From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f53.google.com (mail-ot1-f53.google.com [209.85.210.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AFBC43AE6E0 for ; Mon, 9 Feb 2026 18:50:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770663005; cv=none; b=kMU52SwwEeX9l5/nD+L5GURml7OEkPbni0pUG26M9nbI2RpKCdl+W0RryhycjehkmOrvmeuQ+gBkKjfjE4au0YnSyq7JksoZe+KNfYZdlyS+Ex3/p+BJ7VCH2LYKqYFTpg5KNRA68HBimnVDQ1ep+j6LFvMfRDvSCIG80+ngbl4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770663005; c=relaxed/simple; bh=undCIAWo6qWW+Z1HOg8qlP6+G1FkpCs7G0WeQTxNGE4=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=s9ZzmfbXm5ZW/b4jwpKnliDwz8SEWTYrOwnp1IOoHHxG9IgFhUtI8PRmgEcrU+RYQoKswOhTIdKCY1Ap4GZz7dUhPsx3yu/l+1wSoJU9lAGd48ItdJp5fauR55mrbLN/Qkpwtj0np88IszJDiiQ1Dz+SCq/Af3j/TsoVD3C5Exc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk; spf=pass smtp.mailfrom=kernel.dk; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b=t4/LgPMQ; arc=none smtp.client-ip=209.85.210.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.dk Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.dk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel-dk.20230601.gappssmtp.com header.i=@kernel-dk.20230601.gappssmtp.com header.b="t4/LgPMQ" Received: by mail-ot1-f53.google.com with SMTP id 46e09a7af769-7cfd9b898cdso34797a34.2 for ; Mon, 09 Feb 2026 10:50:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20230601.gappssmtp.com; s=20230601; t=1770663004; x=1771267804; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id:from :to:cc:subject:date:message-id:reply-to; bh=tYxV1ZZhF0FuP950hVsE38NKjm5LJ2udmADunvWNt+s=; b=t4/LgPMQIOf+ZNB3uBDthKw6azftbW9Btm5KFt8VuvCRJlmSCyP7PJFnrf1XzCiHgQ YzD7zsorl3YdHXqFGjDkQiUQSY53Mac1ESu9I/DOpfyFhd/1SPkzlD5XaLpzYydYgeZY DtDVAQGA6Bq27AXMgZV5m6SC2kjYaCBlgHfIWQ+OPh7npVtRVN+OAtdpt4ApvXXroeql Pc52RomB99ti17lhu5cka7t7DwpZM/ZWetwWLgBWE2tV+emF0orVSHfGaywibOAO+seU ZSfR9x2MN1cBwslC9NfaHngbBhthvlcmpJEEvH9yhrfewRdGZbMIJBFaR17NolrmxuTW Nxbg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770663004; x=1771267804; h=content-transfer-encoding:in-reply-to:from:content-language :references:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=tYxV1ZZhF0FuP950hVsE38NKjm5LJ2udmADunvWNt+s=; b=otw6LEvcDdEcFpsTDm1e7PMRKHXpLUz4JwPOgiWKvgknZmXBzcpxDPzRpgSHXllfLJ 2xYnWUmnGtk8moHhPRH5vVVVdjbyh0Jp2gBn7sgzBgbq+jffDNqhW0dYBz/tuDCoS6QP s4ZFImkv7Mn94oUalxC/B7klUap6Qvhxq3jY27iJE3tO7BtxZSutwF0SlGptfRsSQ3d/ ZVNCcgWZ7KWMvb78U2Kasql4umdxHKEYx1lRxVwH1yAUTzVl/r8nJOegzMepi//FxU9G LWUjCOu8NEYT4J8KisuKAa6a+/6hLZNruLVO8PtYl/0L7ARRzQ0dxc5Kk7X1RvIb/vsm beEg== X-Forwarded-Encrypted: i=1; AJvYcCVZKAhcAxU6Q81k+vEZ+/8NXXFQ6SgrjNzpAkp5xHH3QDacKCAmGoJbM3vYxd2x63tp3+bjJK66Kg==@vger.kernel.org X-Gm-Message-State: AOJu0Yzrc7FhbSjVnhr9/1pRyqRg78Orna7/iVTxSOR6sk+rtNFW5P1+ gwdQApMqV9lkL3B1FRc9Ph7CVhU3hOv5rM0DWyvYJIJ/y43Xhgo+4DWUndDkO8P4/UToEq9SADf FK9jIaa4= X-Gm-Gg: AZuq6aK4v5nV4d40CVgdrH3roOcMZtjjl0P92Nju/vZhwubEr+mFx7lXXq7OdijMJYu w2bQBcXVoyPbMjkqDd9YbdxIcIhPrIEPnFiMliocilH7a9YHbzDAJZ9BlzCQCFATFnRgzl8A0cI 