INFO: task syz.5.1811:13245 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1811 state:D stack:24384 pid:13245 tgid:13245 ppid:7052 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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: 0033:0x7f164979c799 RSP: 002b:00007f1649b3fba8 EFLAGS: 00000246 ORIG_RAX: 00000000000000db RAX: fffffffffffffdfc RBX: 000000000008a597 RCX: 00007f164979c799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1649a1609c RBP: 0000000000000032 R08: 3fffffffffffffff R09: 0000000000000000 R10: 00007f1649b3fcb0 R11: 0000000000000246 R12: 00007f1649b3fcd0 R13: 00007f1649a1609c R14: 000000000008a5c9 R15: 00007f1649b3fcb0 INFO: task syz.5.1811:13246 blocked for more than 144 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1811 state:D stack:28160 pid:13246 tgid:13245 ppid:7052 task_flags:0x400140 flags:0x00080006 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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: 0033:0x7f164979c799 RSP: 002b:00007f164a61f028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f1649a15fa0 RCX: 00007f164979c799 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 0000000000000009 RBP: 00007f1649832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1649a16038 R14: 00007f1649a15fa0 R15: 00007f1649b3fa48 INFO: task syz.5.1811:13247 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1811 state:D stack:28648 pid:13247 tgid:13245 ppid:7052 task_flags:0x400140 flags:0x00080006 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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: 0033:0x7f164979c799 RSP: 002b:00007f164a5fe028 EFLAGS: 00000246 ORIG_RAX: 00000000000001be RAX: ffffffffffffffda RBX: 00007f1649a16090 RCX: 00007f164979c799 RDX: 0000000000000000 RSI: 000000000000000a RDI: 0000000000000008 RBP: 00007f1649832c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1649a16128 R14: 00007f1649a16090 R15: 00007f1649b3fa48 INFO: task syz.5.1811:13248 blocked for more than 145 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.1811 state:D stack:28712 pid:13248 tgid:13245 ppid:7052 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 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: 0033:0x7f164979c799 RSP: 002b:00007f164a5dd0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f1649a16188 RCX: 00007f164979c799 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f1649a16188 RBP: 00007f1649a16180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1649a16218 R14: 00007f1649b3f960 R15: 00007f1649b3fa48 Showing all locks held in the system: 1 lock held by khungtaskd/30: #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75e520 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 6 locks held by kworker/0:2/1689: #0: ffff888020285948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline] #0: ffff888020285948 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359 #1: ffffc90005aefc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline] #1: ffffc90005aefc40 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359 #2: ffff888029bdc198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff888029bdc198 (&dev->mutex){....}-{4:4}, at: hub_event+0x17f/0x4f30 drivers/usb/core/hub.c:5899 #3: ffff888055dac198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #3: ffff888055dac198 (&dev->mutex){....}-{4:4}, at: usb_disconnect+0xf8/0x990 drivers/usb/core/hub.c:2336 #4: ffff888056e25160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #4: ffff888056e25160 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1106 [inline] #4: ffff888056e25160 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x860 drivers/base/dd.c:1304 #5: ffff888024d2c188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_disconnect+0x6d/0x500 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2708 2 locks held by pvrusb2-context/2347: #0: ffff888024d2c188 (&hdw->big_lock_mutex){+.+.}-{4:4}, at: pvr2_hdw_initialize+0xe4/0x3c50 drivers/media/usb/pvrusb2/pvrusb2-hdw.c:2326 #1: ffffffff8e5fb8f0 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xfc/0x2c0 kernel/umh.c:214 2 locks held by getty/5582: #0: ffff888035dfb0a0 (&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 5 locks held by kworker/u8:21/6347: 4 locks held by udevd/6441: #0: ffff88802a9042f0 (&p->lock){+.+.}-{4:4}, at: seq_read_iter+0xb7/0xe10 fs/seq_file.c:183 #1: ffff88806a485088 (&of->mutex#2){+.+.}-{4:4}, at: kernfs_seq_start+0x5c/0x420 fs/kernfs/file.c:172 #2: ffff888032b4fa58 (kn->active#26){++++}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff888032b4fa58 (kn->active#26){++++}-{0:0}, at: kernfs_seq_start+0xb2/0x420 fs/kernfs/file.c:173 #3: ffff888055dac198 (&dev->mutex){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] #3: ffff888055dac198 (&dev->mutex){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 1 lock held by syz.4.2380/15419: #0: ffff888029bdc198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #0: ffff888029bdc198 (&dev->mutex){....}-{4:4}, at: usbdev_open+0x182/0x770 drivers/usb/core/devio.c:1054 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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:436 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 9e 6c 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 f2 1a 00 fb f4 fc e9 02 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000246 RAX: 0000000000e0992b RBX: ffffffff819a900a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8def7968 RDI: ffffffff8c27c200 RBP: ffffffff8e407eb0 R08: ffff8880b863395b R09: 1ffff110170c672b R10: dffffc0000000000 R11: ffffed10170c672c R12: 0000000000000000 R13: 1ffffffff1c929d8 R14: 0000000000000000 R15: 1ffffffff1c929d8 FS: 0000000000000000(0000) GS:ffff88812545d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2dcede92f8 CR3: 00000000763a4000 CR4: 00000000003526f0 DR0: 0000000080000000 DR1: 0000000000000001 DR2: fffffffffffffffe DR3: 0000000000000006 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:760 start_kernel+0x385/0x3d0 init/main.c:1210 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147