4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> [ Upstream commit 951a010233625b77cde3430b4b8785a9a22968d1 ] If the requested range has a hole, the calculation of the number of pages to unmap is off by one. Fix it. Signed-off-by: Ross Lagerwall <ross.lagerwall@xxxxxxxxxx> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/xen/gntdev.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) --- a/drivers/xen/gntdev.c +++ b/drivers/xen/gntdev.c @@ -378,10 +378,8 @@ static int unmap_grant_pages(struct gran } range = 0; while (range < pages) { - if (map->unmap_ops[offset+range].handle == -1) { - range--; + if (map->unmap_ops[offset+range].handle == -1) break; - } range++; } err = __unmap_grant_pages(map, offset, range);