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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 96FC1C433EF for ; Wed, 27 Apr 2022 17:20:37 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 01D426B0071; Wed, 27 Apr 2022 13:20:37 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EE6E56B0073; Wed, 27 Apr 2022 13:20:36 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id D60986B0074; Wed, 27 Apr 2022 13:20:36 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id BF2D16B0071 for ; Wed, 27 Apr 2022 13:20:36 -0400 (EDT) Received: from smtpin13.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id 7648F21499 for ; Wed, 27 Apr 2022 17:20:36 +0000 (UTC) X-FDA: 79403323272.13.7AD552B Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by imf18.hostedemail.com (Postfix) with ESMTP id 405341C0055 for ; Wed, 27 Apr 2022 17:20:30 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id E76E761E26; Wed, 27 Apr 2022 17:20:33 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E21BC385A9; Wed, 27 Apr 2022 17:20:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1651080033; bh=mDxN/hweypMYCBUL2KTZy6C5KMIYEDI13Bz4xMkwNDU=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=AoM1WRvT7cRcSrN0EOxDpCyVFb7ymWjxKqBmTt9nSNf1P4fP+LOxH0x+70x6jYXTU +U9ltjHvwvISMNfCQN5WceOEYRLJkxtbyiQ0ZUw8I+C5Wqev+00Ixfw7B8RsV2iStJ RTkd7HooRBX1YG9qHsQbx/ToaPrlss2ZOWiy85aY= Date: Wed, 27 Apr 2022 10:20:32 -0700 From: Andrew Morton To: syzbot Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, syzkaller-bugs@googlegroups.com, Liam Howlett , Peter Xu Subject: Re: [syzbot] WARNING in vma_merge Message-Id: <20220427102032.5a87283eb64d06c1a6d682fd@linux-foundation.org> In-Reply-To: <000000000000f28f0005dda29992@google.com> References: <000000000000a23c8505dda227eb@google.com> <000000000000f28f0005dda29992@google.com> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Authentication-Results: imf18.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=AoM1WRvT; dmarc=none; spf=pass (imf18.hostedemail.com: domain of akpm@linux-foundation.org designates 139.178.84.217 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: 405341C0055 X-Rspam-User: X-Stat-Signature: 7i1kwptfuzaku6cimnc8btmray3nre95 X-HE-Tag: 1651080030-145950 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: On Wed, 27 Apr 2022 06:15:20 -0700 syzbot wrote: > syzbot has found a reproducer for the following issue on: Thanks. userfaultfd_release() appears to have offended vma_merge(). I'm not seeing any changes in that area from Peter, but Liam's mapletree work changed things around a bit. Gents, could you please take a look? > HEAD commit: f02ac5c95dfd Add linux-next specific files for 20220427 > git tree: linux-next > console output: https://syzkaller.appspot.com/x/log.txt?x=105a33a2f00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=e9256c70f586da8a > dashboard link: https://syzkaller.appspot.com/bug?extid=7728e4ab5371cebc9c00 > compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15f76f82f00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12b42c3cf00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+7728e4ab5371cebc9c00@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 3593 at mm/mmap.c:1072 vma_merge+0x428/0x950 mm/mmap.c:1072 I assume this is VM_WARN_ON(area && end > area->vm_end); But lines change around a lot. It would be great if the script which generates these reports could quote the code around the indicated file and line. Like: next = find_vma(mm, prev ? prev->vm_end : 0); area = next; if (area && area->vm_end == end) /* cases 6, 7, 8 */ next = find_vma(mm, next->vm_end); /* verify some invariant that must be enforced by the caller */ VM_WARN_ON(prev && addr <= prev->vm_start); --> VM_WARN_ON(area && end > area->vm_end); VM_WARN_ON(addr >= end); /* * Can it merge with the predecessor? */ if (prev && prev->vm_end == addr && > Modules linked in: > CPU: 1 PID: 3593 Comm: syz-executor549 Not tainted 5.18.0-rc4-next-20220427-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:vma_merge+0x428/0x950 mm/mmap.c:1072 > Code: 00 e8 5c 1f c4 ff e8 57 1f c4 ff 45 31 f6 e8 4f 1f c4 ff 4c 89 f0 48 83 c4 28 5b 5d 41 5c 41 5d 41 5e 41 5f c3 e8 38 1f c4 ff <0f> 0b e9 6c fd ff ff e8 2c 1f c4 ff 48 8d bd 88 00 00 00 48 b8 00 > RSP: 0018:ffffc90002edfd10 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: 0000000008102073 RCX: 0000000000000000 > RDX: ffff88801d0a3a80 RSI: ffffffff81b62968 RDI: 0000000000000003 > RBP: ffff88807e550bd0 R08: 0000000021001000 R09: 0000000000000000 > R10: ffffffff81b626ce R11: 0000000000000000 R12: 0000555557211000 > R13: 00005555571ef000 R14: ffff88807e550d80 R15: ffff88807e550d80 > FS: 00005555571ef300(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00005564400b0df0 CR3: 0000000073d7f000 CR4: 00000000003506e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > > mlock_fixup+0x349/0x7f0 mm/mlock.c:420 > apply_mlockall_flags+0x2be/0x440 mm/mlock.c:691 > __do_sys_mlockall+0x222/0x4b0 mm/mlock.c:719 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x44/0xae > RIP: 0033:0x7f9cdd5a1f99 > Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007ffecfa63c98 EFLAGS: 00000246 ORIG_RAX: 0000000000000097 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9cdd5a1f99 > RDX: 00007f9cdd5a1f99 RSI: 0000000000000000 RDI: 0000000000000003 > RBP: 00007f9cdd565f80 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9cdd566010 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 >