s390/cio: Fix how vfio-ccw checks pinned pages

commit 24abf290 upstream.

We have two nested loops to check the entries within the pfn_array_table
arrays.  But we mistakenly use the outer array as an index in our check,
and completely ignore the indexing performed by the inner loop.

Cc: stable@vger.kernel.org
Signed-off-by: Eric Farman <farman@linux.ibm.com>
Message-Id: <20181002010235.42483-1-farman@linux.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/s390/cio/vfio_ccw_cp.c

@@ -172,7 +172,7 @@ static bool pfn_array_table_iova_pinned(struct pfn_array_table *pat,
 
 	for (i = 0; i < pat->pat_nr; i++, pa++)
 		for (j = 0; j < pa->pa_nr; j++)
-			if (pa->pa_iova_pfn[i] == iova_pfn)
+			if (pa->pa_iova_pfn[j] == iova_pfn)
 				return true;
 
 	return false;