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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 36F63C31E40 for ; Tue, 6 Aug 2019 08:29:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0B6182075B for ; Tue, 6 Aug 2019 08:29:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565080158; bh=3edY4Y9PFCZ1ppIc6dRX/VFv9Pmaa5EO6FEFuE6ZR9w=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=ocN22QT41s8hQozUcLVrsUclRCJz4bu7BSQ565y0GnHrGIOtJgHrsMtEy3UgTTYbM 7yKuLxh20uW90GJnYrESyvMr3eXHv4SbtaG/NQOiX3AEZfVk0n/2Vwm24WBLHS8S/t FNLJ0FIFdVklJ7bzoKzMzFxRJ9EVrPzG+W8gap/s= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732295AbfHFI3R (ORCPT ); Tue, 6 Aug 2019 04:29:17 -0400 Received: from mx2.suse.de ([195.135.220.15]:55794 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728056AbfHFI3N (ORCPT ); Tue, 6 Aug 2019 04:29:13 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 9C99FAF1D; Tue, 6 Aug 2019 08:29:10 +0000 (UTC) Date: Tue, 6 Aug 2019 10:29:07 +0200 From: Michal Hocko To: Minchan Kim Cc: syzbot , akpm@linux-foundation.org, chris@chrisdown.name, chris@zankel.net, dancol@google.com, dave.hansen@intel.com, hannes@cmpxchg.org, hdanton@sina.com, james.bottomley@hansenpartnership.com, kirill.shutemov@linux.intel.com, ktkhai@virtuozzo.com, laoar.shao@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, mgorman@techsingularity.net, oleksandr@redhat.com, ralf@linux-mips.org, rth@twiddle.net, sfr@canb.auug.org.au, shakeelb@google.com, sonnyrao@google.com, surenb@google.com, syzkaller-bugs@googlegroups.com, timmurray@google.com, yang.shi@linux.alibaba.com Subject: Re: kernel BUG at mm/vmscan.c:LINE! (2) Message-ID: <20190806082907.GI11812@dhcp22.suse.cz> References: <000000000000a9694d058f261963@google.com> <20190802200643.GA181880@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190802200643.GA181880@google.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat 03-08-19 05:06:43, Minchan Kim wrote: > On Fri, Aug 02, 2019 at 10:58:05AM -0700, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: 0d8b3265 Add linux-next specific files for 20190729 > > git tree: linux-next > > console output: https://syzkaller.appspot.com/x/log.txt?x=1663c7d0600000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=ae96f3b8a7e885f7 > > dashboard link: https://syzkaller.appspot.com/bug?extid=8e6326965378936537c3 > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=133c437c600000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15645854600000 > > > > The bug was bisected to: > > > > commit 06a833a1167e9cbb43a9a4317ec24585c6ec85cb > > Author: Minchan Kim > > Date: Sat Jul 27 05:12:38 2019 +0000 > > > > mm: introduce MADV_PAGEOUT > > > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1545f764600000 > > final crash: https://syzkaller.appspot.com/x/report.txt?x=1745f764600000 > > console output: https://syzkaller.appspot.com/x/log.txt?x=1345f764600000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+8e6326965378936537c3@syzkaller.appspotmail.com > > Fixes: 06a833a1167e ("mm: introduce MADV_PAGEOUT") > > > > raw: 01fffc0000090025 dead000000000100 dead000000000122 ffff88809c49f741 > > raw: 0000000000020000 0000000000000000 00000002ffffffff ffff88821b6eaac0 > > page dumped because: VM_BUG_ON_PAGE(PageActive(page)) > > page->mem_cgroup:ffff88821b6eaac0 > > ------------[ cut here ]------------ > > kernel BUG at mm/vmscan.c:1156! > > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > > CPU: 1 PID: 9846 Comm: syz-executor110 Not tainted 5.3.0-rc2-next-20190729 > > #54 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > Google 01/01/2011 > > RIP: 0010:shrink_page_list+0x2872/0x5430 mm/vmscan.c:1156 > > My old version had PG_active flag clear but it seems to lose it with revising > patchsets. Thanks, Sizbot! > > >From 66d64988619ef7e86b0002b2fc20fdf5b84ad49c Mon Sep 17 00:00:00 2001 > From: Minchan Kim > Date: Sat, 3 Aug 2019 04:54:02 +0900 > Subject: [PATCH] mm: Clear PG_active on MADV_PAGEOUT > > shrink_page_list expects every pages as argument should be no active > LRU pages so we need to clear PG_active. Ups, missed that during review. > > Reported-by: syzbot+8e6326965378936537c3@syzkaller.appspotmail.com > Fixes: 06a833a1167e ("mm: introduce MADV_PAGEOUT") This is not a valid sha1 because it likely comes from linux-next. I guess Andrew will squash it into mm-introduce-madv_pageout.patch Just for the record Acked-by: Michal Hocko And thanks for syzkaller to exercise the new interface so quickly! > Signed-off-by: Minchan Kim > --- > mm/vmscan.c | 1 + > 1 file changed, 1 insertion(+) > > diff --git a/mm/vmscan.c b/mm/vmscan.c > index 47aa2158cfac2..e2a8d3f5bbe48 100644 > --- a/mm/vmscan.c > +++ b/mm/vmscan.c > @@ -2181,6 +2181,7 @@ unsigned long reclaim_pages(struct list_head *page_list) > } > > if (nid == page_to_nid(page)) { > + ClearPageActive(page); > list_move(&page->lru, &node_page_list); > continue; > } > -- > 2.22.0.770.g0f2c4a37fd-goog -- Michal Hocko SUSE Labs