From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5F642C43603 for ; Tue, 17 Dec 2019 10:23:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 326E72067C for ; Tue, 17 Dec 2019 10:23:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727434AbfLQKXj (ORCPT ); Tue, 17 Dec 2019 05:23:39 -0500 Received: from smtp1.axis.com ([195.60.68.17]:4462 "EHLO smtp1.axis.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726411AbfLQKXj (ORCPT ); Tue, 17 Dec 2019 05:23:39 -0500 IronPort-SDR: olos7RgV0aFCzW+bUUn0tK2MWoDKJsoEdL/t1GiX/kM71PMjnlnsXWjAXZLSiau3qWEvI4Lj6R X2sjFQfSJfg8bkB/gNmbizfkYrWeHroDKeisiU+YEaMgQtBCGRIQYWUsiIC1vUQLY1UdEugjVq +j9l43yK0Mhl1nCj2FTAkMKmTusAvdn527/q7slSaR5Ni2ENYzBzwT5zI8RKHGXrO+f15WL2Zc Ur3GXjJcV/AQXpxozLus0K7XfQL9Mg6BRBoa5mtbBlMW+hBGI4RcGn6jl2nEDzrTmSQJgZChsM Q9E= X-IronPort-AV: E=Sophos;i="5.69,325,1571695200"; d="scan'208";a="3670839" X-Axis-User: NO X-Axis-NonUser: YES X-Virus-Scanned: Debian amavisd-new at bastet.se.axis.com From: Vincent Whitchurch To: akpm@linux-foundation.org Cc: arnd@arndb.de, treding@nvidia.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Vincent Whitchurch Subject: [PATCH] asm/sections: Check for overflow in memory_contains() Date: Tue, 17 Dec 2019 11:22:38 +0100 Message-Id: <20191217102238.14792-1-vincent.whitchurch@axis.com> X-Mailer: git-send-email 2.20.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org ARM uses memory_contains() from its stacktrace code via this function: static inline bool in_entry_text(unsigned long addr) { return memory_contains(__entry_text_start, __entry_text_end, (void *)addr, 1); } addr is taken from the stack and can be a completely invalid. If addr is 0xffffffff, there is an overflow in the pointer arithmetic in memory_contains() and in_entry_text() incorrectly returns true. Fix this by adding an overflow check. The check is done on unsigned longs to avoid undefined behaviour. Signed-off-by: Vincent Whitchurch --- include/asm-generic/sections.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/include/asm-generic/sections.h b/include/asm-generic/sections.h index d1779d442aa5..e6e1b381c5df 100644 --- a/include/asm-generic/sections.h +++ b/include/asm-generic/sections.h @@ -105,7 +105,15 @@ static inline int arch_is_kernel_initmem_freed(unsigned long addr) static inline bool memory_contains(void *begin, void *end, void *virt, size_t size) { - return virt >= begin && virt + size <= end; + unsigned long membegin = (unsigned long)begin; + unsigned long memend = (unsigned long)end; + unsigned long objbegin = (unsigned long)virt; + unsigned long objend = objbegin + size; + + if (objend < objbegin) + return false; + + return objbegin >= membegin && objend <= memend; } /** -- 2.20.0