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=-3.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 69F74C43463 for ; Fri, 18 Sep 2020 20:04:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1428422208 for ; Fri, 18 Sep 2020 20:04:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="PMG5G25s" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726335AbgIRUEP (ORCPT ); Fri, 18 Sep 2020 16:04:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51080 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726252AbgIRUEO (ORCPT ); Fri, 18 Sep 2020 16:04:14 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0CDFBC0613CE for ; Fri, 18 Sep 2020 13:04:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=qYaEAszQv6v4if8wYRImkPIKWHq2MR9K6P/7rHDEe6w=; b=PMG5G25stfvlOdt8U6PcP8yPtt WczUHLk3P6quZDIv6WHLI3s9rizVmKdxM9o/p6dd8YL5BlcdCM8B+aK7hK7cmO7gWjmuAU2pBGOir 0Q5jvukBXbLbmB1Tv3KaaynOj3Wrj7vj4oc/e1jiMq9vpA1w7NjkUmZFF1YRToPIu7JhZNJK/lMxj gMNnwP44jtSN3QG/PkgO54VRDgMomtZroefFIfOoCzHEJ6dv4GeGdGtq5Xzs4/uFf1fakhQ4T4joi 0XGbaidN1k127sdVT3xnIGyTAvoA3vfCypu7K2sT3Kn04JrROKYUmbGhMdKNbjSZ5DyDt2vNbgFgz ilk+WQ4g==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1kJMc6-0003o1-Ol; Fri, 18 Sep 2020 20:04:10 +0000 Date: Fri, 18 Sep 2020 21:04:10 +0100 From: Matthew Wilcox To: Mike Kravetz Cc: syzbot , akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com Subject: Re: KASAN: null-ptr-deref Read in PageHuge Message-ID: <20200918200410.GI32101@casper.infradead.org> References: <0000000000000cea4605af946f8c@google.com> <3747b978-77d7-93b3-eca4-28010fab5d01@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3747b978-77d7-93b3-eca4-28010fab5d01@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Sep 18, 2020 at 12:42:24PM -0700, Mike Kravetz wrote: > On 9/18/20 4:02 AM, syzbot wrote: > > ================================================================== > > BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline] > > BUG: KASAN: null-ptr-deref in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] > > BUG: KASAN: null-ptr-deref in PageCompound include/linux/page-flags.h:196 [inline] > > BUG: KASAN: null-ptr-deref in PageHuge+0x19/0x170 mm/hugetlb.c:1551 > > Read of size 8 at addr 0000000000000000 by task syz-executor410/6864 > > > > I assume this would also be fixed by 5d1903f712ac > ("mm-convert-find_get_entry-to-return-the-head-page-fix") That's a good bet.