INFO: task jbd2/sda1-8:2817 blocked in I/O wait for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:jbd2/sda1-8 state:D stack:26952 pid:2817 tgid:2817 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0xf89/0x4840 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7282 io_schedule+0x8a/0xf0 kernel/sched/core.c:8109 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:123 wait_on_buffer include/linux/buffer_head.h:420 [inline] journal_wait_on_commit_record fs/jbd2/commit.c:171 [inline] jbd2_journal_commit_transaction+0x494c/0x6870 fs/jbd2/commit.c:910 kjournald2+0x200/0x760 fs/jbd2/journal.c:201 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: 2 locks held by kworker/0:0/9: 5 locks held by kworker/u8:0/12: 3 locks held by kworker/1:0/23: 4 locks held by kworker/1:1/28: 1 lock held by khungtaskd/30: #0: ffffffff896ddaa0 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] , at: rcu_read_lock include/linux/rcupdate.h:838 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:1/32: #0: ffff888113345940 ( (wq_completion)ipv6_addrconf ){+.+.}-{0:0} , at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc90000227d18 ( (work_completion)(&(&net->ipv6.addr_chk_work)->work) ){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffffffff8aaf92a0 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] (rtnl_mutex){+.+.}-{4:4}, at: addrconf_verify_work+0x12/0x30 net/ipv6/addrconf.c:4746 3 locks held by kworker/1:2/2513: 6 locks held by kworker/1:3/2815: 2 locks held by udevd/2857: 2 locks held by getty/2919: #0: ffff8881087f00a0 (&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+0x419/0x14f0 drivers/tty/n_tty.c:2211 8 locks held by kworker/0:5/5231: #0: ffff888105ef4d40 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x12d6/0x1980 kernel/workqueue.c:3277 #1: ffffc9000227fd18 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x973/0x1980 kernel/workqueue.c:3278 #2: ffff88810d7041d8 (&dev->mutex){....}-{4:4} , at: device_lock include/linux/device.h:1040 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88813cd811d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] #3: ffff88813cd811d8 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #4: ffff88810fbdf1a0 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] ffff88810fbdf1a0 (&dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #5: ffff8881251a5a58 ( &dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1040 [inline] &dev->mutex){....}-{4:4}, at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1076 #6: ffffffff8a8a8468 ( minors_rwsem){+.+.}-{4:4} , at: hidraw_connect+0x75/0x440 drivers/hid/hidraw.c:612 #7: ffff888100e87980 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:826 5 locks held by kworker/1:6/5442: 1 lock held by syz.4.94/5521: 2 locks held by syz-executor/5528: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5531: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5533: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5536: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5545: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5575: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: ops_exit_rtnl_list net/core/net_namespace.c:173 [inline] , at: ops_undo_list+0x7ec/0xab0 net/core/net_namespace.c:248 2 locks held by syz-executor/5586: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2102 2 locks held by syz-executor/5588: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2102 2 locks held by syz-executor/5596: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2102 2 locks held by syz-executor/5602: #0: ffffffff8aae0868 ( pernet_ops_rwsem ){++++}-{4:4} , at: copy_net_ns+0x41e/0x780 net/core/net_namespace.c:575 #1: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: register_netdevice_notifier_net+0x23/0xb0 net/core/dev.c:2102 1 lock held by syz-executor/5625: #0: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/5630: #0: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/5633: #0: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/5638: #0: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 1 lock held by syz-executor/5641: #0: ffffffff8aaf92a0 ( rtnl_mutex ){+.+.}-{4:4} , at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] , at: inet_rtm_newaddr+0x30c/0x18b0 net/ipv4/devinet.c:978 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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:113 nmi_trigger_cpumask_backtrace+0x1d7/0x230 lib/nmi_backtrace.c:62 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 2-1:36.0: urb_irq_callback - urb status -71 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5442 Comm: kworker/1:6 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 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 c3 cc cc cc cc e8 d1 ce f4 fe eb a0 e8 5a cf f4 RSP: 0018:ffffc900001a8490 EFLAGS: 00000002 RAX: 0000000000000031 RBX: 00000000000003f8 RCX: 0000000000000000 RDX: 00000000000003f8 RSI: ffffffff83232705 RDI: ffffffff941d8d40 RBP: ffffffff941d8d00 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000031 R14: 0000000000000010 R15: ffffffff832326a0 FS: 0000000000000000(0000) GS:ffff8882687a9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4d7b534fd8 CR3: 00000000094ac000 CR4: 00000000003506f0 Call Trace: serial_port_out include/linux/serial_core.h:811 [inline] serial8250_console_putchar drivers/tty/serial/8250/8250_port.c:3217 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3279 [inline] serial8250_console_write+0xde8/0x1900 drivers/tty/serial/8250/8250_port.c:3357 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+0x394/0x3e0 drivers/base/core.c:4930 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4941 __dev_printk+0xcb/0x100 drivers/base/core.c:4953 _dev_err+0xef/0x127 drivers/base/core.c:4996 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:1930 [inline] __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2011 handle_softirqs+0x1dd/0x9e0 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:1061 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 fb 6b 68 0b 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 86 95 61 09 0f 82 a4 02 00 00 8b 35 0e a5 61 09 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d 6b 68 0b 0f 85 ed 02 00 00 48 83 c4 RSP: 0018:ffffc9000221fad8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: ffffffff890a43d9 RDI: ffffffff87b04160 RBP: ffffffff896ddaa0 R08: 000000008ff434a7 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] gc_worker+0x222/0x1630 net/netfilter/nf_conntrack_core.c:1543 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 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 ---------------- Code disassembly (best guess): 0: 48 8d 7d 40 lea 0x40(%rbp),%rdi 4: 44 89 e1 mov %r12d,%ecx 7: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax e: fc ff df 11: 48 89 fa mov %rdi,%rdx 14: d3 e3 shl %cl,%ebx 16: 48 c1 ea 03 shr $0x3,%rdx 1a: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) 1e: 75 1c jne 0x3c 20: 66 03 5d 40 add 0x40(%rbp),%bx 24: 44 89 e8 mov %r13d,%eax 27: 89 da mov %ebx,%edx 29: ee out %al,(%dx) * 2a: 5b pop %rbx <-- trapping instruction 2b: 5d pop %rbp 2c: 41 5c pop %r12 2e: 41 5d pop %r13 30: c3 ret 31: cc int3 32: cc int3 33: cc int3 34: cc int3 35: e8 d1 ce f4 fe call 0xfef4cf0b 3a: eb a0 jmp 0xffffffdc 3c: e8 .byte 0xe8 3d: 5a pop %rdx 3e: cf iret 3f: f4 hlt