From patchwork Fri Aug 13 23:54:45 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 497002 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=-15.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED autolearn=unavailable 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 48DBCC4320A for ; Fri, 13 Aug 2021 23:54:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3278C61101 for ; Fri, 13 Aug 2021 23:54:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235805AbhHMXzN (ORCPT ); Fri, 13 Aug 2021 19:55:13 -0400 Received: from mail.kernel.org ([198.145.29.99]:39900 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235397AbhHMXzN (ORCPT ); Fri, 13 Aug 2021 19:55:13 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 99DDE610C8; Fri, 13 Aug 2021 23:54:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1628898886; bh=xN7uDkzQLv00XCsVvFZ+jfprpbgZTkT5VePR68D5fjg=; h=Date:From:To:Subject:In-Reply-To:From; b=0Me4an+Bt+HDevKlYVe1zaS8IgnSZQuWWxz1J/wF6o6xoSX7A2Iq1cg9u87u63rur OIXy7smYGKQ3t6Hc3vKoewJ/36jr/ITAYJZGzvHuWLB1F0WYmg3InFngSvcTW54iI1 UzHxRkT45WPXKHRsxAvJSUyF9vFe+l8LMNuW1tSE= Date: Fri, 13 Aug 2021 16:54:45 -0700 From: Andrew Morton To: akpm@linux-foundation.org, gregkh@linuxfoundation.org, linux-mm@kvack.org, linux@armlinux.org.uk, mcgrof@kernel.org, mm-commits@vger.kernel.org, nixiaoming@huawei.com, palmerdabbelt@google.com, stable@vger.kernel.org, torvalds@linux-foundation.org, wangkefeng.wang@huawei.com, wangliang101@huawei.com Subject: [patch 7/7] lib: use PFN_PHYS() in devmem_is_allowed() Message-ID: <20210813235445.iSOZmfuWE%akpm@linux-foundation.org> In-Reply-To: <20210813165350.dc9afa56d27eadbd8ce629c0@linux-foundation.org> User-Agent: s-nail v14.8.16 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Liang Wang Subject: lib: use PFN_PHYS() in devmem_is_allowed() The physical address may exceed 32 bits on 32-bit systems with more than 32 bits of physcial address. Use PFN_PHYS() in devmem_is_allowed(), or the physical address may overflow and be truncated. We found this bug when mapping a high addresses through devmem tool, when CONFIG_STRICT_DEVMEM is enabled on the ARM with ARM_LPAE and devmem is used to map a high address that is not in the iomem address range, an unexpected error indicating no permission is returned. This bug was initially introduced from v2.6.37, and the function was moved to lib when v5.11. Link: https://lkml.kernel.org/r/20210731025057.78825-1-wangliang101@huawei.com Fixes: 087aaffcdf9c ("ARM: implement CONFIG_STRICT_DEVMEM by disabling access to RAM via /dev/mem") Fixes: 527701eda5f1 ("lib: Add a generic version of devmem_is_allowed()") Signed-off-by: Liang Wang Reviewed-by: Luis Chamberlain Cc: Palmer Dabbelt Cc: Greg Kroah-Hartman Cc: Russell King Cc: Liang Wang Cc: Xiaoming Ni Cc: Kefeng Wang Cc: [2.6.37+] Signed-off-by: Andrew Morton --- lib/devmem_is_allowed.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/lib/devmem_is_allowed.c~lib-use-pfn_phys-in-devmem_is_allowed +++ a/lib/devmem_is_allowed.c @@ -19,7 +19,7 @@ */ int devmem_is_allowed(unsigned long pfn) { - if (iomem_is_exclusive(pfn << PAGE_SHIFT)) + if (iomem_is_exclusive(PFN_PHYS(pfn))) return 0; if (!page_is_ram(pfn)) return 1;