[libvirt] [PATCH libvirt] libxl: avoid freeing an uninitialised bitmap

Jim Fehlig jfehlig at suse.com
Fri Jun 19 19:20:34 UTC 2015


On 06/19/2015 10:54 AM, Eric Blake wrote:
> On 06/19/2015 10:33 AM, Ian Campbell wrote:
>> If vm->def->cputune.nvcpupin is 0 in libxlDomainSetVcpuAffinities (as
>> seems to be the case on arm) then the VIR_FREE after cleanup: would be
>> operating on an uninitialised pointer in map.map.
>>
>> Fix this by using libxl_bitmap_init and libxl_bitmap_dispose in the
>> appropriate places (like VIR_FREE libxl_bitmap_dispose is also
> s/VIR_FREE/VIR_FREE,/
>
>> idempotent, so there is no double free on exit from the loop).
>>
>> libxl_bitmap_dispose is slightly preferable since it also sets
>> map.size back to 0, avoiding a potential source of confusion.
>>
>> This fixes the crashes we've been seeing in the Xen automated tests on
>> ARM.
>>
>> I had a glance at the handful of other users of libxl_bitmap and none
>> of them looked to have a similar issue.
>>
>> Signed-off-by: Ian Campbell <ian.campbell at citrix.com>
>> ---
>>   src/libxl/libxl_domain.c |    6 ++++--
>>   1 file changed, 4 insertions(+), 2 deletions(-)
> ACK.

Modified the commit message as suggested and pushed.  Thanks!

Regards,
Jim




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