From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:47998 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752109AbdFLMux (ORCPT ); Mon, 12 Jun 2017 08:50:53 -0400 Subject: Patch "drivers: char: mem: Fix wraparound check to allow mappings up to the end" has been added to the 4.9-stable tree To: jwerner@chromium.org, gregkh@linuxfoundation.org, nico.h@gmx.de Cc: , From: Date: Mon, 12 Jun 2017 14:50:43 +0200 Message-ID: <14972718429153@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled drivers: char: mem: Fix wraparound check to allow mappings up to the end to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drivers-char-mem-fix-wraparound-check-to-allow-mappings-up-to-the-end.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 32829da54d9368103a2f03269a5120aa9ee4d5da Mon Sep 17 00:00:00 2001 From: Julius Werner Date: Fri, 2 Jun 2017 15:36:39 -0700 Subject: drivers: char: mem: Fix wraparound check to allow mappings up to the end From: Julius Werner commit 32829da54d9368103a2f03269a5120aa9ee4d5da upstream. A recent fix to /dev/mem prevents mappings from wrapping around the end of physical address space. However, the check was written in a way that also prevents a mapping reaching just up to the end of physical address space, which may be a valid use case (especially on 32-bit systems). This patch fixes it by checking the last mapped address (instead of the first address behind that) for overflow. Fixes: b299cde245 ("drivers: char: mem: Check for address space wraparound with mmap()") Reported-by: Nico Huber Signed-off-by: Julius Werner Signed-off-by: Greg Kroah-Hartman --- drivers/char/mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -343,7 +343,7 @@ static int mmap_mem(struct file *file, s phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; /* It's illegal to wrap around the end of the physical address space. */ - if (offset + (phys_addr_t)size < offset) + if (offset + (phys_addr_t)size - 1 < offset) return -EINVAL; if (!valid_mmap_phys_addr_range(vma->vm_pgoff, size)) Patches currently in stable-queue which might be from jwerner@chromium.org are queue-4.9/drivers-char-mem-fix-wraparound-check-to-allow-mappings-up-to-the-end.patch