INFO: task bch-reclaim/loo:17739 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:bch-reclaim/loo state:D stack:18792 pid:17739 tgid:17739 ppid:2 task_flags:0x200040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5360 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7118 __mutex_lock_common kernel/locking/mutex.c:676 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:760 bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:773 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e33cf20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e33cf20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e33cf20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5620: #0: ffff88814dda60a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 4 locks held by kworker/u8:7/5962: 6 locks held by syz-executor/13708: #0: ffff88804f2960e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88804f2960e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88804f2960e0 (&type->s_umount_key#90){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505 #1: ffff888066280278 (&c->state_lock){+.+.}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676 #2: ffff8880662caf68 (&j->reclaim_lock){+.+.}-{4:4}, at: journal_flush_done+0x86/0x810 fs/bcachefs/journal_reclaim.c:884 #3: ffff888066284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888066284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888066284398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7f4/0xd80 fs/bcachefs/btree_iter.c:3505 #4: ffff888066284740 (&wb->flushing.lock){+.+.}-{4:4}, at: btree_write_buffer_flush_seq+0x18bd/0x1a40 fs/bcachefs/btree_write_buffer.c:571 #5: ffff8880662a6710 (&c->gc_lock){.+.+}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211 6 locks held by kworker/0:13/17047: #0: ffff88801defd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801defd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000d027ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000d027ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880282e6198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff8880282e6198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 #4: ffff8880b8624008 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #5: ffffffff92c714a8 (pvclock_gtod_data){-.-.}-{0:0}, at: notifier_call_chain+0x1b3/0x3e0 kernel/notifier.c:85 6 locks held by kworker/0:17/17052: #0: ffff88801defd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline] #0: ffff88801defd148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346 #1: ffffc9000cfa7ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline] #1: ffffc9000cfa7ba0 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346 #2: ffff8880282a1198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #2: ffff8880282a1198 (&dev->mutex){....}-{4:4}, at: hub_event+0x184/0x4a20 drivers/usb/core/hub.c:5898 #3: ffff888022e80198 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #3: ffff888022e80198 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #4: ffff888022e86160 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff888022e86160 (&dev->mutex){....}-{4:4}, at: __device_attach+0x88/0x400 drivers/base/dd.c:1006 #5: ffffffff8e1e3150 (umhelper_sem){++++}-{4:4}, at: usermodehelper_read_trylock+0xf0/0x2b0 kernel/umh.c:214 1 lock held by bch-reclaim/loo/17739: #0: ffff8880662caf68 (&j->reclaim_lock){+.+.}-{4:4}, at: bch2_journal_reclaim_thread+0x16b/0x4f0 fs/bcachefs/journal_reclaim.c:773 1 lock held by syz.2.4342/18831: #0: ffff88804f2960e0 (&type->s_umount_key#90){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88804f2960e0 (&type->s_umount_key#90){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x47c/0x820 arch/x86/kernel/process.c:148 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: 5848 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:update_load_avg+0x1453/0x1880 kernel/sched/fair.c:4759 Code: 00 4c 8b 7c 24 08 4c 8b 6c 24 10 74 08 4c 89 ff e8 b2 7e 8e 00 4d 89 37 80 3c 2b 00 74 08 4c 89 e7 e8 a1 7e 8e 00 4d 89 2c 24 <48> 83 c4 58 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 49 8d RSP: 0018:ffffc900040bf830 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000154 RDX: 000000000000022c RSI: ffff8880566f9c00 RDI: ffff8880b863a058 RBP: dffffc0000000000 R08: ffff888030e99e47 R09: 1ffff110061d33c8 R10: dffffc0000000000 R11: ffffed10061d33c9 R12: 0000000000000001 R13: ffff8880b863a040 R14: ffff8880566f9cc0 R15: ffff888021f38150 FS: 000055556c3cb500(0000) GS:ffff8881259f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f05bffc7f70 CR3: 0000000074e62000 CR4: 00000000003526f0 Call Trace: set_next_entity+0x110/0x690 kernel/sched/fair.c:5477 pick_next_task_fair+0x94d/0xba0 kernel/sched/fair.c:8893 __pick_next_task+0xe4/0x450 kernel/sched/core.c:6004 pick_next_task kernel/sched/core.c:6089 [inline] __schedule+0x7a4/0x4cc0 kernel/sched/core.c:6905 __schedule_loop kernel/sched/core.c:7046 [inline] schedule+0x165/0x360 kernel/sched/core.c:7061 do_nanosleep+0x1c7/0x600 kernel/time/hrtimer.c:2100 hrtimer_nanosleep+0x169/0x360 kernel/time/hrtimer.c:2147 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1399 [inline] __se_sys_clock_nanosleep+0x2f1/0x380 kernel/time/posix-timers.c:1376 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd26b5c1463 Code: 1f 84 00 00 00 00 00 83 ff 03 74 7b 83 ff 02 b8 fa ff ff ff 49 89 ca 0f 44 f8 80 3d fe 70 1d 00 00 74 14 b8 e6 00 00 00 0f 05 d8 c3 66 2e 0f 1f 84 00 00 00 00 00 48 83 ec 28 48 89 54 24 10 RSP: 002b:00007fffcbe5bc98 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd26b5c1463 RDX: 00007fffcbe5bcb0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 000000001c3dd561 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffcbe5c100 R13: 0000000000000004 R14: 00007fffcbe5bcec R15: 00007fffcbe5bd80