This replaces commit 4d3900f1b7.
The underlying cause of issue #8291 has been fixed, so there is no reason
to paper over it any more.
But it might still be useful not to crash in the face of bad restart data.
That can cause several restarts, or maybe at some point an infinite loop
of restarts. Fail the start (or stop!) request, and write an error to the
system log. Each time reflects a user request where we fail to resume the
display server's access (or revoke it), and it can be useful if the log
shows the most recent one.
FDSTOREREMOVE=1 removes all fds with the specified name. And we had named
the fds after the session. Better fix that.
Closes#8344.
AFAICT there's no point providing compatibility code for this transition.
No-one would be restarting logind on a system with a GUI (where the
session devices are used), because doing so has been killing the GUI, and
even causing startup of the GUI to fail leading to a restart loop.
Upgrading logind on a running system with a GUI might start being possible
after this commit (and after also fixing the display server of your
choice).
Reproducer:
$ meson build && cd build
$ ninja
$ sudo useradd test
$ sudo su test
$ ./systemd --system --test
...
Failed to create /user.slice/user-1000.slice/session-6.scope/init.scope control group: Permission denied
Failed to allocate manager object: Permission denied
Above error message is caused by the fact that user test didn't have its
own session and we tried to set up init.scope already running as user
test in the directory owned by different user.
Let's try to setup cgroup hierarchy, but if that fails return error only
when not running in the test mode.
Fixes#8072
Some versions of asan report the following false positive
when strict_string_checks=1 is passed:
=================================================================
==3297==ERROR: AddressSanitizer: SEGV on unknown address 0x000000000000 (pc 0x7f64e4090286 bp 0x7ffe46acd9a0 sp 0x7ffe46acd118 T0)
==3297==The signal is caused by a READ memory access.
==3297==Hint: address points to the zero page.
#0 0x7f64e4090285 in __strlen_sse2 (/lib64/libc.so.6+0xaa285)
#1 0x7f64e5a51e46 (/lib64/libasan.so.4+0x41e46)
#2 0x7f64e4e5e3a0 (/lib64/libglib-2.0.so.0+0x383a0)
#3 0x7f64e4e5e536 in g_dgettext (/lib64/libglib-2.0.so.0+0x38536)
#4 0x7f64e48fac5f (/lib64/libgio-2.0.so.0+0xc1c5f)
#5 0x7f64e4c03978 in g_type_class_ref (/lib64/libgobject-2.0.so.0+0x30978)
#6 0x7f64e4be9567 in g_object_new_with_properties (/lib64/libgobject-2.0.so.0+0x16567)
#7 0x7f64e4be9fd0 in g_object_new (/lib64/libgobject-2.0.so.0+0x16fd0)
#8 0x7f64e48fd43e in g_dbus_message_new_from_blob (/lib64/libgio-2.0.so.0+0xc443e)
#9 0x564a6aa0de52 in main ../src/libsystemd/sd-bus/test-bus-marshal.c:228
#10 0x7f64e4007009 in __libc_start_main (/lib64/libc.so.6+0x21009)
#11 0x564a6aa0a569 in _start (/home/vagrant/systemd/build/test-bus-marshal+0x5569)
AddressSanitizer can not provide additional info.
SUMMARY: AddressSanitizer: SEGV (/lib64/libc.so.6+0xaa285) in __strlen_sse2
==3297==ABORTING
It's an external library and errors in external libraries are generally not very
useful for looking for internal bugs.
It would be better not to change the code and use standard suppression
techinques decribed at
https://clang.llvm.org/docs/AddressSanitizer.html#suppressing-reports-in-external-libraries,
but, unfortunaley, none of them seems to be able to suppress fatal errors in asan intself.
This mainly gets around a kernel bug making it possible to
have non-existent paths in /proc/self/mountinfo, but it should also
prevent flaky failures that can happen if something changes immediately
after or during reading /proc/self/mountinfo.
Closes https://github.com/systemd/systemd/issues/8286.
meson.build:2907: WARNING: Trying to compare values of different types (bool, str) using ==.
The result of this is undefined and will become a hard error in a future Meson release.
