soc: aspeed: lpc-ctrl: Fix boundary check for mmap

stable inclusion
from linux-4.19.207
commit 9c8891b638319ddba9cfa330247922cd960c95b0
CVE: CVE-2021-42252

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

commit b49a0e69 upstream.

The check mixes pages (vm_pgoff) with bytes (vm_start, vm_end) on one
side of the comparison, and uses resource address (rather than just the
resource size) on the other side of the comparison.
This can allow malicious userspace to easily bypass the boundary check and
map pages that are located outside memory-region reserved by the driver.

Fixes: 6c4e9767 ("drivers/misc: Add Aspeed LPC control driver")
Cc: stable@vger.kernel.org
Signed-off-by: Iwona Winiarska <iwona.winiarska@intel.com>
Reviewed-by: Andrew Jeffery <andrew@aj.id.au>
Tested-by: Andrew Jeffery <andrew@aj.id.au>
Reviewed-by: Joel Stanley <joel@aj.id.au>
Signed-off-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>