On Tue, Jun 28 2022, Alex Williamson <alex.williamson@xxxxxxxxxx> wrote:
> On Tue, 28 Jun 2022 23:24:29 +0800
> Schspa Shi <schspa@xxxxxxxxx> wrote:
>
>> API vfio_info_cap_add will free caps->buf, clear it to NULL after
>> free.
>
> Should this be something like:
>
> On buffer resize failure, vfio_info_cap_add() will free the buffer,
> report zero for the size, and return -ENOMEM. As additional
> hardening, also clear the buffer pointer to prevent any chance of a
> double free.
I like that better. With that,
Reviewed-by: Cornelia Huck <cohuck@xxxxxxxxxx>
>
> Thanks,
> Alex
>
>> Signed-off-by: Schspa Shi <schspa@xxxxxxxxx>
>> ---
>> drivers/vfio/vfio.c | 1 +
>> 1 file changed, 1 insertion(+)
>>
>> diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
>> index 61e71c1154be..a0fb93866f61 100644
>> --- a/drivers/vfio/vfio.c
>> +++ b/drivers/vfio/vfio.c
>> @@ -1812,6 +1812,7 @@ struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
>> buf = krealloc(caps->buf, caps->size + size, GFP_KERNEL);
>> if (!buf) {
>> kfree(caps->buf);
>> + caps->buf = NULL;
>> caps->size = 0;
>> return ERR_PTR(-ENOMEM);
>> }
