From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-oo1-f72.google.com (mail-oo1-f72.google.com [209.85.161.72]) (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 9F1E034166B for ; Fri, 20 Feb 2026 11:11:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.161.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771585884; cv=none; b=r31n5zm5AaVkO/Kqd0K1b3bhLCjK+ittwSktOzTyRpoD4yVLtmNamaVoaUZopS/Z5jgPgpsI0ZEf9ETAFoPhKBFypCYMiwnzdEeFyGvZDrFSzQ0/I7ZZaO3XZNfRIWuwC+PlyRjuk9DK7QL6361bEdhl9jtlCePttKaRCCcvs90= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771585884; c=relaxed/simple; bh=Nc79mmAJKSdAQ9gZPCQT45QDQAQB6DrIfibrXqjNJ1w=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=mi3tz2Z6YV84QDBjTclaOBlZOMEzWLXlHrbAoUGpGpBnfE/GE+/MiLamaQp2SGkh54UBo8+BHd9dgEhrZkLplR5RMcYAfkOBLpDigrNipfDMkwg8PY5YrVGfEXhdS2MlXtcJEKFMZ5jRGIjiGV6pN9Qx5ozntZ5g31ShxXS14ww= 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=209.85.161.72 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-f72.google.com with SMTP id 006d021491bc7-6787fa20d41so30031774eaf.0 for ; Fri, 20 Feb 2026 03:11:22 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1771585881; x=1772190681; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=StCC4KLNTBEre8TLHWqJ6e4A2/9P/xnnZcl5tIfr5S0=; b=kusgZ1OtGv/dCd78U3IfW5NdIEAG3b43vNMLk4RPN2O9mllwSWqw1nuGIlXiXDTfkG QHTTjTCRgaO++Pi8P0iaBJ8F/MaXrrA9cD/95sqoGmG2SRq3jD5IwS1nBldmNdL+UE4i EXLQ7pIATPPSr7UUDZEqxowaRagjRSb+PVLgyoI4Vob3tZSf6wx+m+1IR0VNIxAM77Ox IajYj2EJMcM9Zo5YM7/s9iVrUsG0LEYdbYlfNNOAkMCvt1nX59IgkC5tCzDi94UEa7Mk /RJlYwMhhex3y5LfptU6RY1bcdPar0P5TSIcsGJU4e4fZxNai6s1VCTslFFQN7M5hSGc r4iA== X-Forwarded-Encrypted: i=1; AJvYcCU6yYZGiu4+OL9OVGK1hDDHl0+nnB/aib4lng+fPonyuh5Uhp8d7FIKCRKhx1BNI+Nvjm3OQ3+JxMMdHP0=@vger.kernel.org X-Gm-Message-State: AOJu0Yynhk/hsUtfv+v8Ep2y8EP5KMdUHvbvjkYeOYJhOcCCoo8qk5eG Lr2wKFNmnHQJy3aBtKlqxPvQl1Z8YQTQPhn1+/ztSCXpOdiVS20oOZ4pib++opdtN2Q0KhH465T rIZNZ29fDny1S2qM+S8rgV6OpgJN1kkjs7IYTmcqk/F1FhI514iPWSDlBHGQ= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:220b:b0:678:a4f1:c369 with SMTP id 006d021491bc7-679aeed1436mr3277741eaf.24.1771585881533; Fri, 20 Feb 2026 03:11:21 -0800 (PST) Date: Fri, 20 Feb 2026 03:11:21 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69984159.050a0220.21cd75.01bb.GAE@google.com> Subject: [syzbot] [kernel?] INFO: task hung in restrict_one_thread_callback From: syzbot To: anna-maria@linutronix.de, frederic@kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com, tglx@kernel.org Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 635c467cc14e Add linux-next specific files for 20260213 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=1452f6e6580000 kernel config: https://syzkaller.appspot.com/x/.config?x=61690c38d1398936 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 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=16e41c02580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15813652580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/78b3d15ca8e6/disk-635c467c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a95f3d108ef4/vmlinux-635c467c.xz kernel image: https://storage.googleapis.com/syzbot-assets/e58086838b24/bzImage-635c467c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+7ea2f5e9dfd468201817@syzkaller.appspotmail.com INFO: task syz.0.2812:14643 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2812 state:D stack:25600 pid:14643 tgid:14643 ppid:13375 task_flags:0x400040 flags:0x00080002 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 restrict_one_thread security/landlock/tsync.c:128 [inline] restrict_one_thread_callback+0x320/0x570 security/landlock/tsync.c:162 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2807 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d7f19bf79 RSP: 002b:00007ffe0b192a38 EFLAGS: 00000246 ORIG_RAX: 00000000000000db RAX: fffffffffffffdfc RBX: 00000000000389f1 RCX: 00007f8d7f19bf79 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8d7f41618c RBP: 0000000000000032 R08: 3fffffffffffffff R09: 0000000000000000 R10: 00007ffe0b192b40 R11: 0000000000000246 R12: 