From patchwork Thu Sep 2 21:56:46 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Andrew Morton X-Patchwork-Id: 12473081 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=-15.8 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 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 B9A41C433EF for ; Thu, 2 Sep 2021 21:56:49 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 62F496056B for ; Thu, 2 Sep 2021 21:56:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 62F496056B 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=kvack.org Received: by kanga.kvack.org (Postfix) id EDF2A6B0123; Thu, 2 Sep 2021 17:56:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id E8F626B0124; Thu, 2 Sep 2021 17:56:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D7EAF6B0125; Thu, 2 Sep 2021 17:56:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0062.hostedemail.com [216.40.44.62]) by kanga.kvack.org (Postfix) with ESMTP id C9DD86B0123 for ; Thu, 2 Sep 2021 17:56:48 -0400 (EDT) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id 976AB284BD for ; Thu, 2 Sep 2021 21:56:48 +0000 (UTC) X-FDA: 78543993696.09.6C76131 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by imf27.hostedemail.com (Postfix) with ESMTP id 3DAFB700009D for ; Thu, 2 Sep 2021 21:56:48 +0000 (UTC) Received: by mail.kernel.org (Postfix) with ESMTPSA id 41371603E9; Thu, 2 Sep 2021 21:56:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1630619807; bh=2193Zu4lnKPlUV1Oy4tikW1izveRDzhhsPeeRlBmfLk=; h=Date:From:To:Subject:In-Reply-To:From; b=ez12LioqIZXuM09mLr7zsp7Da9fmaSEfO/CjhzRnTtcPt6INPfWA5qrWNdJ7XqhO+ NqO88rq0Ayto30nSLih/O6kmlTU0JqivMtwyJMMWIvIng20OIB9CJEuf7J+00qRVfN 35eZKlO5bSIWaolx4n6KasJ3QR7RGbLzJaMiQd4g= Date: Thu, 02 Sep 2021 14:56:46 -0700 From: Andrew Morton To: akpm@linux-foundation.org, linux-mm@kvack.org, lrizzo@google.com, mm-commits@vger.kernel.org, rientjes@google.com, torvalds@linux-foundation.org Subject: [patch 127/212] mm/pagemap: add mmap_assert_locked() annotations to find_vma*() Message-ID: <20210902215646.xFeHkxgj1%akpm@linux-foundation.org> In-Reply-To: <20210902144820.78957dff93d7bea620d55a89@linux-foundation.org> User-Agent: s-nail v14.8.16 Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=ez12Lioq; spf=pass (imf27.hostedemail.com: domain of akpm@linux-foundation.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none X-Stat-Signature: yguimzemet33uq7w1a3d4zm9a6d9wbab X-Rspamd-Queue-Id: 3DAFB700009D X-Rspamd-Server: rspam04 X-HE-Tag: 1630619808-778046 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: Luigi Rizzo Subject: mm/pagemap: add mmap_assert_locked() annotations to find_vma*() find_vma() and variants need protection when used. This patch adds mmap_assert_lock() calls in the functions. To make sure the invariant is satisfied, we also need to add a mmap_read_loc() around the get_user_pages_remote() call in get_arg_page(). The lock is not strictly necessary because the mm has been newly created, but the extra cost is limited because the same mutex was also acquired shortly before in __bprm_mm_init(), so it is hot and uncontended. [penguin-kernel@i-love.sakura.ne.jp: TOMOYO needs the same protection which get_arg_page() needs] Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp Link: https://lkml.kernel.org/r/20210731175341.3458608-1-lrizzo@google.com Signed-off-by: Luigi Rizzo Cc: David Rientjes Signed-off-by: Andrew Morton --- fs/exec.c | 2 ++ mm/mmap.c | 2 ++ security/tomoyo/domain.c | 13 +++++++++---- 3 files changed, 13 insertions(+), 4 deletions(-) --- a/fs/exec.c~add-mmap_assert_locked-annotations-to-find_vma +++ a/fs/exec.c @@ -217,8 +217,10 @@ static struct page *get_arg_page(struct * We are doing an exec(). 'current' is the process * doing the exec and bprm->mm is the new process's mm. */ + mmap_read_lock(bprm->mm); ret = get_user_pages_remote(bprm->mm, pos, 1, gup_flags, &page, NULL, NULL); + mmap_read_unlock(bprm->mm); if (ret <= 0) return NULL; --- a/mm/mmap.c~add-mmap_assert_locked-annotations-to-find_vma +++ a/mm/mmap.c @@ -534,6 +534,7 @@ static int find_vma_links(struct mm_stru { struct rb_node **__rb_link, *__rb_parent, *rb_prev; + mmap_assert_locked(mm); __rb_link = &mm->mm_rb.rb_node; rb_prev = __rb_parent = NULL; @@ -2303,6 +2304,7 @@ struct vm_area_struct *find_vma(struct m struct rb_node *rb_node; struct vm_area_struct *vma; + mmap_assert_locked(mm); /* Check the cache first. */ vma = vmacache_find(mm, addr); if (likely(vma)) --- a/security/tomoyo/domain.c~add-mmap_assert_locked-annotations-to-find_vma +++ a/security/tomoyo/domain.c @@ -897,6 +897,9 @@ bool tomoyo_dump_page(struct linux_binpr struct tomoyo_page_dump *dump) { struct page *page; +#ifdef CONFIG_MMU + int ret; +#endif /* dump->data is released by tomoyo_find_next_domain(). */ if (!dump->data) { @@ -909,11 +912,13 @@ bool tomoyo_dump_page(struct linux_binpr /* * This is called at execve() time in order to dig around * in the argv/environment of the new proceess - * (represented by bprm). 'current' is the process doing - * the execve(). + * (represented by bprm). */ - if (get_user_pages_remote(bprm->mm, pos, 1, - FOLL_FORCE, &page, NULL, NULL) <= 0) + mmap_read_lock(bprm->mm); + ret = get_user_pages_remote(bprm->mm, pos, 1, + FOLL_FORCE, &page, NULL, NULL); + mmap_read_unlock(bprm->mm); + if (ret <= 0) return false; #else page = bprm->page[pos / PAGE_SIZE];