Re: [PATCH 1/3] xen/swiotlb: fix condition for calling xen_destroy_contiguous_region()

On 4/23/19 6:54 AM, Juergen Gross wrote:

The condition in xen_swiotlb_free_coherent() for deciding whether to call xen_destroy_contiguous_region() is wrong: in case the region to be freed is not contiguous calling xen_destroy_contiguous_region() is the wrong thing to do: it would result in inconsistent mappings of multiple PFNs to the same MFN. This will lead to various strange crashes or data corruption.

Instead of calling xen_destroy_contiguous_region() in that case a warning should be issued as that situation should never occur.

Cc: stable@vger.kernel.org Signed-off-by: Juergen Gross jgross@suse.com

Reviewed-by: Boris Ostrovsky boris.ostrovsky@oracle.com