Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966546AbcDLUyD (ORCPT ); Tue, 12 Apr 2016 16:54:03 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:50865 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966526AbcDLUx7 (ORCPT ); Tue, 12 Apr 2016 16:53:59 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Helge Deller , Kees Cook , Kamal Mostafa Subject: [PATCH 4.2.y-ckt 49/70] parisc: Fix kernel crash with reversed copy_from_user() Date: Tue, 12 Apr 2016 13:52:34 -0700 Message-Id: <1460494375-30070-50-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1460494375-30070-1-git-send-email-kamal@canonical.com> References: <1460494375-30070-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 4.2 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1288 Lines: 38 4.2.8-ckt8 -stable review patch. If anyone has any objections, please let me know. ---8<------------------------------------------------------------ From: Helge Deller commit ef72f3110d8b19f4c098a0bff7ed7d11945e70c6 upstream. The kernel module testcase (lib/test_user_copy.c) exhibited a kernel crash on parisc if the parameters for copy_from_user were reversed ("illegal reversed copy_to_user" testcase). Fix this potential crash by checking the fault handler if the faulting address is in the exception table. Signed-off-by: Helge Deller Cc: Kees Cook Signed-off-by: Kamal Mostafa --- arch/parisc/kernel/traps.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/parisc/kernel/traps.c b/arch/parisc/kernel/traps.c index b99b39f..3419668 100644 --- a/arch/parisc/kernel/traps.c +++ b/arch/parisc/kernel/traps.c @@ -798,6 +798,9 @@ void notrace handle_interruption(int code, struct pt_regs *regs) if (fault_space == 0 && !faulthandler_disabled()) { + /* Clean up and return if in exception table. */ + if (fixup_exception(regs)) + return; pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC); parisc_terminate("Kernel Fault", regs, code, fault_address); } -- 2.7.4