On 03/22/2011 08:02 PM, Wen Congyang wrote:
Steps to reproduce this bug: # cat usb.xml <hostdev mode='subsystem' type='usb'> <source> <address bus='0x001' device='0x003'/> </source> </hostdev> # virsh attach-device vm1 usb.xml error: Failed to attach device from usb.xml error: server closed connection:
The reason of this bug is that we set data.cgroup to NULL, and this will cause libvirtd crashed.
usbDevice *usb; - qemuCgroupData data = { vm, cgroup }; + qemuCgroupData data;
if (virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) !=0 ) { qemuReportError(VIR_ERR_INTERNAL_ERROR, @@ -873,6 +873,8 @@ int qemuDomainAttachHostUsbDevice(struct qemud_driver *driver, hostdev->source.subsys.u.usb.device)) == NULL) goto error;
+ data.vm = vm; + data.cgroup = cgroup;
ACK. Latent bug introduced in commit b4d3434f, exposed by commit f2512684. (That explains why I didn't see it - when I tested b4d3434f, nothing dereferenced the NULL, and my testing of f2512684 wasn't as thorough). -- Eric Blake eblake@redhat.com +1-801-349-2682 Libvirt virtualization library http://libvirt.org