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=-8.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 43BDBC282C0 for ; Fri, 25 Jan 2019 17:38:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0D318218A6 for ; Fri, 25 Jan 2019 17:38:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="nf8Bb+7W" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729161AbfAYRiq (ORCPT ); Fri, 25 Jan 2019 12:38:46 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:52506 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbfAYRiq (ORCPT ); Fri, 25 Jan 2019 12:38:46 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Message-Id:Date:Subject:Cc:To:From: Sender:Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=5fm7+VQclmc9hs1XdDfzoo0+kGTLRUZeg8UOcg8q+Z4=; b=nf8Bb+7W8x8wxgblLvy6oWMic d652mU0FzZk0JJee7uTAu8bH38PuCNnOgXPoWfLnj6NvmVvMVGjnWFKC+RDBigMq35LO4lvc7D7dn rkSem+D3vPoXfBabKSOPe+i9kSlzYTl2Lay6bBxCfYHkojLqgj3vawCoDKa9BbKQ4kYWJdGX0iNUC HdjdIt518XQF7vHcGAI2CShiycADvgCzYmkWMrvXwq4giB+5GXJPlzdqeL4br4whw8XZp0nVtlG62 cCL2HclCSzKdzKjbuibSwZTUrnauEnJ7RfLH3cMctor6SHckglSa9UgEI145lPqlCPIHzgqNhDHcz EJkl3+VbQ==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1gn5R9-0000hr-Ei; Fri, 25 Jan 2019 17:38:39 +0000 From: Matthew Wilcox To: Andrew Morton Cc: Matthew Wilcox , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Rik van Riel , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , kernel-hardening@lists.openwall.com, Kees Cook , Michael Ellerman Subject: [PATCH] mm: Prevent mapping slab pages to userspace Date: Fri, 25 Jan 2019 09:38:27 -0800 Message-Id: <20190125173827.2658-1-willy@infradead.org> X-Mailer: git-send-email 2.14.5 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It's never appropriate to map a page allocated by SLAB into userspace. A buggy device driver might try this, or an attacker might be able to find a way to make it happen. Signed-off-by: Matthew Wilcox --- mm/memory.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memory.c b/mm/memory.c index e11ca9dd823f..ce8c90b752be 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1451,7 +1451,7 @@ static int insert_page(struct vm_area_struct *vma, unsigned long addr, spinlock_t *ptl; retval = -EINVAL; - if (PageAnon(page)) + if (PageAnon(page) || PageSlab(page)) goto out; retval = -ENOMEM; flush_dcache_page(page); -- 2.20.1