From 52df8972d4005b23f7c2e52b0cf7210b8c594876 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Mon, 25 Jun 2018 14:29:25 +0200
Subject: [PATCH] timedate: use gmtime_r() and localtime_r()

gmtime() and localtime() operate on a static buffer. let's avoid this,
as we never know whether some library might use these calls in some
backrgound thread.

Discovered by lgtm:

https://lgtm.com/projects/g/systemd/systemd/
(cherry picked from commit e46acb7950a9f07ac60d772309de842c444ad2bd)

Resolves: #1694605
---
 src/timedate/timedated.c | 20 ++++++++++----------
 1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/src/timedate/timedated.c b/src/timedate/timedated.c
index 09d0dbabcd..afd54a8936 100644
--- a/src/timedate/timedated.c
+++ b/src/timedate/timedated.c
@@ -542,9 +542,9 @@ static int method_set_local_rtc(sd_bus *bus, sd_bus_message *m, void *userdata,
                  * initialize the timezone fields of
                  * struct tm. */
                 if (c->local_rtc)
-                        tm = *localtime(&ts.tv_sec);
+                        localtime_r(&ts.tv_sec, &tm);
                 else
-                        tm = *gmtime(&ts.tv_sec);
+                        gmtime_r(&ts.tv_sec, &tm);
 
                 /* Override the main fields of
                  * struct tm, but not the timezone
@@ -562,15 +562,15 @@ static int method_set_local_rtc(sd_bus *bus, sd_bus_message *m, void *userdata,
                 }
 
         } else {
-                struct tm *tm;
+                struct tm tm;
 
                 /* Sync RTC from system clock */
                 if (c->local_rtc)
-                        tm = localtime(&ts.tv_sec);
+                        localtime_r(&ts.tv_sec, &tm);
                 else
-                        tm = gmtime(&ts.tv_sec);
+                        gmtime_r(&ts.tv_sec, &tm);
 
-                clock_set_hwclock(tm);
+                clock_set_hwclock(&tm);
         }
 
         log_info("RTC configured to %s time.", c->local_rtc ? "local" : "UTC");
@@ -585,7 +585,7 @@ static int method_set_time(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bu
         Context *c = userdata;
         int64_t utc;
         struct timespec ts;
-        struct tm* tm;
+        struct tm tm;
         int r;
 
         assert(bus);
@@ -633,10 +633,10 @@ static int method_set_time(sd_bus *bus, sd_bus_message *m, void *userdata, sd_bu
 
         /* Sync down to RTC */
         if (c->local_rtc)
-                tm = localtime(&ts.tv_sec);
+                localtime_r(&ts.tv_sec, &tm);
         else
-                tm = gmtime(&ts.tv_sec);
-        clock_set_hwclock(tm);
+                gmtime_r(&ts.tv_sec, &tm);
+        clock_set_hwclock(&tm);
 
         log_struct(LOG_INFO,
                    LOG_MESSAGE_ID(SD_MESSAGE_TIME_CHANGE),