[libvirt] [PATCH] qemu: fix memory leak in qemuAgentGetFSInfo

Chen Fan chen.fan.fnst at cn.fujitsu.com
Tue Mar 10 09:43:53 UTC 2015


On 03/10/2015 05:32 PM, Ján Tomko wrote:
> On Tue, Mar 10, 2015 at 01:56:11PM +0800, Chen Fan wrote:
>> in virDomainFSInfoFree(), don't free the virDomainFSInfo data.
>>
>> ==10670== 80 bytes in 2 blocks are definitely lost in loss record 576 of 793
>> ==10670==    at 0x4A06BC3: calloc (vg_replace_malloc.c:618)
>> ==10670==    by 0x509DEBD: virAlloc (viralloc.c:144)
>> ==10670==    by 0x19FBD558: qemuAgentGetFSInfo (qemu_agent.c:1837)
>> ==10670==    by 0x1A03CF91: qemuDomainGetFSInfo (qemu_driver.c:19238)
>>
>> Signed-off-by: Chen Fan <chen.fan.fnst at cn.fujitsu.com>
>> ---
>>   src/libvirt-domain.c | 2 ++
>>   1 file changed, 2 insertions(+)
> This does fix the memory leak and makes the function behave like it's
> documented in virDomainGetFSInfo and virDomainFSInfoFree:
> http://libvirt.org/html/libvirt-libvirt-domain.html#virDomainGetFSInfo
> http://libvirt.org/html/libvirt-libvirt-domain.html#virDomainFSInfoFree
>
> But it changes the public API - if there are applications that already
> work around this function by freeing the info, this change would
> introduce a double free.
>
> I would NACK this if the documentation for both APIs didn't say that's
> how this function should behave.
>
> I'd like to hear a second opinion.
I don't think this documentation make any confusable.
for using the function virDomainGetFSInfo(), user also need
to call virDomainFSInfoFree() on each array element, and call free() info.
example:

virDomainFSInfoPtr *info;

ndata = virDomainGetFSInfo(dom, &info, 0);

for (i = 0; i < ndata; i++)
         virDomainFSInfoFree(info[i]);
VIR_FREE(info);

Thanks,
Chen
>
> Jan
>
>> diff --git a/src/libvirt-domain.c b/src/libvirt-domain.c
>> index 04545fd..7f8a7ce 100644
>> --- a/src/libvirt-domain.c
>> +++ b/src/libvirt-domain.c
>> @@ -11337,4 +11337,6 @@ virDomainFSInfoFree(virDomainFSInfoPtr info)
>>       for (i = 0; i < info->ndevAlias; i++)
>>           VIR_FREE(info->devAlias[i]);
>>       VIR_FREE(info->devAlias);
>> +
>> +    VIR_FREE(info);
>>   }
>> -- 
>> 1.9.3
>>
>> --
>> libvir-list mailing list
>> libvir-list at redhat.com
>> https://www.redhat.com/mailman/listinfo/libvir-list





More information about the libvir-list mailing list