00007ffe0b192b60 R13: 00007f8d7f41618c R14: 0000000000038a23 R15: 00007ffe0b192b40 INFO: task syz.0.2812:14644 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2812 state:D stack:28216 pid:14644 tgid:14643 ppid:13375 task_flags:0x400040 flags:0x00080002 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 restrict_one_thread security/landlock/tsync.c:128 [inline] restrict_one_thread_callback+0x320/0x570 security/landlock/tsync.c:162 task_work_run+0x1d9/0x270 kernel/task_work.c:233 get_signal+0x11eb/0x1330 kernel/signal.c:2807 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8d7f19bf79 RSP: 002b:00007f8d8007c0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f8d7f415fa8 RCX: 00007f8d7f19bf79 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f8d7f415fa8 RBP: 00007f8d7f415fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d7f416038 R14: 00007ffe0b1927f0 R15: 00007ffe0b1928d8 INFO: task syz.0.2812:14645 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2812 state:D stack:28648 pid:14645 tgid:14643 ppid:13375 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+0xe9c/0x11f0 security/landlock/tsync.c:539 __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: 0033:0x7f8d7f19bf79 RSP: 002b:00007f8d8005b028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f8d7f416090 RCX: 00007f8d7f19bf79 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000003 RBP: 00007f8d7f2327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d7f416128 R14: 00007f8d7f416090 R15: 00007ffe0b1928d8 INFO: task syz.0.2812:14646 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.2812 state:D stack:28832 pid:14646 tgid:14643 ppid:13375 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+0xe9c/0x11f0 security/landlock/tsync.c:539 __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: 0033:0x7f8d7f19bf79 RSP: 002b:00007f8d8003a028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f8d7f416180 RCX: 00007f8d7f19bf79 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000003 RBP: 00007f8d7f2327e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f8d7f416218 R14: 00007f8d7f416180 R15: 00007ffe0b1928d8 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 2 locks held by getty/5581: #0: ffff8880328890a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&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: 86 Comm: kworker/u8:5 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events_unbound nsim_dev_trap_report_work RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline] RIP: 0010:lock_acquire+0xab/0x2e0 kernel/locking/lockdep.c:5864 Code: 84 c1 00 00 00 65 8b 05 73 b8 9f 11 85 c0 0f 85 b2 00 00 00 65 48 8b 05 bb 72 9f 11 83 b8 14 0b 00 00 00 0f 85 9d 00 00 00 9c <5b> fa 48 c7 c7 8f a1 02 8e e8 57 40 17 0a 65 ff 05 40 b8 9f 11 45 RSP: 0018:ffffc9000260f498 EFLAGS: 00000246 RAX: ffff88801df81e40 RBX: ffffffff818f9166 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8176da62 RDI: 1ffffffff1d2c05c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc9000260f638 R11: ffffffff81b11580 R12: 0000000000000002 R13: ffffffff8e9602e0 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812510b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe09b2c1ff8 CR3: 000000000e74c000 CR4: 00000000003526f0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4501 [inline] slab_alloc_node mm/slub.c:4830 [inline] kmem_cache_alloc_node_noprof+0x384/0x690 mm/slub.c:4882 __alloc_skb+0x1d0/0x7d0 net/core/skbuff.c:702 alloc_skb include/linux/skbuff.h:1383 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:819 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:876 [inline] nsim_dev_trap_report_work+0x29a/0xb80 drivers/net/netdevsim/dev.c:922 process_one_work+0x949/0x1650 kernel/workqueue.c:3279 process_scheduled_works kernel/workqueue.c:3362 [inline] worker_thread+0xb46/0x1140 kernel/workqueue.c:3443 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 --- 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 syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. 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