From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-141.sina.com.cn (smtp153-141.sina.com.cn [61.135.153.141]) (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 563D51B960 for ; Fri, 15 Aug 2025 00:17:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.141 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755217030; cv=none; b=ByX6UXnnRAg38tTs0WvtJKbYezUJyfwPdkG1dyPeWW750ileT4GbRlkIP51v7kHe96djhQnt7DwNPOOW3jriA/uFRlbLvZ/RaO4CP6OMEynk06PhAjZRbnTSx1ItxE9i+lWP5WvMjQGZ0XGxPaxxB03woX4gpTO/OUBUKotkpqs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755217030; c=relaxed/simple; bh=M7/awrwFW0+lfKMbyVgOnxo2z+jj8zWoxElZ250hLBY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tthmgjdlszbpBfjHi9cOO9sczwCRx9JINz4ri3Mf0l9bWmKaNR2quxbBxyVOxdLodzxc0craLDXdWeTv6d3YjUJXiLkHRB0Ku8E1D5CZ6I8daHHimMu6O59xOxQpa+w5ykaDIruF8Z6DR5kXofY3Nn5Iv+fx+4LD+/lzw49oRsA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=EaBfpehO; arc=none smtp.client-ip=61.135.153.141 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="EaBfpehO" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1755217022; bh=fDqRyFA+mjlN2QT1Fq9xh052KYDrnE6/QdvHVjXFdsg=; h=From:Subject:Date:Message-ID; b=EaBfpehO+1zlm7YJwztOIchQAZtL1NeIiAw715OCpq9hN72Sn7s/KXnV4JdYSMfdH OcJLdevk5GdEkwz3Xt4AnYW+HQtLeI/kHJvmgGh91NhOnBTxW15hJRfA+A1KxQkdVT 2lhaFIV3+wSN2bPjJSTwRsbh7QKoxNG5Yh4hz3js= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.31) with ESMTP id 689E7B3300004D9A; Fri, 15 Aug 2025 08:11:34 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 1152966816373 X-SMAIL-UIID: B585CA0F583C4A35B1986E2EFF5354D0-20250815-081134-1 From: Hillf Danton To: syzbot Cc: edumazet@google.com, linux-kernel@vger.kernel.org, Krzysztof Kozlowski , Thomas Gleixner , Tetsuo Handa , netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [nfc?] [net?] WARNING in nfc_rfkill_set_block Date: Fri, 15 Aug 2025 08:11:21 +0800 Message-ID: <20250815001123.4558-1-hdanton@sina.com> In-Reply-To: <689e6bba.050a0220.e29e5.0003.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 14 Aug 2025 16:05:30 -0700 > Hello, > > syzbot found the following issue on: > > HEAD commit: 8f5ae30d69d7 Linux 6.17-rc1 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=16c80af0580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=13f39c6a0380a209 > dashboard link: https://syzkaller.appspot.com/bug?extid=535bbe83dfc3ae8d4be3 > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 > > Unfortunately, I don't have any reproducer for this issue yet. > > Downloadable assets: > disk image: https://storage.googleapis.com/syzbot-assets/46150b6d2447/disk-8f5ae30d.raw.xz > vmlinux: https://storage.googleapis.com/syzbot-assets/1c604b2b2258/vmlinux-8f5ae30d.xz > kernel image: https://storage.googleapis.com/syzbot-assets/9c542f0972de/bzImage-8f5ae30d.xz > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+535bbe83dfc3ae8d4be3@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > rtmutex deadlock detected Even given the lockdep_set_novalidate_class() in device_initialize(), rtmutex can detect deadlock (the ABBA one [1]?), weird. [1] Subject: [PATCH] net/nfc: Fix A-B/B-A deadlock between nfc_unregister_device and rfkill_fop_write https://lore.kernel.org/lkml/20250814173142.632749-2-ysk@kzalloc.com/ > WARNING: CPU: 1 PID: 9725 at kernel/locking/rtmutex.c:1674 rt_mutex_handle_deadlock+0x28/0xb0 kernel/locking/rtmutex.c:1674 > Modules linked in: > CPU: 1 UID: 0 PID: 9725 Comm: syz.8.874 Tainted: G W 6.17.0-rc1-syzkaller #0 PREEMPT_{RT,(full)} > Tainted: [W]=WARN > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 > RIP: 0010:rt_mutex_handle_deadlock+0x28/0xb0 kernel/locking/rtmutex.c:1674 > Code: 90 90 41 57 41 56 41 55 41 54 53 83 ff dd 0f 85 8c 00 00 00 48 89 f7 e8 c6 2c 01 00 90 48 c7 c7 a0 08 0b 8b e8 79 08 8b f6 90 <0f> 0b 90 90 4c 8d 3d 00 00 00 00 65 48 8b 1c 25 08 b0 f5 91 4c 8d > RSP: 0018:ffffc900043a7950 EFLAGS: 00010246 > RAX: 89021558f1df5a00 RBX: ffffc900043a79e0 RCX: ffff888025bb3b80 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: ffffc900043a7b00 R08: 0000000000000000 R09: 0000000000000000 > R10: dffffc0000000000 R11: ffffed1017124863 R12: 1ffff92000874f38 > R13: ffffffff8af82119 R14: ffff888036e55098 R15: dffffc0000000000 > FS: 00007fec70d5e6c0(0000) GS:ffff8881269c5000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007fce013b0000 CR3: 000000003ebbc000 CR4: 00000000003526f0 > Call Trace: > > __rt_mutex_slowlock kernel/locking/rtmutex.c:1734 [inline] > __rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline] > rt_mutex_slowlock+0x692/0x6e0 kernel/locking/rtmutex.c:1800 > __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] > __mutex_lock_common kernel/locking/rtmutex_api.c:536 [inline] > mutex_lock_nested+0x16a/0x1d0 kernel/locking/rtmutex_api.c:547 > device_lock include/linux/device.h:911 [inline] > nfc_dev_down net/nfc/core.c:143 [inline] > nfc_rfkill_set_block+0x50/0x2e0 net/nfc/core.c:179 > rfkill_set_block+0x1e5/0x450 net/rfkill/core.c:346 > rfkill_fop_write+0x44e/0x580 net/rfkill/core.c:1301 > vfs_write+0x287/0xb40 fs/read_write.c:684 > ksys_write+0x14b/0x260 fs/read_write.c:738 > do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] > do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7fec72afebe9 > Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007fec70d5e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 00007fec72d25fa0 RCX: 00007fec72afebe9 > RDX: 0000000000000008 RSI: 0000200000000080 RDI: 0000000000000003 > RBP: 00007fec72b81e19 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007fec72d26038 R14: 00007fec72d25fa0 R15: 00007ffe1f71d718 > > > > --- > 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 >