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 5AE86C433E0 for ; Wed, 17 Jun 2020 23:35:19 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id E436121534 for ; Wed, 17 Jun 2020 23:35:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="j0e+CM9x" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E436121534 Authentication-Results: mail.kernel.org; dmarc=fail (p=reject dis=none) header.from=google.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 5338E6B000C; Wed, 17 Jun 2020 19:35:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4BD8D6B000D; Wed, 17 Jun 2020 19:35:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 35E5E6B000E; Wed, 17 Jun 2020 19:35:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0020.hostedemail.com [216.40.44.20]) by kanga.kvack.org (Postfix) with ESMTP id 1B8B86B000C for ; Wed, 17 Jun 2020 19:35:18 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C2910180AD81A for ; Wed, 17 Jun 2020 23:35:17 +0000 (UTC) X-FDA: 76940312274.17.field26_431041b26e0b Received: from filter.hostedemail.com (10.5.16.251.rfc1918.com [10.5.16.251]) by smtpin17.hostedemail.com (Postfix) with ESMTP id 9B740180D0180 for ; Wed, 17 Jun 2020 23:35:17 +0000 (UTC) X-HE-Tag: field26_431041b26e0b X-Filterd-Recvd-Size: 3809 Received: from mail-yb1-f201.google.com (mail-yb1-f201.google.com [209.85.219.201]) by imf15.hostedemail.com (Postfix) with ESMTP for ; Wed, 17 Jun 2020 23:35:17 +0000 (UTC) Received: by mail-yb1-f201.google.com with SMTP id w9so4547886ybt.2 for ; Wed, 17 Jun 2020 16:35:17 -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=JEk1DvV7StGc2B/4az6pcE4cQmGW6gMF8cmlGg/pUZM=; b=j0e+CM9xVYFln9suMskzdp0bkFPVo1HzPayGtWYP1pTrDO5Frq0ROsDIrVT6aDMb4J EN1HJSyyMuJRMtjXBoQfle9rmKXfLBGuoUDS7ycc2BNogqEEkxU4b/seLCRBpdbuCSal AEqBvOme/HaVNJ0dviRjXbh9T0upLKyfHMdAZbOXmtbWqPbylXISbdJDtSEZHPAfJ7YD g+Y6OAl/juHy0ZnfqFqZCcFLC5rTJRoPRHZGFNW9Gz1lktrK3m0MyKcvXTXRD34CNvF8 0UTee3wdgnDAcdjhreWcNcgNco2UZ+YFdaJW6oNI+91KbVkPH/IeSURv3/llA5+vvUGh uAqg== 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=JEk1DvV7StGc2B/4az6pcE4cQmGW6gMF8cmlGg/pUZM=; b=dpcnENXu6fKJygnNvQHquRJsd1EipFiSIiGl0JlsE6gNYPAqaYWXNoRKms2UN7rstl OnAkwW/+tjvAwghCq5dj9yTM3FlTl+khavo8aH/l+vjONh0js3EyQg7nrU9dX3/uf6BV x9bElwOGMj3DuLNkazaOp9F9wPVF+AIyPYJi8prVVri1E6Dg75rY61cfJHP1mTh4FUer Z5/2jizswA3x9e/avNZUCXHXZlNKeQv3UV20UYK2L3KSmZlQzfuIoWVzKKpoRbUNm+jJ 9cdT1TABEtmpJrQs5d7YVPTmfTMD0LJlNP+bhNuyNk4sXH1nCz3P6PvpX/Yon2RHaS/5 b4oQ== X-Gm-Message-State: AOAM530cFvCYpr2i0g5MrMCfB3b3i7ewe2TSZ7ddCXGrjTtiZNjfx5pj LkdHqekIhBantbET0EkKwJEOyq4r3TXeijA= X-Google-Smtp-Source: ABdhPJysIUfuTHo3ksbyMcJ6CJL1YB76sZVK1lq/+2uv1Jo29uya1Nyu+9Vkr14QoWK3Qd+ZH3K0ziSlqdlNLXw= X-Received: by 2002:a25:d68a:: with SMTP id n132mr2109309ybg.255.1592436916545; Wed, 17 Jun 2020 16:35:16 -0700 (PDT) Date: Wed, 17 Jun 2020 16:35:12 -0700 Message-Id: <20200617233512.177519-1-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" X-Rspamd-Queue-Id: 9B740180D0180 X-Spamd-Result: default: False [0.00 / 100.00] X-Rspamd-Server: rspam02 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 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. 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..16422acb6da8 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 (WARN_ON_ONCE(!PAGE_ALIGNED(addr))) + return -EINVAL; + /* * Physically remapped pages are special. Tell the * rest of the world about it: -- 2.27.0.111.gc72c7da667-goog