[evolution-data-server] Bug 656635 - Use-after-free when setting summary for component with alarms

[Milan Crha <mcrha src gnome org>]

commit 98320987125ae337e59786eea6cd0da084ce96d6
Author: Milan Crha <mcrha redhat com>
Date:   Wed Apr 12 12:21:02 2017 +0200

    Bug 656635 - Use-after-free when setting summary for component with alarms

 src/calendar/libecal/e-cal-component.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/src/calendar/libecal/e-cal-component.c b/src/calendar/libecal/e-cal-component.c
index 403d400..65b530d 100644
--- a/src/calendar/libecal/e-cal-component.c
+++ b/src/calendar/libecal/e-cal-component.c
@@ -4469,7 +4469,7 @@ e_cal_component_get_summary (ECalComponent *comp,
 }
 
 typedef struct {
-       const gchar *old_summary;
+       gchar *old_summary;
        const gchar *new_summary;
 } SetAlarmDescriptionData;
 
@@ -4560,7 +4560,8 @@ e_cal_component_set_summary (ECalComponent *comp,
        g_return_if_fail (summary->value != NULL);
 
        if (priv->summary.prop) {
-               sadd.old_summary = icalproperty_get_summary (priv->summary.prop);
+               /* Make a copy, to avoid use-after-free */
+               sadd.old_summary = g_strdup (icalproperty_get_summary (priv->summary.prop));
                icalproperty_set_summary (priv->summary.prop, (gchar *) summary->value);
        } else {
                sadd.old_summary = NULL;
@@ -4590,6 +4591,8 @@ e_cal_component_set_summary (ECalComponent *comp,
        /* look for alarms that need a description */
        sadd.new_summary = summary->value;
        g_hash_table_foreach (priv->alarm_uid_hash, set_alarm_description_cb, &sadd);
+
+       g_free (sadd.old_summary);
 }
 
 /**