Otherwise having a .socket unit start a .service running a binary under
a chroot fails as the unit is unable to determine the SELinux label of
the binary.
We already don't allow directly opening block devices attached to the seat.
They are handled by udisks instead. Clarify the code used when restarting
logind.
We're not removing the pushed fd "again"; this is the only place
logind removes it from PID1. (And stopping the fd doesn't always
cause PID1 to remove the fd itself; it depends on the device type).
Suspend to Hibernate is a new sleep method that invokes suspend
for a predefined period of time before automatically waking up
and hibernating the system.
It's similar to HybridSleep however there isn't a performance
impact on every suspend cycle.
It's intended to use with systems that may have a higher power
drain in their supported suspend states to prevent battery and
data loss over an extended suspend cycle.
Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Reproducer:
$ meson build && cd build
$ ninja
$ sudo useradd test
$ sudo su test
$ ./systemd --system --test
...
Failed to create /user.slice/user-1000.slice/session-6.scope/init.scope control group: Permission denied
Failed to allocate manager object: Permission denied
Above error message is caused by the fact that user test didn't have its
own session and we tried to set up init.scope already running as user
test in the directory owned by different user.
Let's skip setting up init.scope altogether since we won't be launching
processes anyway.
We don't need to check if we are adding ourselves to the list
if we know that it's the windows or EFI shell loaders.
If we are adding the EFI default loader, additionally try to
see if we can find the systemd-boot magic string and skip
this entry if we do.
ISO C does not allow empty statements outside of functions, and gcc
will warn the trailing semicolons when compiling with -pedantic:
warning: ISO C does not allow extra ‘;’ outside of a function [-Wpedantic]
But our code cannot compile with -pedantic anyway, at least because
warning: ISO C does not support ‘__PRETTY_FUNCTION__’ predefined identifier [-Wpedantic]
Without -pedatnic, clang and even old gcc (3.4) generate no warnings about
those semicolons, so let's just drop __useless_struct_to_allow_trailing_semicolon__.
This should make it a bit easier to search for real file descriptor leaks.
```
$ valgrind --leak-check=full --track-fds=yes ./build/test-fileio
...
==29457==
==29457== FILE DESCRIPTORS: 4 open at exit.
==29457== Open file descriptor 3: /tmp/test-systemd_writing_tmpfile.lyV5Rc
==29457== at 0x4B9AD9E: open (open.c:43)
==29457== by 0x4B19B24: __gen_tempname (tempname.c:261)
==29457== by 0x4BA5CC3: mkostemp64 (mkostemp64.c:32)
==29457== by 0x48F739B: mkostemp_safe (fileio.c:1206)
==29457== by 0x10D968: test_writing_tmpfile (test-fileio.c:620)
==29457== by 0x10E930: main (test-fileio.c:767)
==29457==
```
This helps get around a bug confusing `glibc` and making the test bail
out with the following error under `asan` on `x86`:
Fatal error: glibc detected an invalid stdio handle
Aborted (core dumped)
The bug has been reported in https://github.com/google/sanitizers/issues/778,
but it is unlikely to be fixed anytime soon.
Otherwise we can be fooled if one path component is replaced underneath us.
The patch achieves that by always operating at file descriptor level (by using
*at() helpers) and by making sure we do not any path resolution when traversing
direcotry trees.
However this is not always possible, for instance when listing the content of a
directory or some operations don't provide the *at() helpers or others (such as
fchmodat()) don't have the AT_EMPTY_PATH flag. In such cases we operate on
/proc/self/fd/%i pseudo-symlink instead, which works the same for all kinds of
objects and requires no checking of type beforehand.
Also O_PATH flag is used when opening file objects in order to prevent
undesired behaviors: device nodes from reacting, automounts from
triggering, etc...
Fixes: #7986
Fixes: CVE-2018-6954
Zbigniew Jędrzejewski-Szmek
Alan Jenkins
Michal Sekletar
Michal Koutný
Evegeny Vereshchagin
Filipe Brandenburger
Yu Watanabe
Peter Hutterer
Lennart Poettering
Mario Limonciello
Daniel Lin
Jan Janssen
Tomasz Torcz
Franck Bui