stable inclusion
from stable-5.10.32
commit f66d695c06f4d788e1ff01778e4e72f8d19474de
bugzilla: 51796

--------------------------------

commit 90929078 upstream.

When mmaping an extra device region verify that the region index
derived from the mmap offset is valid.

Fixes: a15b1883 ("vfio_pci: Allow mapping extra regions")
Cc: stable@vger.kernel.org
Signed-off-by: NChristian A. Ehrhardt <lk@c--e.de>
Message-Id: <20210412214124.GA241759@lisa.in-ulm.de>
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NCornelia Huck <cohuck@redhat.com>
Signed-off-by: NAlex Williamson <alex.williamson@redhat.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>