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 068E9C3A5A1 for ; Thu, 22 Aug 2019 17:31:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEE34233FD for ; Thu, 22 Aug 2019 17:31:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566495111; bh=1CYKAXKiR3PGLBCt5Dk6Fs+ZXrw2tCHPPNW8OOeyh4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=epgS2/4qyBtVVwmnrU17GVeyBPzxSBu7nsAY581nsUIQD0MpbI6h/utTzi6LaH671 hQdwVf1ahRQuo2wmBRNp1saF/elrBywfxyYVUo1ZhsztZ43YKG3KVL08g7aP/tJXME VElERrrzH/e7FxNewDBMTy1T2KuHhYhcLAjYN08A= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2392281AbfHVRbu (ORCPT ); Thu, 22 Aug 2019 13:31:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:49832 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404502AbfHVRZs (ORCPT ); Thu, 22 Aug 2019 13:25:48 -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 BC6FC23426; Thu, 22 Aug 2019 17:25:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494747; bh=1CYKAXKiR3PGLBCt5Dk6Fs+ZXrw2tCHPPNW8OOeyh4c=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=V4Z7JKX8rvKL9LDtkyOdxOiEvpJ85I1lBFy9eL92Mthfjo8GkKwRqrTWXH7gNzaP5 Q/dIevPTyQEYZmc+KooCzSJ9+nxvnAu5s8I/kBtOGZDX2VUsUXL8qsYZaRTxih/uez ueXKw72twzaVGDTIs6d0LTM7VivrhYoMr1+bUMn4= 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 4.19 07/85] mm/usercopy: use memory range to be accessed for wraparound check Date: Thu, 22 Aug 2019 10:18:40 -0700 Message-Id: <20190822171731.333203615@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171731.012687054@linuxfoundation.org> References: <20190822171731.012687054@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 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 @@ -151,7 +151,7 @@ static inline void check_bogus_address(c bool to_user) { /* Reject if object wraps past end of memory. */ - if (ptr + n < ptr) + if (ptr + (n - 1) < ptr) usercopy_abort("wrapped address", NULL, to_user, 0, ptr + n); /* Reject if NULL or ZERO-allocation. */