INFO: task jbd2/sda1-8:2815 blocked 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:25528 pid:2815 tgid:2815 ppid:2 task_flags:0x240040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0xeb1/0x4220 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7008 io_schedule+0x8a/0xf0 kernel/sched/core.c:7835 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:124 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+0x49a6/0x6900 fs/jbd2/commit.c:881 kjournald2+0x200/0x760 fs/jbd2/journal.c:201 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 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/0:0/9: 6 locks held by kdevtmpfs/25: 6 locks held by kworker/1:1/28: 1 lock held by khungtaskd/30: #0: ffffffff896de6e0 ( rcu_read_lock ){....}-{1:3} , at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] , at: rcu_read_lock include/linux/rcupdate.h:850 [inline] , at: debug_show_all_locks+0x3d/0x184 kernel/locking/lockdep.c:6775 3 locks held by kworker/0:2/747: 2 locks held by klogd/2842: 1 lock held by udevd/2853: #0: ffff888101290188 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_dop_revalidate+0xa5/0x740 fs/kernfs/dir.c:1185 3 locks held by crond/2911: 2 locks held by getty/2916: #0: ffff888115c430a0 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x24/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900000432f0 ( &ldata->atomic_read_lock ){+.+.}-{4:4} , at: n_tty_read+0x419/0x1500 drivers/tty/n_tty.c:2211 3 locks held by syz-executor/2953: 1 lock held by syz-executor/2962: #0: ffffffff896ea2f8 ( rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x19e/0x3c0 kernel/rcu/tree_exp.h:343 1 lock held by syz-executor/2963: 1 lock held by syz-executor/2971: #0: ffffffff896ea2f8 (rcu_state.exp_mutex ){+.+.}-{4:4} , at: exp_funnel_lock+0x27f/0x3c0 kernel/rcu/tree_exp.h:311 4 locks held by udevd/5208: #0: ffff88813b70f668 ( &p->lock ){+.+.}-{4:4} , at: seq_read_iter+0xe1/0x1270 fs/seq_file.c:183 #1: ffff88811e1ae888 ( &of->mutex ){+.+.}-{4:4} , at: kernfs_seq_start+0x4f/0x2a0 fs/kernfs/file.c:172 #2: ffff888119150c38 ( kn->active #25 ){++++}-{0:0} , at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] , at: kernfs_seq_start+0xbc/0x2a0 fs/kernfs/file.c:173 #3: ffff88811ab09198 ( &dev->mutex ){....}-{4:4}, at: device_lock_interruptible include/linux/device.h:900 [inline] ){....}-{4:4}, at: manufacturer_show+0x26/0xa0 drivers/usb/core/sysfs.c:142 2 locks held by kworker/1:2/5213: 2 locks held by kworker/1:3/5217: 7 locks held by kworker/1:4/5222: #0: ffff888103ae0148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc9000326fd18 ((work_completion)(&hub->events)){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810b37a198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline] #2: ffff88810b37a198 (&dev->mutex){....}-{4:4}, at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 #3: ffff88811ab09198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008 #4: ffff88811b0ec160 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: __device_attach+0x7e/0x4d0 drivers/base/dd.c:1008 #5: ffffffff8a4f8208 ( input_mutex ){+.+.}-{4:4} , at: class_mutex_intr_constructor include/linux/mutex.h:255 [inline] , at: input_register_device.cold+0x5b/0x375 drivers/input/input.c:2374 #6: ffff888101290188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_add_one+0x38/0x850 fs/kernfs/dir.c:796 3 locks held by kworker/1:6/5353: #0: ffff888103ae0148 ( (wq_completion)usb_hub_wq ){+.+.}-{0:0} , at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc900036cfd18 ( (work_completion)(&hub->events) ){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff88810b332198 ( &dev->mutex ){....}-{4:4} , at: device_lock include/linux/device.h:895 [inline] , at: hub_event+0x1bd/0x4af0 drivers/usb/core/hub.c:5899 4 locks held by kworker/0:6/5612: #0: ffff88810006b148 ( (wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1310/0x19a0 kernel/workqueue.c:3251 #1: ffffc90005c37d18 ( kernfs_notify_work ){+.+.