[libvirt] [PATCH] conf: fix crash when match a network iscsi hostdev with a host iscsi hostdev

[Luyao Huang]

On 12/15/2014 07:58 PM, John Ferlan wrote:
>
> On 12/14/2014 10:09 PM, Luyao Huang wrote:
>> https://bugzilla.redhat.com/show_bug.cgi?id=1174053
>>
>> When we use attach-device to coldplug a network iscsi hostdev,
>> libvirt will check if there is already a device in XML. But if
>> the 'b' is a host iscsi hostdev and 'a' is a network iscsi hostdev
>> , libvirtd will crash in virDomainHostdevMatchSubsysSCSIiSCSI,
>> because 'b' doesn't have a hostname.
>>
>> Add a check in virDomainHostdevMatchSubsys, if the a's protocol
>> and b's protocol is not the same.
>>
>> backtrace like this:
>>
>> 0  0x00007f850d6bc307 in virDomainHostdevMatchSubsysSCSIiSCSI at conf/domain_conf.c:10889
>> 1  virDomainHostdevMatchSubsys at conf/domain_conf.c:10911
>> 2  virDomainHostdevMatch at conf/domain_conf.c:10973
>> 3  virDomainHostdevFind at conf/domain_conf.c:10998
>> 4  0x00007f84f6a10560 in qemuDomainAttachDeviceConfig at qemu/qemu_driver.c:7223
>> 5  qemuDomainAttachDeviceFlags at qemu/qemu_driver.c:7554
>>
>> Signed-off-by: Luyao Huang <lhuang at redhat.com>
>> ---
>>   src/conf/domain_conf.c | 4 +++-
>>   1 file changed, 3 insertions(+), 1 deletion(-)
>>
>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>> index 5cf0b1a..eb63c93 100644
>> --- a/src/conf/domain_conf.c
>> +++ b/src/conf/domain_conf.c
>> @@ -11184,7 +11184,9 @@ static int
>>   virDomainHostdevMatchSubsys(virDomainHostdevDefPtr a,
>>                               virDomainHostdevDefPtr b)
>>   {
>> -    if (a->source.subsys.type != b->source.subsys.type)
>> +    if (a->source.subsys.type != b->source.subsys.type ||
>> +        (a->source.subsys.type == VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_SCSI &&
>> +         a->source.subsys.u.scsi.protocol != b->source.subsys.u.scsi.protocol))
> While the check works - it's in the wrong place. It should be in the
> subsequent switch.  I'll clean it up a bit and also reference the commit
> id that introduced the issue as part of the commit message
Thanks a lot for your help and i will try to fix in a right place next 
time :)
> John
>
>>           return 0;
>>   
>>       switch (a->source.subsys.type) {
>>
Luyao