INFO: task kworker/u8:9:3522 blocked for more than 143 seconds. Not tainted 6.16.0-rc4-syzkaller-00324-g1f988d0788f5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:9 state:D stack:21560 pid:3522 tgid:3522 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-19) Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x724/0xe80 kernel/locking/mutex.c:747 bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2147 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x6ee/0xff0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x6b5/0x1000 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3321 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3402 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.5.116:6904 blocked for more than 144 seconds. Not tainted 6.16.0-rc4-syzkaller-00324-g1f988d0788f5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.116 state:D stack:20856 pid:6904 tgid:6902 ppid:6372 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 __closure_sync+0x163/0x220 lib/closure.c:146 bch2_wait_on_allocator fs/bcachefs/alloc_foreground.h:315 [inline] bch2_btree_update_start+0x18dc/0x1de0 fs/bcachefs/btree_update_interior.c:1293 bch2_btree_split_leaf+0x14b/0x8e0 fs/bcachefs/btree_update_interior.c:1921 bch2_trans_commit_error+0x1b7/0x1130 fs/bcachefs/btree_trans_commit.c:914 __bch2_trans_commit+0x1bb5/0x8870 fs/bcachefs/btree_trans_commit.c:1104 bch2_trans_commit fs/bcachefs/btree_update.h:241 [inline] __bch2_create+0x887/0xb90 fs/bcachefs/fs.c:593 bch2_mknod fs/bcachefs/fs.c:748 [inline] bch2_create+0x66/0xd0 fs/bcachefs/fs.c:762 vfs_create+0x24e/0x400 fs/namei.c:3414 do_mknodat+0x3c6/0x4d0 fs/namei.c:4294 __do_sys_mknod fs/namei.c:4327 [inline] __se_sys_mknod fs/namei.c:4325 [inline] __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4325 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7facd6d8e929 RSP: 002b:00007facd7b22038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085 RAX: ffffffffffffffda RBX: 00007facd6fb5fa0 RCX: 00007facd6d8e929 RDX: 0000000000000008 RSI: 0000000000000008 RDI: 00002000000001c0 RBP: 00007facd6e10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007facd6fb5fa0 R15: 00007fff3dadaa08 Showing all locks held in the system: 5 locks held by kworker/u8:1/13: 1 lock held by khungtaskd/31: #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 4 locks held by kworker/u8:9/3522: #0: ffff88801eaba948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801eaba948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321 #1: ffffc9000bacfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000bacfbc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321 #2: ffff88807d4920e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff888055579bf8 (&inode->ei_update_lock){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x6a/0xd0 fs/bcachefs/fs.c:2147 2 locks held by getty/5598: #0: ffff88814c8440a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 5 locks held by syz.5.116/6904: #0: ffff88807d492428 (sb_writers#22){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557 #1: ffff888055579810 (&sb->s_type->i_mutex_key#29/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline] #1: ffff888055579810 (&sb->s_type->i_mutex_key#29/1){+.+.}-{4:4}, at: filename_create+0x1f9/0x470 fs/namei.c:4148 #2: ffff888055579bf8 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x2f2/0xb90 fs/bcachefs/fs.c:567 #3: ffff888055984398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888055984398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888055984398 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3299 #4: ffff8880559a6710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x542/0x1de0 fs/bcachefs/btree_update_interior.c:1211 3 locks held by syz-executor/8696: #0: ffff888077b200e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff888077b200e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff888077b200e0 (&type->s_umount_key#72){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff88803f280278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xf8/0x900 fs/bcachefs/super.c:676 #2: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #2: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998 1 lock held by syz.5.373/9445: #0: ffff88807d4920e0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807d4920e0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x25c/0x3b0 