[libvirt] new NULL-dereference in qemu_driver.c

Jim Meyering jim at meyering.net
Wed Apr 28 15:43:03 UTC 2010


Chris Lalancette wrote:
> On 04/27/2010 04:40 PM, Jim Meyering wrote:
>> Daniel P. Berrange wrote:
>>
>>> On Tue, Apr 27, 2010 at 06:45:16PM +0200, Jim Meyering wrote:
>>>> I ran clang on the very latest and it spotted this problem:
>>>> >From qemu_driver.c, around line 11100,
>>>>
>>>>     else {
>>>>         /* qemu is a little funny with running guests and the restoration
>>>>          * of snapshots.  If the snapshot was taken online,
>>>>          * then after a "loadvm" monitor command, the VM is set running
>>>>          * again.  If the snapshot was taken offline, then after a "loadvm"
>>>>          * monitor command the VM is left paused.  Unpausing it leads to
>>>>          * the memory state *before* the loadvm with the disk *after* the
>>>>          * loadvm, which obviously is bound to corrupt something.
>>>>          * Therefore we destroy the domain and set it to "off" in this case.
>>>>          */
>>>>
>>>>         if (virDomainObjIsActive(vm)) {
>>>>             qemudShutdownVMDaemon(driver, vm);
>>>>             event = virDomainEventNewFromObj(vm,
>>>>                                              VIR_DOMAIN_EVENT_STOPPED,
>>>>                                              VIR_DOMAIN_EVENT_STOPPED_FROM_SNAPSHOT);
>>>>             if (!vm->persistent) {
>>>>                 if (qemuDomainObjEndJob(vm) > 0)
>>>>                     virDomainRemoveInactive(&driver->domains, vm);
>>>>                 vm = NULL;
>>>
>>> This needs to add 'goto endjob' or possibly 'goto cleanup'
>>
>> No point in endjob, since it does nothing when vm == NULL.
>>
>> Here's a tentative patch for that and another, similar problem
>> (haven't even compiled it or run it through clang, but have to run).
>> Will follow up tomorrow.
>
> Yeah, this looks reasonable and is what I was going to submit.  It
> would be good to give a test first, though.

Can any of you easily test it?
I can't right now.




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