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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1D553CA0EC3 for ; Tue, 12 Sep 2023 05:30:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231191AbjILFay (ORCPT ); Tue, 12 Sep 2023 01:30:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50462 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230391AbjILFax (ORCPT ); Tue, 12 Sep 2023 01:30:53 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9831FAA for ; Mon, 11 Sep 2023 22:30:49 -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=pOmLWIw3f42oY6r0FprJ4GU/jYGQV5Prcd0Ezz08Nb0=; b=Q1B1uniPeTbt8adeldz9ohu+yl mOGkYN1Ejb5yo5sHQ6iMK/1s125VV0/wEVg7mQi7tqTnpD7/b6Wf6PRq3dgiNFsMoIxXnFJj64MZy 3moAPD7FMFkwPifHxQ4pB7/75bmCMN5IQvSn7TnnooB5gSWoyCSB5NSHdWTF+e4gccHzNa+rOdvIa zaErjtI34SPDvQCoI36JUmN7kxmsqDbDzTPm2BNo5rXIHkzkH1caqi6Ug2HHtq4PMGBlUAhIlUEO4 p46CYTu5RUOzWF4ZYqSOawy/0czw4tq8QLzxSMrtwJUhe20RRKa+Uevvs2qmsIS5SQKPkQn1YN7Ex ibzberPA==; Received: from willy by casper.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1qfvz4-005khz-7L; Tue, 12 Sep 2023 05:30:46 +0000 Date: Tue, 12 Sep 2023 06:30:46 +0100 From: Matthew Wilcox To: syzbot Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [mm?] kernel BUG in vma_replace_policy Message-ID: References: <000000000000f392a60604a65085@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <000000000000f392a60604a65085@google.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 05, 2023 at 06:03:49PM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: a47fc304d2b6 Add linux-next specific files for 20230831 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=16502ddba80000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6ecd2a74f20953b9 > dashboard link: https://syzkaller.appspot.com/bug?extid=b591856e0f0139f83023 > compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=120e7d70680000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1523f9c0680000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/b2e8f4217527/disk-a47fc304.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/ed6cdcc09339/vmlinux-a47fc304.xz > kernel image: https://storage.googleapis.com/syzbot-assets/bd9b2475bf5a/bzImage-a47fc304.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+b591856e0f0139f83023@syzkaller.appspotmail.com #syz test diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 42b5567e3773..90ad5fe60824 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1342,6 +1342,7 @@ static long do_mbind(unsigned long start, unsigned long len, vma_iter_init(&vmi, mm, start); prev = vma_prev(&vmi); for_each_vma_range(vmi, vma, end) { + vma_start_write(vma); err = mbind_range(&vmi, vma, &prev, start, end, new); if (err) break;