c,
src/groups.c, src/grpunconv.c, src/chsh.c: Prog is now global (not
static to the file) so that it can be used by the helper functions
of libmisc.
* lib/prototypes.h: Added extern char *Prog.
* libmisc/find_new_gid.c, libmisc/find_new_uid.c: Indicate the
program name with the warning.
* src/chage.c, src/chfn.c, src/chgpasswd.c, src/chpasswd.c,
src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupmems.c,
src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c,
src/passwd.c, src/pwck.c, src/pwconv.c, src/pwunconv.c,
src/useradd.c, src/userdel.c, src/usermod.c: Harmonize the error
message sent to stderr in case of *_update () failure.
* src/chage.c, src/chsh.c, src/groupadd.c, src/passwd.c: Do not
log to syslog when pw_update() or spw_update() fail.
* src/newusers.c: Do not log specific error message to stderr when
sgr_update() fails.
* src/pwconv.c: Remove duplicated definition of Prog.
src/newgrp.c, src/passwd.c, src/su.c: Use the same stderr and
syslog warnings when the username cannot be determined.
* src/newgrp.c: Reuse the same stderr message for groups which do
not exist in the system.
* src/grpconv.c, src/grpunconv.c, src/pwconv.c, src/pwunconv.c,
src/vipw.c: Open syslog with the right identification name.
* src/vipw.c: Log unlock errors to syslog.
* src/vipw.c: Log edits to syslog.
* src/chage.c, src/chfn.c, src/chsh.c, src/gpasswd.c,
src/groupadd.c, src/groupdel.c, src/groupmod.c, src/grpconv.c,
src/grpunconv.c, src/passwd.c, src/pwck.c, src/pwunconv.c,
src/useradd.c, src/usermod.c: Harmonize the syslog levels. Failure
to close or unlock are errors. Failure to open files are warnings.
src/groupadd.c, src/groupdel.c, src/groupmems.c, src/groupmod.c,
src/grpconv.c, src/grpunconv.c, src/newusers.c, src/pwconv.c,
src/pwunconv.c, src/useradd.c, src/userdel.c: Harmonize the name
of the variables keeping the lock status, to match the shadow
library prefixes.
locked. Report failures to unlock to stderr and syslog.
* src/chfn.c: Is case of failure, use fail_exit() rather than
exit().
* src/chfn.c: Ignore the return value of pam_end().
lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h:
Added *_dbname() functions to retrieve the name of the databases.
* lib/groupio.c, lib/groupio.h, lib/pwio.c, lib/pwio.h,
lib/sgroupio.c, lib/sgroupio.h, lib/shadowio.c, lib/shadowio.h:
*_name() functions renamed *setname().
* src/grpck.c, src/pwck.c: Likewise.
* lib/groupio.h, lib/pwio.h, lib/sgroupio.h, lib/shadowio.h: Added
the name of the arguments to the prototypes.
* src/chage, src/chfn.c, src/chgpasswd.c, src/chpasswd.c,
src/chsh.c, src/gpasswd.c, src/groupadd.c, src/groupdel.c,
src/groupmod.c, src/grpck.c, src/grpconv.c, src/grpunconv.c,
src/newusers.c, src/passwd.c, src/pwck.c, src/pwconv.c,
src/pwunconv.c, src/useradd.c, src/userdel.c, src/usermod.c:
Harmonize the erro & syslog messages in case of failure of the
*_lock(), *_open(), *_close(), *_unlock(), *_remove() functions.
* src/chgpasswd.c, src/chpasswd.c, src/usermod.c: Avoid
capitalized messages.
* src/chpasswd.c, src/useradd.c, src/usermod.c: Harmonize messages
in case of inexistent entries.
* src/usermod.c: Harmonize messages in case of already existing
entries.
* src/newusers.c, src/useradd.c: Simplify PAM error handling.
* src/useradd.c: Report failures to unlock files (stderr, syslog,
and audit). But do not fail (continue).
* src/useradd.c (open_files): Do not report to syslog & audit
failures to lock or open the databases. This might be harmless,
and the logs were not already informed that a change was
requested.
* src/usermod.c: It's not the account which is unlocked, but its
password.
src/groupmod.c, src/grpck.c, src/login.c, src/logoutd.c,
src/newgrp.c, src/newusers.c, src/passwd.c, src/pwck.c,
src/suauth.c, src/useradd.c, src/userdel.c, src/usermod.c,
src/vipw.c: Complete the switch from the `' quotation style to ''.
Do it also in SYSLOG messages. Quote some parameters. All this
permits to merge some messages.
* src/chfn.c: Avoid implicit conversion of integers / chars to
booleans.
* src/chfn.c: Ignore return value of setlocale(),
bindtextdomain(), and textdomain().
Files with no license use the default 3-clauses BSD license. The copyright
were mostly not recorded; they were updated according to the Changelog.
"Julianne Frances Haugh and contributors" changed to "copyright holders
and contributors".
src/chfn.c, src/passwd.c, src/chage.c, src/login.c, src/sulogin.c,
src/chsh.c: Fix call to puts (remove end of line, or use fputs).
* po/*.po: Unfuzzy PO files according to above change.
and "pwauth.h" only when compiled without PAM support.
* src/chfn.c, src/chsh.c: Do not include <shadow.h>
* lib/commonio.c: Do not include <shadow.h>. Do not include
<pwd.h>. Include "nscd.h" instead of <nscd.h>.
* configure.in: Do not check if shadow.h exist, but make sure it
exists.
* libmisc/pwdcheck.c, src/chfn.c, src/chsh.c, lib/defines.h,
lib/shadowmem.c, lib/shadowio.c, lib/commonio.c:
HAVE_SHADOW_H is no more needed (shadow.h should always exist).