}-{0:0} , at: process_one_work+0x988/0x19a0 kernel/workqueue.c:3252 #2: ffff8881012902b8 ( &root->kernfs_supers_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xf7/0x5f0 fs/kernfs/file.c:932 #3: ffff888101290188 ( &root->kernfs_rwsem ){++++}-{4:4} , at: kernfs_notify_workfn+0xff/0x5f0 fs/kernfs/file.c:933 ============================================= 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 02/12/2026 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:161 [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:346 [inline] watchdog+0xd25/0x1050 kernel/hung_task.c:515 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x6c3/0xcb0 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_ctl_callback - urb status -71 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2971 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:io_serial_out+0x8f/0xb0 drivers/tty/serial/8250/8250_port.c:407 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 61 b5 f5 fe eb a0 e8 ea b5 f5 RSP: 0018:ffffc900001a8440 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: ffffffff832001f5 RDI: ffffffff9418b700 RBP: ffffffff9418b6c0 R08: 0000000000000001 R09: 000000000000001f R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff9418b710 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8882687f6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f60d997666e CR3: 0000000121e9c000 CR4: 00000000003506f0 Call Trace: serial_out drivers/tty/serial/8250/8250.h:133 [inline] serial8250_clear_IER+0xa7/0xd0 drivers/tty/serial/8250/8250_port.c:714 serial8250_console_write+0x252/0x1900 drivers/tty/serial/8250/8250_port.c:3307 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:4913 dev_printk_emit+0xd2/0x10d drivers/base/core.c:4924 __dev_printk+0xcb/0x100 drivers/base/core.c:4936 _dev_err+0xef/0x127 drivers/base/core.c:4979 urb_ctl_callback.cold+0x41/0x8c drivers/input/misc/yealink.c:456 __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+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x50e/0xa70 kernel/time/hrtimer.c:1849 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1866 handle_softirqs+0x1de/0x9d0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xed/0x150 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:194 Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 96 d0 26 fa 48 89 df e8 7e 20 27 fa f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 01 00 00 00 e8 e5 96 1a fa 65 8b 05 5e af 8a 05 85 c0 74 16 5b RSP: 0018:ffffc900014b7538 EFLAGS: 00000246 RAX: 0000000000000006 RBX: ffffffff94156ac0 RCX: 0000000000000040 RDX: 0000000000000000 RSI: ffffffff89010aa0 RDI: ffffffff87afc6a0 RBP: 0000000000000206 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: ffff888114f382e0 R14: dffffc0000000000 R15: 1ffff92000296eae debug_object_activate+0x331/0x490 lib/debugobjects.c:853 debug_rcu_head_queue kernel/rcu/rcu.h:236 [inline] __call_rcu_common.constprop.0+0x35/0x9b0 kernel/rcu/tree.c:3116 security_inode_free+0x53/0x90 security/security.c:1227 __destroy_inode+0x20a/0x740 fs/inode.c:372 destroy_inode+0x91/0x1c0 fs/inode.c:395 evict+0x599/0xad0 fs/inode.c:870 iput_final fs/inode.c:1966 [inline] iput fs/inode.c:2015 [inline] iput+0x79d/0xce0 fs/inode.c:1978 dentry_unlink_inode+0x2a1/0x490 fs/dcache.c:467 __dentry_kill+0x1d0/0x600 fs/dcache.c:670 shrink_kill fs/dcache.c:1147 [inline] shrink_dentry_list+0x180/0x5e0 fs/dcache.c:1174 shrink_dcache_tree+0x100/0x570 fs/dcache.c:1620 do_one_tree fs/dcache.c:1654 [inline] shrink_dcache_for_umount+0xa7/0x400 fs/dcache.c:1671 generic_shutdown_super+0x7e/0x360 fs/super.c:624 kill_anon_super+0x3a/0x60 fs/super.c:1292 deactivate_locked_super+0xc1/0x1b0 fs/super.c:476 deactivate_super fs/super.c:509 [inline] deactivate_super+0xe7/0x110 fs/super.c:505 cleanup_mnt+0x21f/0x450 fs/namespace.c:1312 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x8b8/0x2b60 kernel/exit.c:976 do_group_exit+0xd5/0x2a0 kernel/exit.c:1118 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x7e/0x430 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+0x671/0x7b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7fe4abbb3c Code: Unable to access opcode bytes at 0x7f7fe4abbb12. RSP: 002b:00007ffe01897b80 EFLAGS: 00000206 ORIG_RAX: 0000000000000101 RAX: fffffffffffffffe RBX: 0000000000000175 RCX: 00007f7fe4abbb3c RDX: 0000000000090800 RSI: 00007f7fe4b525d3 RDI: 00000000ffffff9c RBP: 00007ffe01897c2c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 000000000000008d R13: 0000000000000000 R14: 0000000000064d84 R15: 00007ffe01897c80