INFO: task jbd2/sda1-8:2817 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:26232 pid:2817 tgid:2817 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x1325/0x47d0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7322 io_schedule+0x8a/0xf0 kernel/sched/core.c:8150 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 INFO: lockdep is turned off. 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_irq_callback - urb status -71 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5226 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(lazy) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 Workqueue: events_power_efficient gc_worker 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 56 47 52 04 e8 01 28 f1 fe eb a0 e8 8a 28 f1 RSP: 0000:ffffc900001a84a8 EFLAGS: 00000002 RAX: 000000000000005b RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff832b3015 RDI: ffffffff9423dda0 RBP: ffffffff9423dd60 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 205d303354202020 R12: 0000000000000000 R13: 000000000000005b R14: ffffffff9407e8a0 R15: ffffffff832b2fb0 FS: 0000000000000000(0000) GS:ffff888268742000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e51cff8 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:3239 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3301 [inline] serial8250_console_write+0xe2c/0x1a50 drivers/tty/serial/8250/8250_port.c:3379 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_irq_callback.cold+0x41/0xfd drivers/input/misc/yealink.c:418 __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:__seqprop_spinlock_sequence include/linux/seqlock.h:228 [inline] RIP: 0010:nf_conntrack_get_ht include/net/netfilter/nf_conntrack.h:343 [inline] RIP: 0010:gc_worker+0x2bb/0x1660 net/netfilter/nf_conntrack_core.c:1509 Code: 00 00 48 c7 c7 a8 a4 f3 8a e8 91 cb 07 fb 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 af 9b 2b fb 58 48 85 db 0f 85 d0 0f 00 00 00 a1 2b fb 8b 1d da 4c 6b 04 89 dd 31 ff 83 e5 01 89 ee e8 5c RSP: 0000:ffffc90001fafb58 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff86886256 RDX: ffff888114cf3c00 RSI: ffffffff86886265 RDI: ffff888114cf3c00 RBP: 000000000001ac93 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 1ffffffff12ddc79 R12: dffffc0000000000 R13: 0000000000040000 R14: 000000000000d64a R15: 0000000000001770 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