On Tue, Mar 26, 2013 at 04:13:58PM +0300, Dan Carpenter wrote:
> The worry here is that a large value of hdr.start would cause a
> read before the start of the array and a crash in
> vfio_msi_set_vector_signal().
>
> The check in vfio_msi_set_block() is not enough:
>
> if (start + count > vdev->num_ctx)
> return -EINVAL;
>
> A large value of "start" would lead to an integer overflow.
>
> The check in vfio_msi_set_vector_signal() doesn't work either:
>
> if (vector >= vdev->num_ctx)
> return -EINVAL;
>
> Here "vector" is "count" casted to a signed int so it would be negative
^^^^^
I meant "start" not "count".
> and thus smaller than "vdev->num_ctx" which is also a signed int.
>
Gar... I hate this patch already. I really should make
vdev->num_ctx an unsigned int. I'll send that in a v2 along with
whatever other suggestions people send.
regards,
dan carpenter
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