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 DDC53C2BD09 for ; Fri, 6 Dec 2019 13:54:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BEFE420706 for ; Fri, 6 Dec 2019 13:54:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726823AbfLFNy2 (ORCPT ); Fri, 6 Dec 2019 08:54:28 -0500 Received: from foss.arm.com ([217.140.110.172]:44816 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726809AbfLFNyZ (ORCPT ); Fri, 6 Dec 2019 08:54:25 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 951F3113E; Fri, 6 Dec 2019 05:54:24 -0800 (PST) Received: from e112269-lin.cambridge.arm.com (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 157723F718; Fri, 6 Dec 2019 05:54:21 -0800 (PST) From: Steven Price To: Andrew Morton , linux-mm@kvack.org Cc: Steven Price , Andy Lutomirski , Ard Biesheuvel , Arnd Bergmann , Borislav Petkov , Catalin Marinas , Dave Hansen , Ingo Molnar , James Morse , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Peter Zijlstra , Thomas Gleixner , Will Deacon , x86@kernel.org, "H. Peter Anvin" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Rutland , "Liang, Kan" Subject: [PATCH v16 14/25] mm: pagewalk: fix termination condition in walk_pte_range() Date: Fri, 6 Dec 2019 13:53:05 +0000 Message-Id: <20191206135316.47703-15-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191206135316.47703-1-steven.price@arm.com> References: <20191206135316.47703-1-steven.price@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If walk_pte_range() is called with a 'end' argument that is beyond the last page of memory (e.g. ~0UL) then the comparison between 'addr' and 'end' will always fail and the loop will be infinite. Instead change the comparison to >= while accounting for overflow. Signed-off-by: Steven Price --- mm/pagewalk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 1b9a3ba24c51..88104ab00a97 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -18,9 +18,9 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, err = ops->pte_entry(pte, addr, addr + PAGE_SIZE, walk); if (err) break; - addr += PAGE_SIZE; - if (addr == end) + if (addr >= end - PAGE_SIZE) break; + addr += PAGE_SIZE; pte++; } -- 2.20.1 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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,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 790AFC43603 for ; Fri, 6 Dec 2019 13:58:00 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2995020706 for ; Fri, 6 Dec 2019 13:58:00 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="h3STTnUC" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2995020706 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=8uhGn2gQ9q9r8T4m5MBpmoRtoRtB3VHZwrkPvos4ipw=; b=h3STTnUC6g3xJu kMCj82wsaHaQZe4e2Yup67XdcVUmkL5NZSXGkjOr45Q4TLtJzKniNo591kMqCnfUjGsj+izS6mhap m91rYwiUH6Tkd19E8mIIyVVRuEs3ZIvWO1SDagDh3ZQOXHjxf7UYg+uTFtMoiakYXbAQTkeEJcxbC 1EOywxBZvtstW/cQFTS4VIg27mintLV7K1ojSwPBwjrtSGc2C6kno4dT/G1djcb++GVGc28gozpYu XsDNMrTBSAYYvMG8dMYhPalrRLAE2mCFDnnBgT4l4IWzvw8HQg3lHjziAc+3fkZs7IlDhuNoVcj+E GB30k49vyVySCRAgfu/A==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1idE7K-0007RV-3W; Fri, 06 Dec 2019 13:57:58 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1idE3t-000365-55 for linux-arm-kernel@lists.infradead.org; Fri, 06 Dec 2019 13:54:26 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 951F3113E; Fri, 6 Dec 2019 05:54:24 -0800 (PST) Received: from e112269-lin.cambridge.arm.com (e112269-lin.cambridge.arm.com [10.1.194.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 157723F718; Fri, 6 Dec 2019 05:54:21 -0800 (PST) From: Steven Price To: Andrew Morton , linux-mm@kvack.org Subject: [PATCH v16 14/25] mm: pagewalk: fix termination condition in walk_pte_range() Date: Fri, 6 Dec 2019 13:53:05 +0000 Message-Id: <20191206135316.47703-15-steven.price@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191206135316.47703-1-steven.price@arm.com> References: <20191206135316.47703-1-steven.price@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191206_055425_301547_D06400CD X-CRM114-Status: GOOD ( 12.27 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Mark Rutland , x86@kernel.org, Arnd Bergmann , Ard Biesheuvel , Peter Zijlstra , Catalin Marinas , Dave Hansen , linux-kernel@vger.kernel.org, Steven Price , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Ingo Molnar , Borislav Petkov , Andy Lutomirski , "H. Peter Anvin" , James Morse , Thomas Gleixner , Will Deacon , linux-arm-kernel@lists.infradead.org, "Liang, Kan" Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org If walk_pte_range() is called with a 'end' argument that is beyond the last page of memory (e.g. ~0UL) then the comparison between 'addr' and 'end' will always fail and the loop will be infinite. Instead change the comparison to >= while accounting for overflow. Signed-off-by: Steven Price --- mm/pagewalk.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 1b9a3ba24c51..88104ab00a97 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -18,9 +18,9 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, err = ops->pte_entry(pte, addr, addr + PAGE_SIZE, walk); if (err) break; - addr += PAGE_SIZE; - if (addr == end) + if (addr >= end - PAGE_SIZE) break; + addr += PAGE_SIZE; pte++; } -- 2.20.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel