AuroraMiddleware/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2024-12-02 17:50:20 +00:00
Code Issues Packages Projects Releases Wiki Activity

timezone: handle truncated timezones from tzcode-2021d and later (BZ #28707)

Browse Source 
When using a timezone file with a truncated starting time,
generated by the zic in IANA tzcode-2021d a.k.a. tzlib-2021d
(also in tzlib-2021e; current as of this writing), glibc
asserts in __tzfile_read (on e.g. tzset() for this file) and
you may find lines matching "tzfile.c:435: __tzfile_read:
Assertion `num_types == 1' failed" in your syslog.

One example of such a file is the tzfile for Asuncion
generated by tzlib-2021e as follows, using the tzlib-2021e zic:
"zic -d DEST -r @1546300800 -L /dev/null -b slim
SOURCE/southamerica".  Note that in its type 2 header, it has
two entries in its "time-types" array (types), but only one
entry in its "transition types" array (type_idxs).

This is valid and expected already in the published RFC8536, and
not even frowned upon: "Local time for timestamps before the
first transition is specified by the first time type (time type
0)" ... "every nonzero local time type index SHOULD appear at
least once in the transition type array".  Note the "nonzero ...
index".  Until the 2021d zic, index 0 has been shared by the
first valid transition but with 2021d it's separate, set apart
as a placeholder and only "implicitly" indexed.  (A draft update
of the RFC mandates that the entry at index 0 is a placeholder
in this case, hence can no longer be shared.)

	* time/tzfile.c (__tzfile_read): Don't assert when no transitions
	are found.

Co-authored-by: Christopher Wong <Christopher.Wong@axis.com>
(cherry picked from commit c36f64aa6d)
This commit is contained in:
Hans-Peter Nilsson 2021-12-17 21:38:00 +01:00 committed by Florian Weimer
parent 515a6f53cd
commit 85b24f9694
2 changed files with 3 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
NEWS
View File

@ -28,6 +28,7 @@ The following bugs are resolved with this release:
[28702] RISC-V: clone does not align stack
[28703] RISC-V: _dl_init might be called with unaligned stack
[28704] elf/tst-cpu-features-cpuinfo fails for KVM guests on some AMD systems
[28707] assert in tzfile.c __tzfile_read striking with truncated timezones
[28744] A64FX string functions are selected without SVE HWCAP

4
time/tzfile.c
View File

@ -431,8 +431,8 @@ __tzfile_read (const char *file, size_t extra, char **extrap)
if (__tzname[0] == NULL)
{
/* This should only happen if there are no transition rules.
In this case there should be only one single type. */
assert (num_types == 1);
In this case there's usually only one single type, unless
e.g. the data file has a truncated time-range. */
__tzname[0] = __tzstring (zone_names);
}
if (__tzname[1] == NULL)