Here's a sad story:
* 70971457 is merged into shadow, allowing newgidmap/newuidmap to be
installed with file caps rather than setuid.
* https://bugs.archlinux.org/task/63248 is filed to take advantage of
this.
* The arch maintainer of the 'shadow' package notices that this doesn't
work, and submits a pull request to fix this in shadow.
* edf7547ad5 is merged, fixing the post install hooks.
The problem here is that distros have been building shadow with PAM for
O(years), but the install hooks have silently failed due to the
combination of the directory mismatch (suidubins vs suidsbins) and later
success with setuid'ing newgidmap/newuidmap.
With the install hooks fixed, those of us (Arch[1] and Gentoo[2] so far)
who never built shadow explicitly with --enable-account-tools-setuid are
now getting setuid account tools, and don't have PAM configuration
suitable for use with setuid account management tools.
It's entirely unclear to me why you'd want this, but I assume there's
some reason out there for it existing. Regardless, setuid binaries are
dangerous and shouldn't be enabled by default without good reason.
[1] https://bugs.archlinux.org/task/64836
[2] https://bugs.gentoo.org/702252
With this, it is possible for Linux distributors to store their
supplied default configuration files somewhere below /usr, while
/etc only contains the changes made by the user. The new option
--enable-vendordir defines where the shadow suite should additional
look for login.defs if this file is not in /etc.
libeconf is a key/value configuration file reading library, which
handles the split of configuration files in different locations
and merges them transparently for the application.
A configure error occurs when /bin/sh -> dash:
checking for is_selinux_enabled in -lselinux... yes
checking for semanage_connect in -lsemanage... yes
configure: 16322: test: yesyes: unexpected operator
Use "=" instead of "==" since dash doesn't support this operator.
Signed-off-by: Yi Zhao <yi.zhao@windriver.com>
do not install newuidmap/newgidmap as suid binaries. Running these
tools with the same euid as the owner of the user namespace to
configure requires only CAP_SETUID and CAP_SETGID instead of requiring
CAP_SYS_ADMIN when it is installed as a suid binary.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
if the euid!=owner of the userns, the kernel returns EPERM when trying
to write the uidmap and there is no CAP_SYS_ADMIN in the parent
namespace.
Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.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.
This allows shadow-utils to build on systems like Adélie, which have no
<utmp.h> header or `struct utmp`. We use a <utmpx.h>-based daemon,
utmps[1], which uses `struct utmpx` only.
Tested both `login` and `logoutd` with utmps and both work correctly.
[1]: http://skarnet.org/software/utmps/
Enable the automake feature to produce silent output by default.
When compiling code, we now see things like:
$ make
CC addgrps.o
CC age.o
CC audit_help.o
...
This can be disabled via configure's --disable-silent-rules or
by passing V=1 to make.
Custom output (like in the man subdirs) don't (yet) respect this
feature. More work will be needed to clean those up.
Since xz is fairly common nowadays, and is typically smaller/faster than
bzip2 for people to decompress, switch shadow over too. We also merge
the two init locations into configure.ac to match newer autotools style.
The min automake version is bumped to 1.11 too since that's when xz was
released.
The autoconf/automake guys want AC_INIT to be passed the details of the
package directly rather than going through AM_INIT_AUTOMAKE. Update them
both to use the newer style.
This also allows us to pass in contact details for the project.
We set the minimum autoconf version to 2.64 as that's the first one to
support passing the homepage URL in to AC_INIT. That's a pretty old
release by now, so it shouldn't be a problem.
