libvirt/src/util/virdbus.h
Michal Privoznik 862298a2e7 dbus: Don't unref NULL messages
Apparently we are not the only ones with dumb free functions
because dbus_message_unref() does not accept NULL either. But if
I were to vote, this one is even more evil. Instead of returning
an error just like we do it immediately dereference any pointer
passed and thus crash you app. Well done DBus!

  Program received signal SIGSEGV, Segmentation fault.
  [Switching to Thread 0x7f878ebda700 (LWP 31264)]
  0x00007f87be4016e5 in ?? () from /usr/lib64/libdbus-1.so.3
  (gdb) bt
  #0  0x00007f87be4016e5 in ?? () from /usr/lib64/libdbus-1.so.3
  #1  0x00007f87be3f004e in dbus_message_unref () from /usr/lib64/libdbus-1.so.3
  #2  0x00007f87bf6ecf95 in virSystemdGetMachineNameByPID (pid=9849) at util/virsystemd.c:228
  #3  0x00007f879761bd4d in qemuConnectCgroup (driver=0x7f87600a32a0, vm=0x7f87600c7550) at qemu/qemu_cgroup.c:909
  #4  0x00007f87976386b7 in qemuProcessReconnect (opaque=0x7f87600db840) at qemu/qemu_process.c:3386
  #5  0x00007f87bf6edfff in virThreadHelper (data=0x7f87600d5580) at util/virthread.c:206
  #6  0x00007f87bb602334 in start_thread (arg=0x7f878ebda700) at pthread_create.c:333
  #7  0x00007f87bb3481bd in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:109
  (gdb) frame 2
  #2  0x00007f87bf6ecf95 in virSystemdGetMachineNameByPID (pid=9849) at util/virsystemd.c:228
  228         dbus_message_unref(reply);
  (gdb) p reply
  $1 = (DBusMessage *) 0x0

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2016-02-11 11:35:02 +01:00

79 lines
2.6 KiB
C

/*
* virdbus.h: helper for using DBus
*
* Copyright (C) 2012-2013 Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library. If not, see
* <http://www.gnu.org/licenses/>.
*
*/
#ifndef __VIR_DBUS_H__
# define __VIR_DBUS_H__
# ifdef WITH_DBUS
# undef interface /* Work around namespace pollution in mingw's rpc.h */
# include <dbus/dbus.h>
# else
# define DBusConnection void
# define DBusMessage void
# endif
# include "internal.h"
# include <stdarg.h>
void virDBusSetSharedBus(bool shared);
DBusConnection *virDBusGetSystemBus(void);
bool virDBusHasSystemBus(void);
void virDBusCloseSystemBus(void);
DBusConnection *virDBusGetSessionBus(void);
int virDBusCreateMethod(DBusMessage **call,
const char *destination,
const char *path,
const char *iface,
const char *member,
const char *types, ...);
int virDBusCreateMethodV(DBusMessage **call,
const char *destination,
const char *path,
const char *iface,
const char *member,
const char *types,
va_list args);
int virDBusCreateReply(DBusMessage **reply,
const char *types, ...);
int virDBusCreateReplyV(DBusMessage **reply,
const char *types,
va_list args);
int virDBusCallMethod(DBusConnection *conn,
DBusMessage **reply,
virErrorPtr error,
const char *destination,
const char *path,
const char *iface,
const char *member,
const char *types, ...);
int virDBusMessageRead(DBusMessage *msg,
const char *types, ...);
void virDBusMessageUnref(DBusMessage *msg);
int virDBusIsServiceEnabled(const char *name);
int virDBusIsServiceRegistered(const char *name);
bool virDBusErrorIsUnknownMethod(virErrorPtr err);
#endif /* __VIR_DBUS_H__ */