INFO: task syz.0.17:6022 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:25448 pid:6022 ppid:5915 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1266 [inline] io_wq_put_and_exit+0x474/0x810 io_uring/io-wq.c:1294 io_uring_clean_tctx+0x130/0x1b0 io_uring/tctx.c:204 io_uring_cancel_generic+0x610/0x6c0 io_uring/io_uring.c:3507 io_uring_files_cancel include/linux/io_uring.h:69 [inline] do_exit+0x5f1/0x2460 kernel/exit.c:829 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f1aa179aeb9 RSP: 002b:00007ffed1be8ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f1aa179aeb9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f1aa19de280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1aa19de280 R14: 0000000000000003 R15: 00007ffed1be90b0 INFO: task syz.1.18:6030 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.1.18 state:D stack:25448 pid:6030 ppid:5914 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0xc1/0x2d0 kernel/time/timer.c:2144 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x2cb/0x5b0 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1266 [inline] io_wq_put_and_exit+0x474/0x810 io_uring/io-wq.c:1294 io_uring_clean_tctx+0x130/0x1b0 io_uring/tctx.c:204 io_uring_cancel_generic+0x610/0x6c0 io_uring/io_uring.c:3507 io_uring_files_cancel include/linux/io_uring.h:69 [inline] do_exit+0x5f1/0x2460 kernel/exit.c:829 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 __do_sys_exit_group kernel/exit.c:1035 [inline] __se_sys_exit_group kernel/exit.c:1033 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1033 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9de159aeb9 RSP: 002b:00007fff8e8e2cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f9de159aeb9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: 0000000000000000 R09: 00007f9de17de280 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9de17de280 R14: 0000000000000003 R15: 00007fff8e8e2db0 Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 4 locks held by kworker/u4:2/34: 6 locks held by kworker/1:1H/96: 3 locks held by kworker/1:2/968: #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017c70938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #1: ffffc9000434fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc9000434fd00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_scheduled_works+0x96f/0x15d0 kernel/workqueue.c:2711 #2: ffff888054f45240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x286/0x31b0 drivers/net/netdevsim/fib.c:1491 3 locks held by kworker/u4:13/3539: 2 locks held by getty/5530: #0: ffff8880320020a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x433/0x1390 drivers/tty/n_tty.c:2217 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a6/0x3e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf3d/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 96 Comm: kworker/1:1H Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: kblockd blk_mq_timeout_work RIP: 0010:mark_lock+0xe2/0x320 kernel/locking/lockdep.c:4656 Code: 03 42 0f b6 04 28 84 c0 0f 85 06 02 00 00 83 3d e3 83 c3 15 00 74 36 45 31 ff 49 83 c7 60 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 ff e8 44 5b 76 00 b8 01 00 00 00 45 85 27 74 50 48 83 RSP: 0018:ffffc900001f0660 EFLAGS: 00000046 RAX: 1ffffffff21656d8 RBX: ffff88801fae5a00 RCX: ffffffff8168e064 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff911bf508 RBP: 0000000000000008 R08: ffffffff911bf50f R09: 1ffffffff2237ea1 R10: dffffc0000000000 R11: fffffbfff2237ea2 R12: 0000000000000100 R13: dffffc0000000000 R14: ffff88801fae65a8 R15: ffffffff90b2b6c0 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3f94e708c0 CR3: 0000000050804000 CR4: 00000000003506e0 Call Trace: mark_usage kernel/locking/lockdep.c:4599 [inline] __lock_acquire+0xd5c/0x7d40 kernel/locking/lockdep.c:5091 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162 lock_timer_base+0x123/0x270 kernel/time/timer.c:999 __mod_timer+0xf9/0xdb0 kernel/time/timer.c:1080 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:console_flush_all+0x8b1/0xd20 arch/x86/include/asm/irqflags.h:-1 Code: ed 01 00 00 e8 e0 82 1b 00 4d 85 ff 48 8b 5c 24 38 75 07 e8 d1 82 1b 00 eb 06 e8 ca 82 1b 00 fb 49 bf 00 00 00 00 00 fc ff df <48> 8b 44 24 58 42 0f b6 04 38 84 c0 0f 85 2f 02 00 00 80 3b 01 0f RSP: 0018:ffffc900024ef240 EFLAGS: 00000293 RAX: ffffffff816b91e6 RBX: ffffc900024ef3df RCX: ffff88801fae5a00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900024ef3b0 R08: ffffffff911bf507 R09: 1ffffffff2237ea0 R10: dffffc0000000000 R11: fffffbfff2237ea1 R12: ffffffff8d8b7ca0 R13: 1ffffffff19f96f8 R14: ffffffff8d8b7cf8 R15: dffffc0000000000 console_unlock+0xad/0x350 kernel/printk/printk.c:3069 vprintk_emit+0x497/0x610 kernel/printk/printk.c:2341 _printk+0xde/0x130 kernel/printk/printk.c:2366 null_timeout_rq+0x238/0x350 drivers/block/null_blk/main.c:1716 blk_mq_rq_timed_out block/blk-mq.c:1565 [inline] blk_mq_handle_expired+0x170/0x2c0 block/blk-mq.c:1633 bt_iter+0x2ed/0x3b0 block/blk-mq-tag.c:293 __sbitmap_for_each_set include/linux/sbitmap.h:286 [inline] sbitmap_for_each_set+0x308/0x5e0 include/linux/sbitmap.h:307 bt_for_each block/blk-mq-tag.c:325 [inline] blk_mq_queue_tag_busy_iter+0x47b/0x7f0 block/blk-mq-tag.c:534 blk_mq_timeout_work+0x1df/0x3e0 block/blk-mq.c:1675 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293