From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:57359 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1032197AbbKFG65 (ORCPT ); Fri, 6 Nov 2015 01:58:57 -0500 Subject: Patch "um: Fix kernel mode fault condition" has been added to the 4.2-stable tree To: richard@nod.at, gregkh@linuxfoundation.org Cc: , From: Date: Thu, 05 Nov 2015 22:58:54 -0800 Message-ID: <144679313492185@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 um: Fix kernel mode fault condition to the 4.2-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: um-fix-kernel-mode-fault-condition.patch and it can be found in the queue-4.2 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 56b88a3bf97a39d3f4f010509917b76a865a6dc8 Mon Sep 17 00:00:00 2001 From: Richard Weinberger Date: Sun, 9 Aug 2015 22:26:33 +0200 Subject: um: Fix kernel mode fault condition From: Richard Weinberger commit 56b88a3bf97a39d3f4f010509917b76a865a6dc8 upstream. We have to exclude memory locations <= PAGE_SIZE from the condition and let the kernel mode fault path catch it. Otherwise a kernel NULL pointer exception will be reported as a kernel user space access. Fixes: d2313084e2c (um: Catch unprotected user memory access) Signed-off-by: Richard Weinberger Signed-off-by: Greg Kroah-Hartman --- arch/um/kernel/trap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/um/kernel/trap.c +++ b/arch/um/kernel/trap.c @@ -220,7 +220,7 @@ unsigned long segv(struct faultinfo fi, show_regs(container_of(regs, struct pt_regs, regs)); panic("Segfault with no mm"); } - else if (!is_user && address < TASK_SIZE) { + else if (!is_user && address > PAGE_SIZE && address < TASK_SIZE) { show_regs(container_of(regs, struct pt_regs, regs)); panic("Kernel tried to access user memory at addr 0x%lx, ip 0x%lx", address, ip); Patches currently in stable-queue which might be from richard@nod.at are queue-4.2/um-fix-kernel-mode-fault-condition.patch