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=-7.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 E426BC433DF for ; Fri, 7 Aug 2020 06:22:27 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A157F22C9F for ; Fri, 7 Aug 2020 06:22:27 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="2euGcCb0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A157F22C9F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3D0798D0068; Fri, 7 Aug 2020 02:22:27 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 3816F8D0026; Fri, 7 Aug 2020 02:22:27 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 271C18D0068; Fri, 7 Aug 2020 02:22:27 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0197.hostedemail.com [216.40.44.197]) by kanga.kvack.org (Postfix) with ESMTP id 101858D0026 for ; Fri, 7 Aug 2020 02:22:27 -0400 (EDT) Received: from smtpin28.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with ESMTP id C916382499A8 for ; Fri, 7 Aug 2020 06:22:26 +0000 (UTC) X-FDA: 77122778292.28.hall09_1a0c76826fbe Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin28.hostedemail.com (Postfix) with ESMTP id AFD7E6D74 for ; Fri, 7 Aug 2020 06:22:26 +0000 (UTC) X-HE-Tag: hall09_1a0c76826fbe X-Filterd-Recvd-Size: 2867 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf20.hostedemail.com (Postfix) with ESMTP for ; Fri, 7 Aug 2020 06:22:26 +0000 (UTC) Received: from localhost.localdomain (c-73-231-172-41.hsd1.ca.comcast.net [73.231.172.41]) (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 6495F2177B; Fri, 7 Aug 2020 06:22:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1596781345; bh=ZKPDNveFMOs5PNNaKoZIbOLuceh7796kjd4EhLCYqY4=; h=Date:From:To:Subject:In-Reply-To:From; b=2euGcCb0N92qpHG0GSBFy6FzLbMUkXKI9sWd+nA/c4FF1nTOJsZ2aNyTrPbuLw/Qn GbxF7j0b03v8NlrJUbOhxtyyvWx4DiEGTUMxvbD2m3rgAVL5LHe6uEFaFRGwCTpRSt xFHkOk0MopAxtJTOEdw8vsSMKhlHYDs1yR4SGlxA= Date: Thu, 06 Aug 2020 23:22:24 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, zhangalex@google.com Subject: [patch 095/163] mm/memory.c: make remap_pfn_range() reject unaligned addr Message-ID: <20200807062224.b7xjNHWMw%akpm@linux-foundation.org> In-Reply-To: <20200806231643.a2711a608dd0f18bff2caf2b@linux-foundation.org> User-Agent: s-nail v14.8.16 X-Rspamd-Queue-Id: AFD7E6D74 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam03 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Alex Zhang Subject: mm/memory.c: make remap_pfn_range() reject unaligned addr This function implicitly assumes that the addr passed in is page aligned. A non page aligned addr could ultimately cause a kernel bug in remap_pte_range as the exit condition in the logic loop may never be satisfied. This patch documents the need for the requirement, as well as explicitly adds a check for it. Link: http://lkml.kernel.org/r/20200617233512.177519-1-zhangalex@google.com Signed-off-by: Alex Zhang Reviewed-by: Andrew Morton Signed-off-by: Andrew Morton --- mm/memory.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/mm/memory.c~mm-memoryc-make-remap_pfn_range-reject-unaligned-addr +++ a/mm/memory.c @@ -2082,7 +2082,7 @@ static inline int remap_p4d_range(struct /** * remap_pfn_range - remap kernel memory to userspace * @vma: user vma to map to - * @addr: target user address to start at + * @addr: target page aligned user address to start at * @pfn: page frame number of kernel physical memory address * @size: size of mapping area * @prot: page protection flags for this mapping @@ -2101,6 +2101,9 @@ int remap_pfn_range(struct vm_area_struc unsigned long remap_pfn = pfn; int err; + if (WARN_ON_ONCE(!PAGE_ALIGNED(addr))) + return -EINVAL; + /* * Physically remapped pages are special. Tell the * rest of the world about it: _