From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f71.google.com (mail-oo1-f71.google.com [209.85.161.71]) (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 9DDC13D3335 for ; Wed, 25 Feb 2026 14:15:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.71 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772028905; cv=none; b=TrbGCD/9AuMwSAhI4xmocm6DI/JN4/ZXI34yMvnQ9qT5XlrPByKlB8m39lwHSiIQz6fQ/h7NKJTBbGgnF/+ev3ExKRbgxENaxOGBE7VRcipyuCf3dBSsbsCXVp6YFTEdHw4MxpPBGFGedrtK/pHVEaVOGTiaFMF95nbhHvyOwJs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772028905; c=relaxed/simple; bh=gYESzHiAyJR3P1/mPS6MuQzzEW7AVSViXYnN3RkGB8A=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=kG6UWf6qPP9SXJ5UaJUFLlLWrl+OKQA7GtzjZOyfBp7awYueG2EKg3NN8+i3CU2josWxLJvdRDxnpqSRglC+Naqt2RykM6r26ru+rnnfBnxQJggrKpAonigJhNBtwNIKUFpOQzDueQjFXfVac6EUoIpYCkTxIew+uITlAtULPZ8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.161.71 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-oo1-f71.google.com with SMTP id 006d021491bc7-679caf7ec07so56302531eaf.1 for ; Wed, 25 Feb 2026 06:15:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1772028902; x=1772633702; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=x1GzfhVMwaSGdQ/2PeOU85IAixqTpZO5TnKOGP6CCTA=; b=sBJk1xrlEsQT8jhfLM8rnHmjv+QXMM4RVxL1BEnW28Fov2kwy6DsHS4qdcl5ndvG4L wf7jsIoDZSxe5Pof8sQ4EyB1zFrecubnu0x0hTXBUAaSyZh2ANB9qEoY+EKfyHbXtCA0 YFg4VYE2ZIFJPhsdpiDgpXZdGW8RvclllaPZg6BWEJZh2PA/Sh3NBkp0H7Pi+Rd/ozww DE7kAJTAYPPCae5Thq2g0j/5oZPWq55FnEeqEGWzi+P+/8lSfTdSdjsp0579G6DZh0fJ tGiLnrCRqNRghNpJfo/SDZ4SHc+AkOFIYB8CGHqjI9NMoJNnlS3Tfg6tLknH93FtdmOk zaJQ== X-Forwarded-Encrypted: i=1; AJvYcCXN6N2upSHe7EBYFbc4FlHMrezp3Jch3foqV++98/G2Utj6qVDrDJTuTAEkjD9eXRkchGFVwHeDUhw7glA=@vger.kernel.org X-Gm-Message-State: AOJu0Yyaj+/SbojEZhFCkJbzW/vOzs06Z/DVulMVeAZLUpFT7RTqIEeP c1TyQ/b3guEUKVzpVzFtHqG3j+z0nqsozzdYpPMlMlCcAaBPjPJ097aMXC5u9irj2bhnSL/Onng uURlrA6egXc3aluC0BOCBGlRABMYGrqB2G211BzRQpxZpZ7yMHq/zAfywJfA= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:4810:b0:677:e168:3f57 with SMTP id 006d021491bc7-679c425e825mr6883516eaf.4.1772028902435; Wed, 25 Feb 2026 06:15:02 -0800 (PST) Date: Wed, 25 Feb 2026 06:15:02 -0800 In-Reply-To: <20260225122110.463-1-hdanton@sina.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <699f03e6.a00a0220.21906d.000d.GAE@google.com> Subject: Re: [syzbot] [lsm] [kernel] INFO: task hung in restrict_one_thread_callback From: syzbot To: hdanton@sina.com, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: INFO: task hung in landlock_restrict_sibling_threads INFO: task syz.0.146:6909 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.146 state:D stack:28832 pid:6909 tgid:6908 ppid:6445 task_flags:0x400140 flags:0x00080006 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 landlock_restrict_sibling_threads+0xf3d/0x11f0 security/landlock/tsync.c:549 __do_sys_landlock_restrict_self security/landlock/syscalls.c:574 [inline] __se_sys_landlock_restrict_self+0x540/0x810 security/landlock/syscalls.c:482 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f81f479bf79 RSP: 002b:00007f81f559d028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f81f4a15fa0 RCX: 00007f81f479bf79 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000003 RBP: 00007f81f48327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f81f4a16038 R14: 00007f81f4a15fa0 R15: 00007ffd3d3acd98 INFO: task syz.0.146:6910 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.146 state:D stack:28616 pid:6910 tgid:6908 ppid:6445 task_flags:0x400140 flags:0x00080006 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 landlock_restrict_sibling_threads+0xf3d/0x11f0 security/landlock/tsync.c:549 __do_sys_landlock_restrict_self security/landlock/syscalls.c:574 [inline] __se_sys_landlock_restrict_self+0x540/0x810 security/landlock/syscalls.c:482 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f81f479bf79 RSP: 002b:00007f81f557c028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f81f4a16090 RCX: 00007f81f479bf79 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000003 RBP: 00007f81f48327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f81f4a16128 R14: 00007f81f4a16090 R15: 00007ffd3d3acd98 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e9602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 5 locks held by kworker/u8:6/411: 2 locks held by getty/5575: #0: ffff888036de80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 411 Comm: kworker/u8:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: 0x0 (events_unbound) RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_is_held_type+0xda/0x150 kernel/locking/lockdep.c:5941 Code: f9 eb cb 31 db eb 1c 83 fd ff 74 12 31 c0 f6 43 22 03 0f 95 c0 31 db 39 c5 0f 94 c3 eb 05 bb 01 00 00 00 48 c7 c7 0f 1d 28 8e 21 18 00 00 b8 ff ff ff ff 65 0f c1 05 04 f0 88 07 83 f8 01 75 RSP: 0018:ffffc900034afa88 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000001 RDX: 0000000000000000 RSI: ffffffff8e028949 RDI: ffffffff8e281d0f RBP: 00000000ffffffff R08: ffffffff903384b7 R09: 1ffffffff2067096 R10: dffffc0000000000 R11: fffffbfff2067097 R12: 0000000000000246 R13: ffff888024c8dac0 R14: ffffffff8e9603a0 R15: 1ffff110170e75b3 FS: 0000000000000000(0000) GS:ffff888125311000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055558fd504e8 CR3: 000000000e74c000 CR4: 00000000003526f0 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] schedule_debug kernel/sched/core.c:5874 [inline] __schedule+0x262/0x5340 kernel/sched/core.c:6783 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 worker_thread+0xc1e/0xfc0 kernel/workqueue.c:3454 kthread+0x388/0x470 kernel/kthread.c:467 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Tested on: commit: 7dff99b3 Remove WARN_ALL_UNSEEDED_RANDOM kernel config.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11e97c4a580000 kernel config: https://syzkaller.appspot.com/x/.config?x=56c0294cb1688557 dashboard link: https://syzkaller.appspot.com/bug?extid=7ea2f5e9dfd468201817 compiler: Debian clang version 21.1.8 (++20251221033036+2078da43e25a-1~exp1~20251221153213.50), Debian LLD 21.1.8 patch: https://syzkaller.appspot.com/x/patch.diff?x=13c17c4a580000