From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CDAF02931EA for ; Tue, 11 Aug 2026 00:48:53 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786409335; cv=none; b=uy+EEwRmaLC2PkIT5m+j9rg83WRZvv41l2ixIiBE0PlFlUVpguIgBLkLh3YLOEZTz+v2oAQiXkUTj9kpSuDhDRGmSKZHiXCH9kbmAsjGQW8kw/t4ILbNHRye0xrUgcWeIuVXphef50PFV7umv7EGMtF3wJFEFni//Ik05+XzDpY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786409335; c=relaxed/simple; bh=spGCxb7RU+6C9cPnSHzYjDGa2aAIO7fllOtDLI/Abpk=; h=Date:From:To:Cc:Subject:Message-Id:In-Reply-To:References: Mime-Version:Content-Type; b=hRql7YxRfV4vKW9rAqXgk0RztkvQVMkqr4MhgmHPzDZQjiMKtEhCdEDjHoS5onCr9MKePNk3lNNXy0PcC4ZeziftFSEqVzHnIgJHQUGqX5ZPS+9t7R/tEoVTmrEXrqKq9Rg56UQRpQV793QV3iR9tehH3V4YbE3E7STbi0DN6D0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=QsjsG/IQ; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="QsjsG/IQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF14C1F000E9; Tue, 11 Aug 2026 00:48:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1786409333; bh=ULPNoA98k1MGbNwPUHP+7eh68YMauJgzPpcaDil/e2k=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=QsjsG/IQ4QSsXLetYPhTu56p5S/IkYcP6MgBGAePoP38AQwk3upCTYKfqXaZhndxS FxhCbJRXJ5Eg0w0fIF8Yyet+OHPjffGrUDQrwDEsYy+CO52zsI95M+zlioimW4qz10 7K89jETg9le3bGYk7OweqtTmGoM21SxB4YHKVrLI= Date: Mon, 10 Aug 2026 17:48:52 -0700 From: Andrew Morton To: syzbot Cc: axelrasmussen@google.com, baohua@kernel.org, david@kernel.org, hannes@cmpxchg.org, kasong@tencent.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, ljs@kernel.org, mhocko@kernel.org, qi.zheng@linux.dev, shakeel.butt@linux.dev, syzkaller-bugs@googlegroups.com, weixugc@google.com, yuanchu@google.com. R: Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu Subject: Re: [syzbot] [mm?] WARNING in set_mm_walk Message-Id: <20260810174852.aca0f73ab7ad71c70dcdefda@linux-foundation.org> In-Reply-To: <6a7a6929.b50370da.49fe0.005e.GAE@google.com> References: <6a7a6929.b50370da.49fe0.005e.GAE@google.com> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Mon, 10 Aug 2026 17:13:29 -0700 syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 562bfb501c54 Merge tag 'integrity-v7.2-rc7' of git://git.k.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=11a8cbb9580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=145fa60d73086782 > dashboard link: https://syzkaller.appspot.com/bug?extid=12ee2725d5fde63a9c96 > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 Thanks. One for the MGLRU develoeprs, it seems. https://share.gemini.google/Wg4a5ns7E0LF might save a bit of time figuring this out. > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/d900f083ada3/non_bootable_disk-562bfb50.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/9cbf6ef0490e/vmlinux-562bfb50.xz > kernel image: https://storage.googleapis.com/syzbot-assets/7ee52864c79a/bzImage-562bfb50.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+12ee2725d5fde63a9c96@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > current_is_kswapd() > WARNING: mm/vmscan.c:3800 at set_mm_walk+0x210/0x270 mm/vmscan.c:3800, CPU#1: kswapd0/110 > > Modules linked in: > CPU: 1 UID: 0 PID: 110 Comm: kswapd0 Tainted: G L syzkaller #0 PREEMPT(full) > Tainted: [L]=SOFTLOCKUP > Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 > RIP: 0010:set_mm_walk+0x210/0x270 mm/vmscan.c:3800 > Code: 13 00 00 4d 8d 7d 08 e9 f7 fe ff ff e8 79 f5 2a 00 e9 b7 fe ff ff e8 7f 6b ba ff 90 0f 0b 90 e9 d2 fe ff ff e8 71 6b ba ff 90 <0f> 0b 90 e9 74 ff ff ff 4c 89 ff e8 80 f5 2a 00 e9 4e fe ff ff 48 > RSP: 0018:ffffc900027772b8 EFLAGS: 00010293 > RAX: 0000000000000000 RBX: ffff888024934a80 RCX: ffffffff824ff8e8 > RDX: ffff888024934a80 RSI: ffffffff824ff96f RDI: ffff888024934a80 > RBP: 0000000000020000 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000000020000 R11: 0000000000000000 R12: 0000000000000000 > R13: ffffc90002777c38 R14: 0000000000000001 R15: ffffc90002777c40 > FS: 0000000000000000(0000) GS:ffff8880d5ed8000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000001b31923ffc CR3: 0000000109695000 CR4: 0000000000352ef0 > DR0: 0000000000000005 DR1: 0000000000000005 DR2: 0000000020040004 > DR3: 0000000000000056 DR6: 00000000ffff0ff0 DR7: 0000000000000400 > Call Trace: > > try_to_inc_max_seq+0xf0/0x1090 mm/vmscan.c:4023 > try_to_shrink_lruvec+0x4bd/0x6b0 mm/vmscan.c:4977 > lru_gen_shrink_lruvec mm/vmscan.c:5128 [inline] > shrink_lruvec+0x31e/0x25b0 mm/vmscan.c:5888 > mem_cgroup_shrink_node+0x227/0x6a0 mm/vmscan.c:6753 > mem_cgroup_soft_reclaim mm/memcontrol-v1.c:312 [inline] > memcg1_soft_limit_reclaim+0x2d5/0x830 mm/memcontrol-v1.c:362 > balance_pgdat+0xa11/0x1f00 mm/vmscan.c:7177 > kswapd+0x556/0xb50 mm/vmscan.c:7462 > kthread+0x370/0x450 kernel/kthread.c:436 > ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 > ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 > > > > --- > This report is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this issue. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > > If the report is already addressed, let syzbot know by replying with: > #syz fix: exact-commit-title > > If you want to overwrite report's subsystems, reply with: > #syz set subsystems: new-subsystem > (See the list of subsystem names on the web dashboard) > > If the report is a duplicate of another one, reply with: > #syz dup: exact-subject-of-another-report > > If you want to undo deduplication, reply with: > #syz undup