Re: [libvirt] [PATCH 1/1] Fix the crash when seclable is freed
On 02/04/13 16:04, Li Zhang wrote:
On 2013年04月02日 15:03, Li Zhang wrote:
> On 2013年04月02日 14:47, Osier Yang wrote:
>> On 02/04/13 13:58, Li Zhang wrote:
>>> From: Li Zhang <zhlcindy(a)linux.vnet.ibm.com>
>>>
>>> When seclabel's type is VIR_DOMAIN_SECLABEL_NONE,
>>> virSecurityLabelDefPtr's members are not allocated.
>>> So it will cause crash when calling VIR_FREE.
>>>
>>> This problem is found when running autotest on PPC.
>>>
>>> Failed to remove cgroup for virt-tests-vm1
>>> *** glibc detected *** /usr/sbin/libvirtd: free(): invalid pointer:
>>> 0x00003fff9c187510 ***
>>> ======= Backtrace: =========
>>> /lib64/libc.so.6(+0xb89c4)[0x3fffa9bc89c4]
>>> /lib64/libvirt.so.0(virFree-0x3e2320)[0x3fffaa82e9c0]
>>> /lib64/libvirt.so.0(virSecurityLabelDefFree-0x378984)[0x3fffaa89d69c]
>>> /lib64/libvirt.so.0(virDomainDefFree-0x367c98)[0x3fffaa8ae968]
>>>
/usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so(qemuProcessStop-0xc85f8)[0x3fffa2899d58]
>>>
>>>
/usr/lib64/libvirt/connection-driver/libvirt_driver_qemu.so(+0xc3668)[0x3fffa28e3668]
>>>
>>> /lib64/libvirt.so.0(virDomainDestroy-0x309bd0)[0x3fffaa90f6f0]
>>> /usr/sbin/libvirtd[0x10035230]
>>> /lib64/libvirt.so.0(virNetServerProgramDispatch-0x289b50)[0x3fffaa995930]
>>>
>>> /lib64/libvirt.so.0(+0x20db18)[0x3fffaa98db18]
>>> /lib64/libvirt.so.0(+0xfbd24)[0x3fffaa87bd24]
>>> /lib64/libvirt.so.0(+0xfaec8)[0x3fffaa87aec8]
>>> /lib64/libpthread.so.0(+0xc604)[0x3fffa9d7c604]
>>> /lib64/libc.so.6(clone-0xb8fe4)[0x3fffa9c3f094]
>>>
>>> Signed-off-by: Li Zhang <zhlcindy(a)linux.vnet.ibm.com>
>>> ---
>>> src/conf/domain_conf.c | 2 ++
>>> 1 files changed, 2 insertions(+), 0 deletions(-)
>>>
>>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
>>> index f3fca7f..2856660 100644
>>> --- a/src/conf/domain_conf.c
>>> +++ b/src/conf/domain_conf.c
>>> @@ -1006,6 +1006,8 @@
>>> virSecurityLabelDefFree(virSecurityLabelDefPtr def)
>>> {
>>> if (!def)
>>> return;
>>> + if (def->type == VIR_DOMAIN_SECLABEL_NONE)
>>> + return;
>>> VIR_FREE(def->model);
>>
>> model is always parsed. So it will be leaked if someone specifies
>> "model" even the type is "none".
> Okay, it seems that is not always non-NULL although it is always parsed.
>
> My XML file is as:
> <seclabel type='none'/>
>
> It should be better to add if clause before VIR_FREE.
>
Sorry, it seems that this is not right solution to resolve the problem.
free(ptr): ptr can be NULL.
This root cause is because of invalid pointer which is not NULL.
I need to find out the invalid pointer.
The solution is not to parse "model" when the seclabel type is
"none".
I might not be 100% correct. But I think the "model" is just useless
for "none". Then your patch is right.
>>
>>> VIR_FREE(def->label);
>>> VIR_FREE(def->imagelabel);
>>
>