INFO: task jbd2/sda1-8:2816 blocked in I/O wait for more than 149 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:25848 pid:2816 tgid:2816 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x1325/0x47d0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 io_schedule+0x8a/0xf0 kernel/sched/core.c:8154 bit_wait_io+0xd/0xe0 kernel/sched/wait_bit.c:250 __wait_on_bit+0x65/0x180 kernel/sched/wait_bit.c:52 out_of_line_wait_on_bit+0xdc/0x110 kernel/sched/wait_bit.c:67 wait_on_bit_io include/linux/wait_bit.h:105 [inline] __wait_on_buffer+0x64/0x70 fs/buffer.c:118 wait_on_buffer include/linux/buffer_head.h:422 [inline] journal_wait_on_commit_record fs/jbd2/commit.c:170 [inline] jbd2_journal_commit_transaction+0x4837/0x6700 fs/jbd2/commit.c:907 kjournald2+0x200/0x760 fs/jbd2/journal.c:199 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 4 locks held by kworker/1:0/23: 1 lock held by khungtaskd/30: #0: ffffffff896e2b40 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] , at: rcu_read_lock include/linux/rcupdate.h:840 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 2 locks held by kworker/u8:2/36: #0: ffff8881000ac140 ( (wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90000267d18 ( (work_completion)(&sub_info->work) ){+.+.}-{0:0} , at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by getty/2917: #0: ffff8881093920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000452e8 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x419/0x14e0 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:2/5198: #0: ffff88810006b140 ((wq_completion)events){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9000203fd18 ( free_ipc_work ){+.+.}-{0:0} , at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffffffff896ee5e8 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 1 lock held by udevd/5240: 3 locks held by kworker/0:4/5256: #0: ffff8881056b2d40 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc900020efd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 #2: ffff888109fc41d8 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:1102 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5902 3 locks held by kworker/0:6/5276: 2 locks held by kworker/1:5/5395: 2 locks held by kworker/u8:0/8532: #0: ffff8881000ac140 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9001407fd18 ((work_completion)(&sub_info->work)){+.+.}-{0:0} , at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by kworker/1:4/9689: 5 locks held by kworker/1:7/9820: 2 locks held by kworker/u8:1/11302: #0: ffff8881000ac140 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc90012e47d18 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by kworker/u8:3/14225: 2 locks held by kworker/1:2/14527: 3 locks held by kworker/1:3/15825: 2 locks held by syz-executor/15980: 1 lock held by syz-executor/15986: 2 locks held by kworker/u8:4/15987: #0: ffff8881000ac140 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x12b1/0x1940 kernel/workqueue.c:3297 #1: ffffc9001696fd18 ((work_completion)(&sub_info->work) ){+.+.}-{0:0} , at: process_one_work+0x988/0x1940 kernel/workqueue.c:3298 2 locks held by kworker/u8:5/15995: 1 lock held by syz-executor/16290: 2 locks held by kworker/u8:6/16304: 2 locks held by kworker/u8:7/16310: 2 locks held by modprobe/16313: 2 locks held by modprobe/16844: 2 locks held by modprobe/16845: 2 locks held by modprobe/16848: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x12d/0x151 lib/nmi_backtrace.c:122 nmi_trigger_cpumask_backtrace+0x21c/0x2a0 lib/nmi_backtrace.c:65 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x141/0x190 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xcb1/0x1030 kernel/hung_task.c:561 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 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: yealink 4-1:36.0: urb_ctl_callback - urb status -71 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 15825 Comm: kworker/1:3 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events drain_vmap_area_work RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:408 Code: 48 8d 7d 40 44 89 e1 48 b8 00 00 00 00 00 fc ff df 48 89 fa d3 e3 48 c1 ea 03 80 3c 02 00 75 1c 66 03 5d 40 44 89 e8 89 da ee <5b> 5d 41 5c 41 5d e9 16 ed 52 04 e8 a1 f6 f0 fe eb a0 e8 2a f7 f0 RSP: 0018:ffffc900001a84b8 EFLAGS: 00000002 RAX: 0000000000000031 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff832b5a15 RDI: ffffffff94245da0 RBP: ffffffff94245d60 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000031 R14: ffffffff940868a2 R15: ffffffff832b59b0 FS: 0000000000000000(0000) GS:ffff88826873a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f65647914e8 CR3: 00000000094ac000 CR4: 00000000003506f0 Call Trace: serial_port_out include/linux/serial_core.h:813 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3245 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3307 [inline] serial8250_console_write+0xe2c/0x1a50 drivers/tty/serial/8250/8250_port.c:3385 console_emit_next_record kernel/printk/printk.c:3183 [inline] console_flush_one_record+0x790/0xe50 kernel/printk/printk.c:3269 console_flush_all kernel/printk/printk.c:3343 [inline] __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3413 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479 dev_vprintk_emit+0x391/0x3e0 drivers/base/core.c:4996 dev_printk_emit+0xd2/0x10d drivers/base/core.c:5007 __dev_printk+0xcb/0x100 drivers/base/core.c:5019 _dev_err+0xef/0x127 drivers/base/core.c:5062 urb_ctl_callback.cold+0x41/0x8c drivers/input/misc/yealink.c:447 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005 __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2113 handle_softirqs+0x1dd/0x990 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:98 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:115 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:140 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline] RIP: 0010:kasan_check_range+0x180/0x1e0 mm/kasan/generic.c:200 Code: ff ff ff 48 85 d2 74 98 48 01 ea eb 1a 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 83 c0 01 48 39 d0 0f 84 79 ff ff ff 80 38 00 <74> ee e9 57 ff ff ff b8 01 00 00 00 c3 cc cc cc cc 48 29 c3 48 89 RSP: 0018:ffffc90016a07898 EFLAGS: 00000246 RAX: ffffed102113de59 RBX: ffffed102113de5a RCX: ffffffff82215626 RDX: ffffed102113de5a RSI: 0000000000000004 RDI: ffff8881089ef2c8 RBP: ffffed102113de59 R08: 0000000000000000 R09: ffffed102113de59 R10: ffff8881089ef2cb R11: 0000000000000000 R12: ffff8881089ef280 R13: 0000000000000001 R14: 000000000014e308 R15: dffffc0000000000 instrument_atomic_read include/linux/instrumented.h:82 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] __page_table_check_zero+0x166/0x410 mm/page_table_check.c:142 page_table_check_free include/linux/page_table_check.h:46 [inline] __free_pages_prepare mm/page_alloc.c:1407 [inline] __free_frozen_pages+0x725/0xf50 mm/page_alloc.c:2950 kasan_depopulate_vmalloc_pte+0x5d/0x80 mm/kasan/shadow.c:484 apply_to_pte_range mm/memory.c:3338 [inline] apply_to_pmd_range mm/memory.c:3382 [inline] apply_to_pud_range mm/memory.c:3418 [inline] apply_to_p4d_range mm/memory.c:3454 [inline] __apply_to_page_range+0xb1d/0x1520 mm/memory.c:3490 __kasan_release_vmalloc+0xd7/0xe0 mm/kasan/shadow.c:602 kasan_release_vmalloc include/linux/kasan.h:593 [inline] kasan_release_vmalloc_node mm/vmalloc.c:2284 [inline] purge_vmap_node+0x210/0xb40 mm/vmalloc.c:2306 __purge_vmap_area_lazy+0x90a/0xc00 mm/vmalloc.c:2396 drain_vmap_area_work+0x27/0x40 mm/vmalloc.c:2430 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322 process_scheduled_works kernel/workqueue.c:3405 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245