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 DE378C433E1 for ; Wed, 17 Jun 2020 22:34:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B98F22098B for ; Wed, 17 Jun 2020 22:34:20 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="XZbDoRPx" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727029AbgFQWeT (ORCPT ); Wed, 17 Jun 2020 18:34:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49676 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726840AbgFQWeT (ORCPT ); Wed, 17 Jun 2020 18:34:19 -0400 Received: from mail-yb1-xb49.google.com (mail-yb1-xb49.google.com [IPv6:2607:f8b0:4864:20::b49]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B1356C06174E for ; Wed, 17 Jun 2020 15:34:17 -0700 (PDT) Received: by mail-yb1-xb49.google.com with SMTP id f130so4273642yba.9 for ; Wed, 17 Jun 2020 15:34:17 -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=XZbDoRPx9MaqRuyRsuE/Zz84rdx1Xg4cSOXtmTvC/TW75TfM/II++KXvkmOZ41Yqf6 k0aimUW4ZwWVH3K11wIO5XxCn5FW6ghYzMqX6KekiZf7JAT+9xphRLQFmGCeSf2oWv2B joYHJsCZPN4lBHirZGH3DZRwU5eUSMEaMqB7Kf68HK4NaGlSZXTbS0af4dhERrXKNZ0O C6ROehJ0qKo+jcU7S0430TM9qa1DqWbamBFaRIdN1LWNkSr55f52P4EJEO6/tu4jdhdh sY4C0ESIhkZi3FAp6qi/HhG/QDIzDfFSu+UyLm7nC8Yv/FRs/bez0w6Kd2cDoHu7F+zT 21zw== 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=uBIl7MSrxIbn4JubjZZIb9BfrF4d4zeLNVpDdrkAq/C43aNJFyHXijMhvpPE1VuhwR ZEWhVafSLSxE/6dvsJl7iRzFlgU+gMGewLa3TSGejxtU273eaNZT4TgVSTWV45XILnCE ++exCZ7Z4etxXjtSVFjcIS0C1kNqeC8gpsOnpKfOjhAPdWWXfSzDRPd08CDTs66/EKe4 B5bN0m/5YRf2Gh2LeB12eJNnn0xb0Cki9T65AVNXyXwtZ0tzwNbZv1OjsBda4GVWbnWy +limHAOlSDt7/dwlhwkV2x/Kx+G53niHo3/IIjjJpKbwXwTFzoGrP/7222xkjMJ/fclX z9xw== X-Gm-Message-State: AOAM531XO2IxwyEVonGy8vGsz8vPb6vBA3cp7zlu6oakcmfBE/f0znCW kPqnDNW4gazYUdV3j+pXxJdq4ZOYwBuspxo= X-Google-Smtp-Source: ABdhPJwSX0MoqylBaNHo5+aHvkEKKYVU9E5bWuZtt82sujJuI/YxK/IxNKn5uJvJu1RQHd461b7kt2QU2QPNQUY= X-Received: by 2002:a25:3784:: with SMTP id e126mr2000871yba.267.1592433256945; Wed, 17 Jun 2020 15:34:16 -0700 (PDT) Date: Wed, 17 Jun 2020 15:34:14 -0700 Message-Id: <20200617223414.165923-1-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