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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 EDA3AC3A5A3 for ; Thu, 22 Aug 2019 17:36:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C7527233FC for ; Thu, 22 Aug 2019 17:36:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566495361; bh=tCn+yBMdeNEJkOqrVkSmW+4rs9IZI/a8BsEGVLrqZac=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=Onrf6cQ9deG31nTpLUpgXvyXG0CddjZqqnJiVXPbi1YSIXcI2jpWMv9Kk7ifcdjs7 zc+zloJaYGrj/X8wVScyUNF7fqs3iOAB8Xm7bBYBPAv8Cf/cIOeEbOlGj3Z3vfhPde so2uzmGpFX7D+wDDSqmD82cxaC5QHnMQyDJRNU4M= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392473AbfHVRgA (ORCPT ); Thu, 22 Aug 2019 13:36:00 -0400 Received: from mail.kernel.org ([198.145.29.99]:47072 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391783AbfHVRY5 (ORCPT ); Thu, 22 Aug 2019 13:24:57 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 9BDAC2341C; Thu, 22 Aug 2019 17:24:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494696; bh=tCn+yBMdeNEJkOqrVkSmW+4rs9IZI/a8BsEGVLrqZac=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VReyHMTQnV1oDAApR8YYXJHuZtCtePCQbCQz7ujVKkEfGEPrR9V1jgWKuZCJFzAuz dBXNs9ZvqE8QTbuw/XDmyzEiXS6oNGfbkcwZQ0BRSYOJ8lt/DzaRVcb16pgHiHWdCO qqNR4GBNysMXvoW/1z96Ny8lvLo/oVT4whwpbIoA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Prasad Sodagudi , "Isaac J. Manjarres" , William Kucharski , Kees Cook , Trilok Soni , Andrew Morton , Linus Torvalds Subject: [PATCH 4.14 03/71] mm/usercopy: use memory range to be accessed for wraparound check Date: Thu, 22 Aug 2019 10:18:38 -0700 Message-Id: <20190822171726.369782143@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171726.131957995@linuxfoundation.org> References: <20190822171726.131957995@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Isaac J. Manjarres commit 951531691c4bcaa59f56a316e018bc2ff1ddf855 upstream. Currently, when checking to see if accessing n bytes starting at address "ptr" will cause a wraparound in the memory addresses, the check in check_bogus_address() adds an extra byte, which is incorrect, as the range of addresses that will be accessed is [ptr, ptr + (n - 1)]. This can lead to incorrectly detecting a wraparound in the memory address, when trying to read 4 KB from memory that is mapped to the the last possible page in the virtual address space, when in fact, accessing that range of memory would not cause a wraparound to occur. Use the memory range that will actually be accessed when considering if accessing a certain amount of bytes will cause the memory address to wrap around. Link: http://lkml.kernel.org/r/1564509253-23287-1-git-send-email-isaacm@codeaurora.org Fixes: f5509cc18daa ("mm: Hardened usercopy") Signed-off-by: Prasad Sodagudi Signed-off-by: Isaac J. Manjarres Co-developed-by: Prasad Sodagudi Reviewed-by: William Kucharski Acked-by: Kees Cook Cc: Greg Kroah-Hartman Cc: Trilok Soni Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds [kees: backport to v4.14] Signed-off-by: Kees Cook Signed-off-by: Greg Kroah-Hartman --- mm/usercopy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/usercopy.c +++ b/mm/usercopy.c @@ -121,7 +121,7 @@ static inline const char *check_kernel_t static inline const char *check_bogus_address(const void *ptr, unsigned long n) { /* Reject if object wraps past end of memory. */ - if ((unsigned long)ptr + n < (unsigned long)ptr) + if ((unsigned long)ptr + (n - 1) < (unsigned long)ptr) return ""; /* Reject if NULL or ZERO-allocation. */