8sbtU+R3/euehD+1vr5+VbRz/ccrinVDmkXJvDDGFMzZSe37tHdlefJuLN6gp6u+YhIclKvvb9m 0rVZqCs4ofwmZ8E3vHYruG3HoaO+98EUd1Z/0HVs2OU135hxYVALXdyOGCyBQ9/Alg6w11Yk+7o Q+mMfcl0A7kv35+x7m9dWJfVIQ8LhP6X8GSF+dYagnpkavaZTRsBHshF60EMmX0CwRUKYE+ipKy e/+0EarTjpVJUtNZTgJY8A8zkZQdXHSgpwd9rDJeJdu91Du7BS4znlBkObgX/E9UQiH/qYTC5pw Tao+EgYIO8Y6QzFBP+h6dSygdHokCkaYWU/lG8Lnt8e9AaVB6D6nCb0fzIKXVDt26K16ME1Q== X-Received: by 2002:a05:6830:6994:b0:79c:f9ff:43e with SMTP id 46e09a7af769-7d46467e812mr6111729a34.28.1770663003431; Mon, 09 Feb 2026 10:50:03 -0800 (PST) Received: from [192.168.1.150] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id 46e09a7af769-7d4647277a4sm7929198a34.13.2026.02.09.10.50.02 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 09 Feb 2026 10:50:02 -0800 (PST) Message-ID: Date: Mon, 9 Feb 2026 11:50:02 -0700 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [syzbot] [io-uring?] BUG: corrupted list in io_poll_remove_entries To: syzbot , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, Mauro Carvalho Chehab , linux-media@vger.kernel.org References: <698a26d3.050a0220.3b3015.007d.GAE@google.com> Content-Language: en-US From: Jens Axboe In-Reply-To: <698a26d3.050a0220.3b3015.007d.GAE@google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 2/9/26 11:26 AM, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: e7aa57247700 Merge tag 'spi-fix-v6.19-rc8' of git://git.ke.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=14d3b65a580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=f1fac0919970b671 > dashboard link: https://syzkaller.appspot.com/bug?extid=ab12f0c08dd7ab8d057c > compiler: gcc (Debian 14.2.0-19) 14.2.0, GNU ld (GNU Binutils for Debian) 2.44 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1222965a580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=140e833a580000 > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/c46beb4ff3a5/disk-e7aa5724.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/d162bcaaf9b9/vmlinux-e7aa5724.xz > kernel image: https://storage.googleapis.com/syzbot-assets/54b0844b8ea7/bzImage-e7aa5724.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ab12f0c08dd7ab8d057c@syzkaller.appspotmail.com > > list_del corruption. prev->next should be ffff88807dc6c3f0, but was ffff888146b205c8. (prev=ffff888146b205c8) > ------------[ cut here ]------------ > kernel BUG at lib/list_debug.c:62! > Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI > CPU: 0 UID: 0 PID: 5969 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full) > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 > RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62 > Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 3d fa 8b e8 37 b0 32 fc 90 <0f> 0b 4c 89 e7 e8 3c 24 5d fd 48 89 ea 48 b8 00 00 00 00 00 fc ff > RSP: 0018:ffffc90003bffaa8 EFLAGS: 00010082 > RAX: 000000000000006d RBX: ffff88807dc6c3f0 RCX: 0000000000000000 > RDX: 000000000000006d RSI: ffffffff81e5d6c9 RDI: fffff5200077ff46 > RBP: ffff888146b205c8 