[libvirt] [PATCH 1/3] qemu: Avoid double free of VM

One of my previous patches (c7ac2519b7f) did try to fix the issue when domain dies too soon during migration. However, this clumsy approach was missing removal of qemuProcessHandleMonitorDestroy resulting in double unrefing of mon->vm and hence producing the daemon crash: ==11843== Invalid read of size 4 ==11843== at 0x50C28C5: virObjectUnref (virobject.c:255) ==11843== by 0x1148F7DB: qemuMonitorDispose (qemu_monitor.c:258) ==11843== by 0x50C2991: virObjectUnref (virobject.c:262) ==11843== by 0x50C2D13: virObjectFreeCallback (virobject.c:388) ==11843== by 0x509C37B: virEventPollCleanupHandles (vireventpoll.c:583) ==11843== by 0x509C711: virEventPollRunOnce (vireventpoll.c:652) ==11843== by 0x509A620: virEventRunDefaultImpl (virevent.c:274) ==11843== by 0x520D21C: virNetServerRun (virnetserver.c:1112) ==11843== by 0x11F368: main (libvirtd.c:1513) ==11843== Address 0x13b88864 is 4 bytes inside a block of size 136 free'd ==11843== at 0x4A07F5C: free (in /usr/lib64/valgrind/vgpreload_memcheck-amd64-linux.so) ==11843== by 0x5079A2F: virFree (viralloc.c:580) ==11843== by 0x50C29E3: virObjectUnref (virobject.c:270) ==11843== by 0x114770E4: qemuProcessHandleMonitorDestroy (qemu_process.c:1103) ==11843== by 0x1148F7CB: qemuMonitorDispose (qemu_monitor.c:257) ==11843== by 0x50C2991: virObjectUnref (virobject.c:262) ==11843== by 0x50C2D13: virObjectFreeCallback (virobject.c:388) ==11843== by 0x509C37B: virEventPollCleanupHandles (vireventpoll.c:583) ==11843== by 0x509C711: virEventPollRunOnce (vireventpoll.c:652) ==11843== by 0x509A620: virEventRunDefaultImpl (virevent.c:274) ==11843== by 0x520D21C: virNetServerRun (virnetserver.c:1112) ==11843== by 0x11F368: main (libvirtd.c:1513) Signed-off-by: Michal Privoznik <mprivozn(a)redhat.com&gt; --- src/qemu/qemu_process.c | 9 --------- 1 file changed, 9 deletions(-) diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c index 7c23eb4..3de4e53 100644 --- a/src/qemu/qemu_process.c +++ b/src/qemu/qemu_process.c @@ -1095,14 +1095,6 @@ error: return -1; } - -static void qemuProcessHandleMonitorDestroy(qemuMonitorPtr mon ATTRIBUTE_UNUSED, - virDomainObjPtr vm, - void *opaque ATTRIBUTE_UNUSED) -{ - virObjectUnref(vm); -} - static int qemuProcessHandleTrayChange(qemuMonitorPtr mon ATTRIBUTE_UNUSED, virDomainObjPtr vm, @@ -1366,7 +1358,6 @@ cleanup: static qemuMonitorCallbacks monitorCallbacks = { - .destroy = qemuProcessHandleMonitorDestroy, .eofNotify = qemuProcessHandleMonitorEOF, .errorNotify = qemuProcessHandleMonitorError, .diskSecretLookup = qemuProcessFindVolumeQcowPassphrase, -- 1.8.1.5