Hi,
Diego Nicola Barbato <dnbarb...@posteo.de> skribis:
> XLockMore (as invoked by the command `xlock') displays the wrong time on
> the lock screen. Instead of honouring the timezone set in `config.scm'
> (as do other programs e.g. the `date' command) it displays UTC.
The problem is that setuid programs ignore $TZDIR; quoth ‘tzfile.c’ in
libc:
/* We must not allow to read an arbitrary file in a setuid
program. So we fail for any file which is not in the
directory hierachy starting at TZDIR
and which is not the system wide default TZDEFAULT. */
if (__libc_enable_secure
&& ((*file == '/'
&& memcmp (file, TZDEFAULT, sizeof TZDEFAULT)
&& memcmp (file, default_tzdir, sizeof (default_tzdir) - 1))
|| strstr (file, "../") != NULL))
/* This test is certainly a bit too restrictive but it should
catch all critical cases. */
goto ret_free_transitions;
Thus, if I set TZ=Europe/Paris, I see that setuid binaries look for
timezone data only under
/gnu/store/3h31zsqxjjg52da5gp3qmhkh4x8klhah-glibc-2.25/share/zoneinfo/Europe/Paris,
which doesn’t exist.
Since GuixSD provides /etc/localtime already, we can actually unset TZ.
And when we do so, setuid binaries simply honor /etc/localtime and don’t
go searching for timezone data elsewhere, and they see the right time.
Can you confirm that:
(unset TZ; xlock)
works for you?
I’ll commit the patch below if it does.
Thanks,
Ludo’.
diff --git a/gnu/system.scm b/gnu/system.scm
index 5f562b48b..ce2c05f4e 100644
--- a/gnu/system.scm
+++ b/gnu/system.scm
@@ -727,7 +727,8 @@ use 'plain-file' instead~%")
"Return the environment variables of OS for
@var{session-environment-service-type}, to be used in @file{/etc/environment}."
`(("LANG" . ,(operating-system-locale os))
- ("TZ" . ,(operating-system-timezone os))
+ ;; Note: No need to set 'TZ' since (1) we provide /etc/localtime, and (2)
+ ;; it doesn't work for setuid binaries. See <https://bugs.gnu.org/29212>.
("TZDIR" . ,(file-append tzdata "/share/zoneinfo"))
;; Tell 'modprobe' & co. where to look for modules.
("LINUX_MODULE_DIRECTORY" . "/run/booted-system/kernel/lib/modules")
