[libvirt] [PATCH 1/1] Fix the crash when seclable is freed

[Li Zhang]

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 at 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 at 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.

>
>> VIR_FREE(def->label);
>> VIR_FREE(def->imagelabel);
>