INFO: task kworker/u8:3:58 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:3 state:D stack:19816 pid:58 tgid:58 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7307 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline] __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline] rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244 f2fs_down_write fs/f2fs/f2fs.h:2294 [inline] f2fs_balance_fs+0x5af/0x7f0 fs/f2fs/segment.c:464 f2fs_write_inode+0x3fb/0x5f0 fs/f2fs/inode.c:820 write_inode fs/fs-writeback.c:1564 [inline] __writeback_single_inode+0x6f4/0x1000 fs/fs-writeback.c:1784 writeback_sb_inodes+0x6b7/0xf60 fs/fs-writeback.c:2015 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2086 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2197 wb_check_old_data_flush fs/fs-writeback.c:2301 [inline] wb_do_writeback fs/fs-writeback.c:2354 [inline] wb_workfn+0xaf4/0xf00 fs/fs-writeback.c:2382 process_one_work kernel/workqueue.c:3263 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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/u8:0/12: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000117ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000117ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88805b8508b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff88805b8508b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 4 locks held by kworker/u8:1/13: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000127ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000127ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff888049f908b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff888049f908b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 4 locks held by kworker/u8:2/37: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90000ac7ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90000ac7ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880695c08b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff8880695c08b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 1 lock held by khungtaskd/39: #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:3/58: #0: ffff88801eac1938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801eac1938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000124fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000124fba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88803406c0d0 (&type->s_umount_key#63){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562 #3: ffff8880572219f8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_down_write fs/f2fs/f2fs.h:2294 [inline] #3: ffff8880572219f8 (&sbi->gc_lock){+.+.}-{4:4}, at: f2fs_balance_fs+0x5af/0x7f0 fs/f2fs/segment.c:464 4 locks held by kworker/u8:8/1178: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc90004f77ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc90004f77ba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880696608b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff8880696608b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 4 locks held by kworker/u8:10/3475: 4 locks held by kworker/u8:11/3484: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000d3afba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000d3afba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88805ba308b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff88805ba308b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 4 locks held by kworker/u8:13/3625: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000d98fba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000d98fba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880695808b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff8880695808b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 2 locks held by udevd/5170: 2 locks held by getty/5556: #0: ffff88823bf6a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1400 drivers/tty/n_tty.c:2222 2 locks held by udevd/5917: #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8d5aa800 (rcu_read_lock){....}-{1:3}, at: __d_lookup+0x66/0x780 fs/dcache.c:2390 #1: ffff88802f93eed0 (&lockref->lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #1: ffff88802f93eed0 (&lockref->lock){+.+.}-{3:3}, at: __d_lookup+0x23e/0x780 fs/dcache.c:2397 5 locks held by syz.0.145/6910: 4 locks held by kworker/u8:4/8532: #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88813ff69138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000d2cfba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000d2cfba0 ((work_completion)(&rdev->wiphy_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff88805bfa08b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: class_wiphy_constructor include/net/cfg80211.h:6358 [inline] #2: ffff88805bfa08b8 (&rdev->wiphy.mtx){+.+.}-{4:4}, at: cfg80211_wiphy_work+0xc4/0x470 net/wireless/core.c:421 #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #3: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 2 locks held by syz.9.421/8892: 3 locks held by syz.3.422/8897: 2 locks held by syz.8.424/8907: 3 locks held by syz.5.423/8908: #0: ffff88804c2200d0 (&type->s_umount_key#104/1){+.+.}-{4:4}, at: alloc_super+0x1ba/0x9a0 fs/super.c:344 #1: ffff8880231a8978 (&sbi->vh_mutex){+.+.}-{4:4}, at: hfsplus_fill_super+0x1296/0x1b70 fs/hfsplus/super.c:573 #2: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:44 [inline] #2: ffff8880b893faa8 (&s->lock_key#8){+.+.}-{3:3}, at: ___slab_alloc+0x2ad/0x13f0 mm/slub.c:4571 4 locks held by dhcpcd-run-hook/8909: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 39 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 nmi_cpu_backtrace+0x39e/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline] watchdog+0xf60/0xfa0 kernel/hung_task.c:495 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 17 Comm: pr/legacy Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:rdtsc_ordered arch/x86/include/asm/tsc.h:57 [inline] RIP: 0010:delay_tsc+0x71/0xc0 arch/x86/lib/delay.c:72 Code: 00 00 e8 c2 a2 d0 f6 65 8b 05 5b 59 e3 06 85 c0 74 1c f3 90 bf 01 00 00 00 e8 fb a0 d0 f6 e8 26 64 01 00 39 c5 75 0e 0f 01 f9 <66> 90 eb bd e8 26 c1 73 f6 eb dd 4c 29 fb e8 0c 64 01 00 89 c5 0f RSP: 0018:ffffc90000167870 EFLAGS: 00000246 RAX: 0000000091574f6d RBX: 0000000000000899 RCX: 0000000000000000 RDX: 00000000000000c1 RSI: ffffffff8b3ddd40 RDI: ffffffff8b3ddd00 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff8abf1680 R12: 1ffffffff31d1e1e R13: 00000000ffffffff R14: 000000c191574927 R15: 0000000000000577 FS: 0000000000000000(0000) GS:ffff888126df9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b9da02368 CR3: 0000000069d5a000 CR4: 00000000003526f0 Call Trace: udelay include/asm-generic/delay.h:62 [inline] wait_for_lsr+0x166/0x2f0 drivers/tty/serial/8250/8250_port.c:1967 fifo_wait_for_lsr drivers/tty/serial/8250/8250_port.c:3234 [inline] serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3257 [inline] serial8250_console_write+0x11bd/0x1b40 drivers/tty/serial/8250/8250_port.c:3342 console_emit_next_record kernel/printk/printk.c:3091 [inline] console_flush_all+0x666/0xb40 kernel/printk/printk.c:3199 __console_flush_and_unlock+0x9b/0x160 kernel/printk/printk.c:3258 legacy_kthread_func+0x13b/0x1a0 kernel/printk/printk.c:3611 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245