[libvirt] [PATCH 02/12] storage: avoid mishandling backing store > 2GB

[Eric Blake]

On 06/07/2011 07:34 AM, Matthias Bolte wrote:
> 2011/6/6 Eric Blake <eblake at redhat.com>:
>> Detected by Coverity.  The code was doing math on shifted unsigned
>> char (which promotes to int), then promoting that to unsigned long
>> during assignment to size.  On 64-bit platforms, this risks sign
>> extending values of size > 2GiB.  Bug present since commit
>> 489fd3 (v0.6.0).

>>
>> +#include <stdint.h>
>>  #ifdef __linux__
>>  # if HAVE_LINUX_MAGIC_H
>>  #  include <linux/magic.h>
>> @@ -274,7 +275,7 @@ qcowXGetBackingStore(char **res,
>>                      bool isQCow2)
>>  {
>>     unsigned long long offset;
>> -    unsigned long size;
>> +    uint32_t size;
>>
>>     *res = NULL;
>>     if (format)
> 
> Using unsigned int instead of uint32_t would also work and avoid
> stdint.h types that the libvirt codebase avoids.

Sure, I'll push with that tweak.

-- 
Eric Blake   eblake at redhat.com    +1-801-349-2682
Libvirt virtualization library http://libvirt.org

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