https://bugzilla.redhat.com/show_bug.cgi?id=866524 Since the virConnect object is not locked wholely when doing virConenctDispose, a thread can get the lock and thus might cause the race. Detected by valgrind: ==23687== Invalid read of size 4 ==23687== at 0x38BAA091EC: pthread_mutex_lock (pthread_mutex_lock.c:61) ==23687== by 0x3FBA919E36: remoteClientCloseFunc (remote_driver.c:337) ==23687== by 0x3FBA936BF2: virNetClientCloseLocked (virnetclient.c:688) ==23687== by 0x3FBA9390D8: virNetClientIncomingEvent (virnetclient.c:1859) ==23687== by 0x3FBA851AAE: virEventPollRunOnce (event_poll.c:485) ==23687== by 0x3FBA850846: virEventRunDefaultImpl (event.c:247) ==23687== by 0x40CD61: vshEventLoop (virsh.c:2128) ==23687== by 0x3FBA8626F8: virThreadHelper (threads-pthread.c:161) ==23687== by 0x38BAA077F0: start_thread (pthread_create.c:301) ==23687== by 0x33F68E570C: clone (clone.S:115) ==23687== Address 0x4ca94e0 is 144 bytes inside a block of size 312 free'd ==23687== at 0x4A0595D: free (vg_replace_malloc.c:366) ==23687== by 0x3FBA8588B8: virFree (memory.c:309) ==23687== by 0x3FBA86AAFC: virObjectUnref (virobject.c:145) ==23687== by 0x3FBA8EA767: virConnectClose (libvirt.c:1458) ==23687== by 0x40C8B8: vshDeinit (virsh.c:2584) ==23687== by 0x41071E: main (virsh.c:3022) The above race is caused by the eventLoop thread tries to handle the net client event by calling the callback set by: virNetClientSetCloseCallback(priv->client, remoteClientCloseFunc, conn, NULL); I.E. remoteClientCloseFunc, which lock/unlock the virConnect object. This patch is to fix it by locking the whole virConnect object when disposing it. --- src/datatypes.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/src/datatypes.c b/src/datatypes.c index c0ed3a2..8648ecb 100644 --- a/src/datatypes.c +++ b/src/datatypes.c @@ -128,6 +128,8 @@ virConnectDispose(void *obj) { virConnectPtr conn = obj; + virMutexLock(&conn->lock); + if (conn->networkDriver) conn->networkDriver->close(conn); if (conn->interfaceDriver) @@ -143,8 +145,6 @@ virConnectDispose(void *obj) if (conn->driver) conn->driver->close(conn); - virMutexLock(&conn->lock); - if (conn->closeFreeCallback) conn->closeFreeCallback(conn->closeOpaque); -- 1.7.7.6 -- libvir-list mailing list libvir-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/libvir-list