fs/super.c:121 7 locks held by syz-executor/9751: #0: ffff888030994428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline] #0: ffff888030994428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 #1: ffff888023fcfc88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff888143ff7008 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8ed98c28 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:216 #4: ffff8880573500e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:884 [inline] #4: ffff8880573500e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1094 [inline] #4: ffff8880573500e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x7c0 drivers/base/dd.c:1292 #5: ffff888057351250 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786 5 locks held by syz.3.407/9959: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00324-g1f988d0788f5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 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:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] watchdog+0xfee/0x1030 kernel/hung_task.c:470 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 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: 8696 Comm: syz-executor Not tainted 6.16.0-rc4-syzkaller-00324-g1f988d0788f5 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:validate_chain+0x1/0x2140 kernel/locking/lockdep.c:3867 Code: 89 e6 4c 89 ff 29 f5 0f 82 91 fe ff ff eb b3 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 <41> 57 41 56 41 55 41 54 53 48 81 ec e0 00 00 00 49 89 cf 65 48 8b RSP: 0018:ffffc90000007518 EFLAGS: 00000086 RAX: ffffffff9345b8a8 RBX: 0000000000000005 RCX: e8a671c52ea5e4fd RDX: 0000000000000000 RSI: ffff8880276429b8 RDI: ffff888027641e00 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff81729af5 R10: ffffc90000007778 R11: ffffffff81acf5c0 R12: 0000000074f84309 R13: ffff8880276428f0 R14: ffff8880276429b8 R15: e8a671c52ea5e4fd FS: 000055557a1f2500(0000) GS:ffff888125c50000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055df3cdceaa8 CR3: 0000000066e2e000 CR4: 00000000003526f0 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:47 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:548 insert_work+0x3d/0x330 kernel/workqueue.c:2183 __queue_work+0xbd9/0xfe0 kernel/workqueue.c:2345 call_timer_fn+0x17b/0x5f0 kernel/time/timer.c:1747 expire_timers kernel/time/timer.c:1793 [inline] __run_timers kernel/time/timer.c:2372 [inline] __run_timer_base+0x646/0x860 kernel/time/timer.c:2384 run_timer_base kernel/time/timer.c:2393 [inline] run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403 handle_softirqs+0x283/0x870 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2061 [inline] RIP: 0010:vprintk_emit+0x58f/0x7a0 kernel/printk/printk.c:2449 Code: 85 32 01 00 00 e8 e1 63 1f 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 d0 63 1f 00 eb 06 e8 c9 63 1f 00 fb 48 c7 c7 a0 30 13 8e <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 c9 36 RSP: 0018:ffffc90003edf820 EFLAGS: 00000293 RAX: ffffffff81a0f9b7 RBX: ffffffff81a0f874 RCX: ffff888027641e00 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e1330a0 RBP: ffffc90003edf930 R08: ffffffff8fa0bef7 R09: 1ffffffff1f417de R10: dffffc0000000000 R11: fffffbfff1f417df R12: dffffc0000000000 R13: 1ffff920007dbf08 R14: 0000000000000200 R15: 0000000000000052 bch2_print_maybe_redirect fs/bcachefs/super.c:137 [inline] __bch2_print+0x176/0x220 fs/bcachefs/super.c:156 __bch2_fs_read_only+0x271/0x5b0 fs/bcachefs/super.c:299 bch2_fs_read_only+0x42a/0xb00 fs/bcachefs/super.c:366 __bch2_fs_stop+0x100/0x900 fs/bcachefs/super.c:677 generic_shutdown_super+0x135/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2618 deactivate_locked_super+0xb9/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1417 task_work_run+0x1d4/0x260 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f88d0f8fc57 Code: a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 0f 1f 44 00 00 31 f6 e9 09 00 00 00 66 0f 1f 84 00 00 00 00 00 b8 a6 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 RSP: 002b:00007ffc14118b38 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f88d1010925 RCX: 00007f88d0f8fc57 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc14118bf0 RBP: 00007ffc14118bf0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc14119c80 R13: 00007f88d1010925 R14: 00000000000554e2 R15: 00007ffc14119cc0