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=-17.4 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT, USER_IN_DEF_DKIM_WL 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 EFA65C433E2 for ; Wed, 17 Jun 2020 22:32:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CA12520CC7 for ; Wed, 17 Jun 2020 22:32:43 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="vKdUwab7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727813AbgFQWcm (ORCPT ); Wed, 17 Jun 2020 18:32:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49412 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727788AbgFQWci (ORCPT ); Wed, 17 Jun 2020 18:32:38 -0400 Received: from mail-yb1-xb4a.google.com (mail-yb1-xb4a.google.com [IPv6:2607:f8b0:4864:20::b4a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6336CC06174E for ; Wed, 17 Jun 2020 15:32:38 -0700 (PDT) Received: by mail-yb1-xb4a.google.com with SMTP id f130so4269348yba.9 for ; Wed, 17 Jun 2020 15:32:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:message-id:mime-version:subject:from:to:cc; bh=dl8CpF2u3zjH2sdeNdfuapWfq9PffavQBlO7OcAgrZI=; b=vKdUwab7uP+uz/ILCRIEQUWTw1y628cbUve5KPb0pU8jh01zB0o77mA5nagbMWOTSc 7OOwmSa0HgM1N5d2qYpqBxZ8X+9/CKPCT1I04mArfiOOHR/qZI6+6iy5xVqmsR9plMsS bE6eVXckKiCki3ClaPCxsyQPigQ/nWS/d2H9mRrqEH75uYmmxx3QCGYHAUx6HjqAZh8g Mhyw/prWu186TWslGG8SCdgJe47c5ED2M13op9MyZvNCrv0OcxuPMgclpMMPqO+tM475 iWVA8XbKP4MbrhyEkoFEU0GU8iqUk+TSFLAnT97+NN9kfOzfMEDqPh6wTipvvHQQ+2e5 O1Hw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:message-id:mime-version:subject:from:to:cc; bh=dl8CpF2u3zjH2sdeNdfuapWfq9PffavQBlO7OcAgrZI=; b=G74OwxMvx1OmEqm3xXm+a0ZbiPk82q+/OV4CftgYbxWxghIN2uGZmtWvNrdY7H17J7 4hcVELhCi51WRnJGm1XrIINby1AnlD09+mS2if2i4KEivGjI9ym+5OjDwPNx4dXh4dyI f+yrVKkJ9PteQszt0wnSmfweuRLww7+JaDqmcgaB/5gWYIw7HjTvtELjucEGJODpHAAR PSC/8smr0AffcqrSWLs2q4n5/jjSBYzlahBgfK02/Ygzc40vugsGfE5CXpn/vZjjvMaH X0indRK6winmIjh3OT1nVXDvSt5hrwxn1erBfEcW6gpCovPL6LHGr5eD89TNK2Pq/vML uiNg== X-Gm-Message-State: AOAM533B7QMrtSIQZlx+t1VxGjzlCCdYkx0VXkTKpxRUCt4UN6V2jwoT rceVxhD21J4FzhIn1ZVINOqx5wfS4hAkrH4= X-Google-Smtp-Source: ABdhPJyeR4h0Me2Jqjjk5lMCpwfmgkUJ7m4BZVHZC7e5A3/e2NJJt9P6ANUw0qyp4w9dB87DwkgcWPw7kiZQu0o= X-Received: by 2002:a25:73c3:: with SMTP id o186mr1779854ybc.230.1592433157594; Wed, 17 Jun 2020 15:32:37 -0700 (PDT) Date: Wed, 17 Jun 2020 15:32:29 -0700 Message-Id: <20200617223229.165040-1-zhangalex@google.com> Mime-Version: 1.0 X-Mailer: git-send-email 2.27.0.111.gc72c7da667-goog Subject: [PATCH] mm/memory.c: make remap_pfn_range() reject unaligned addr From: Kaiyu Zhang To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Alex Zhang Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alex Zhang 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 adding a check for it. Signed-off-by: Alex Zhang --- mm/memory.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index dc7f3543b1fd..9cb0a75f1555 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -2081,7 +2081,7 @@ static inline int remap_p4d_range(struct mm_struct *mm, pgd_t *pgd, /** * 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 @@ -2100,6 +2100,9 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr, unsigned long remap_pfn = pfn; int err; + if (!PAGE_ALIGN(addr)) + return -EINVAL; + /* * Physically remapped pages are special. Tell the * rest of the world about it: -- 2.27.0.290.gba653c62da-goog