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000080000001 R11: 0000000000000000 R12: ffff88807dc6c2b0 > R13: ffff88807dc6c408 R14: ffff88807dc6c3f0 R15: ffff88807dc6c3c8 > FS: 0000000000000000(0000) GS:ffff8881245d9000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f60e56708c0 CR3: 000000006b065000 CR4: 00000000003526f0 > Call Trace: > > __list_del_entry_valid include/linux/list.h:132 [inline] > __list_del_entry include/linux/list.h:223 [inline] > list_del_init include/linux/list.h:295 [inline] > io_poll_remove_waitq io_uring/poll.c:149 [inline] > io_poll_remove_entry io_uring/poll.c:166 [inline] > io_poll_remove_entries.part.0+0x156/0x7e0 io_uring/poll.c:197 > io_poll_remove_entries io_uring/poll.c:177 [inline] > io_poll_task_func+0x39e/0xe30 io_uring/poll.c:343 > io_handle_tw_list+0x194/0x580 io_uring/io_uring.c:1122 > tctx_task_work_run+0x57/0x2b0 io_uring/io_uring.c:1182 > tctx_task_work+0x7a/0xd0 io_uring/io_uring.c:1200 > task_work_run+0x150/0x240 kernel/task_work.c:233 > exit_task_work include/linux/task_work.h:40 [inline] > do_exit+0x829/0x2a30 kernel/exit.c:971 > do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 > __do_sys_exit_group kernel/exit.c:1123 [inline] > __se_sys_exit_group kernel/exit.c:1121 [inline] > __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1121 > x64_sys_call+0x14fd/0x1510 arch/x86/include/generated/asm/syscalls_64.h:232 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f60e579aeb9 > Code: Unable to access opcode bytes at 0x7f60e579ae8f. > RSP: 002b:00007ffc2d47ddf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f60e579aeb9 > RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f60e59e1280 > R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007f60e59e1280 R14: 0000000000000003 R15: 00007ffc2d47deb0 > > Modules linked in: > ---[ end trace 0000000000000000 ]--- > RIP: 0010:__list_del_entry_valid_or_report+0x14a/0x1d0 lib/list_debug.c:62 > Code: 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 8d 00 00 00 48 8b 55 00 48 89 e9 48 89 de 48 c7 c7 40 3d fa 8b e8 37 b0 32 fc 90 <0f> 0b 4c 89 e7 e8 3c 24 5d fd 48 89 ea 48 b8 00 00 00 00 00 fc ff > RSP: 0018:ffffc90003bffaa8 EFLAGS: 00010082 > RAX: 000000000000006d RBX: ffff88807dc6c3f0 RCX: 0000000000000000 > RDX: 000000000000006d RSI: ffffffff81e5d6c9 RDI: fffff5200077ff46 > RBP: ffff888146b205c8 R08: 0000000000000005 R09: 0000000000000000 > R10: 0000000080000001 R11: 0000000000000000 R12: ffff88807dc6c2b0 > R13: ffff88807dc6c408 R14: ffff88807dc6c3f0 R15: ffff88807dc6c3c8 > FS: 0000000000000000(0000) GS:ffff8881245d9000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f60e56708c0 CR3: 000000006b065000 CR4: 00000000003526f0 This looks like a bug related to dvb polling, presumably in dvb_dvr_poll() or friends. I've seen that in drivers before, for example comedi, see: commit 35b6fc51c666fc96355be5cd633ed0fe4ccf68b2 Author: Ian Abbott Date: Tue Jul 22 16:53:16 2025 +0100 comedi: fix race between polling and detaching as a reference. #syz set subsystems: media -- Jens Axboe