INFO: task syz-executor:14102 blocked for more than 143 seconds. Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:17416 pid:14102 tgid:14102 ppid:1 task_flags:0x400140 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5351 [inline] __schedule+0x1737/0x4d30 kernel/sched/core.c:6954 __schedule_loop kernel/sched/core.c:7036 [inline] schedule+0x165/0x360 kernel/sched/core.c:7051 schedule_timeout+0x9a/0x270 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2bf/0x5d0 kernel/sched/completion.c:153 kthread_stop+0x194/0x5c0 kernel/kthread.c:790 bch2_copygc_stop+0x4b/0x120 fs/bcachefs/movinggc.c:436 __bch2_fs_read_only+0x4a/0x4f0 fs/bcachefs/super.c:303 bch2_fs_read_only+0x403/0xa40 fs/bcachefs/super.c:389 __bch2_fs_stop+0xc9/0x8f0 fs/bcachefs/super.c:700 generic_shutdown_super+0x132/0x2c0 fs/super.c:643 bch2_kill_sb+0x41/0x50 fs/bcachefs/fs.c:2586 deactivate_locked_super+0xbc/0x130 fs/super.c:474 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1378 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:43 exit_to_user_mode_prepare include/linux/irq-entry-common.h:208 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0b89b8fcd7 RSP: 002b:00007ffc7412a9c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f0b89c10b55 RCX: 00007f0b89b8fcd7 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffc7412aa80 RBP: 00007ffc7412aa80 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc7412bb10 R13: 00007f0b89c10b55 R14: 00000000000de90c R15: 00007ffc7412bb50 Showing all locks held in the system: 1 lock held by rcu_tasks_trace/29: #0: ffffffff8e13e5d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{4:4}, at: rcu_tasks_one_gp+0xaf9/0xdf0 kernel/rcu/tasks.h:614 1 lock held by khungtaskd/31: #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e13d8a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770 2 locks held by getty/5610: #0: ffff88814dc6e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222 2 locks held by syz-executor/14102: #0: ffff88808d76c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88808d76c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88808d76c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffff888094a80278 (&c->state_lock){++++}-{4:4}, at: class_rwsem_write_constructor include/linux/rwsem.h:257 [inline] #1: ffff888094a80278 (&c->state_lock){++++}-{4:4}, at: __bch2_fs_stop+0xc1/0x8f0 fs/bcachefs/super.c:699 2 locks held by syz-executor/27451: #0: ffff8880b8639f98 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636 #1: ffff8880b8624008 (per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:937 2 locks held by bch-copygc/loop/29378: #0: ffff888094a843a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #0: ffff888094a843a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #0: ffff888094a843a8 (&c->btree_trans_barrier){.+.+}-{0:0}, at: bch2_trans_srcu_lock+0xaf/0x220 fs/bcachefs/btree_iter.c:3293 #1: ffff888094aa6710 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x53f/0x1e00 fs/bcachefs/btree_update_interior.c:1196 3 locks held by kworker/u8:58/32178: #0: ffff88814cc52148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88814cc52148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000be7fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000be7fbc0 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x112/0x14b0 net/ipv6/addrconf.c:4189 4 locks held by kworker/u8:62/32182: #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88801a489148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000bf37bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000bf37bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303 #3: ffffffff8e143338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #3: ffffffff8e143338 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:967 1 lock held by syz.9.9280/1562: #0: ffff88808d76c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline] #0: ffff88808d76c0e0 (&type->s_umount_key#59){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121 2 locks held by syz-executor/1651: #0: ffff88807a6f00e0 (&type->s_umount_key#77){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline] #0: ffff88807a6f00e0 (&type->s_umount_key#77){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline] #0: ffff88807a6f00e0 (&type->s_umount_key#77){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506 #1: ffffffff8e143200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 1 lock held by syz-executor/2844: #0: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f525e88 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8db/0x1c70 net/core/rtnetlink.c:4056 7 locks held by syz-executor/2890: #0: ffff88807d204428 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3107 [inline] #0: ffff88807d204428 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682 #1: ffff888081da4088 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325 #2: ffff8880273e5e18 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x203/0x4f0 fs/kernfs/file.c:326 #3: ffffffff8edb46c8 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234 #4: ffff88805562c0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:911 [inline] #4: ffff88805562c0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline] #4: ffff88805562c0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294 #5: ffff88807ad20250 (&devlink->lock_key#10){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1718 #6: ffffffff8e143200 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3815 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc6-next-20250718-syzkaller #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:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:328 [inline] watchdog+0xf93/0xfe0 kernel/hung_task.c:491 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3f9/0x770 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: 2890 Comm: syz-executor Not tainted 6.16.0-rc6-next-20250718-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__bfs kernel/locking/lockdep.c:1818 [inline] RIP: 0010:__bfs_backwards kernel/locking/lockdep.c:1863 [inline] RIP: 0010:check_irq_usage kernel/locking/lockdep.c:2799 [inline] RIP: 0010:check_prev_add kernel/locking/lockdep.c:3172 [inline] RIP: 0010:check_prevs_add kernel/locking/lockdep.c:3287 [inline] RIP: 0010:validate_chain+0xfd7/0x2140 kernel/locking/lockdep.c:3911 Code: 25 ff 0f 00 00 39 05 64 ce 0d 12 73 06 89 05 5c ce 0d 12 49 8b 04 24 48 89 de 48 39 e8 0f 84 33 fe ff ff 4c 89 68 30 48 8b 00 <48> 39 e8 75 f4 48 89 de e9 1f fe ff ff 48 c7 c7 50 e6 00 8e 48 89 RSP: 0018:ffffc9000b3ff1b8 EFLAGS: 00000006 RAX: ffffffff963c0ba8 RBX: 00000000000003dd RCX: 000000000000047c RDX: 0000000000000008 RSI: 00000000000003dd RDI: ffff88802e39da00 RBP: ffffffff934cbdf8 R08: ffffc9000b3ff180 R09: 0000000000000020 R10: ffff88801cea0098 R11: ffffffff819dd480 R12: ffffffff962f1d88 R13: ffffffff962f7c78 R14: ffff88802e39e680 R15: 000000000000047b FS: 000055557a686500(0000) GS:ffff888125be3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8c1ff83178 CR3: 000000002475c000 CR4: 00000000003526f0 Call Trace: __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5240 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 do_write_seqcount_begin_nested include/linux/seqlock.h:477 [inline] do_write_seqcount_begin include/linux/seqlock.h:503 [inline] psi_write_begin+0xab/0x160 kernel/sched/psi.c:183 psi_task_change+0xd9/0x340 kernel/sched/psi.c:923 psi_enqueue kernel/sched/stats.h:166 [inline] enqueue_task+0x343/0x420 kernel/sched/core.c:2086 activate_task kernel/sched/core.c:2126 [inline] ttwu_do_activate+0x1f3/0x870 kernel/sched/core.c:3735 ttwu_queue kernel/sched/core.c:3998 [inline] try_to_wake_up+0x721/0x12b0 kernel/sched/core.c:4322 kick_pool+0x47d/0x640 kernel/workqueue.c:1283 __queue_work+0xcdf/0xfb0 kernel/workqueue.c:2340 queue_work_on+0x181/0x270 kernel/workqueue.c:2390 queue_work include/linux/workqueue.h:669 [inline] schedule_work include/linux/workqueue.h:730 [inline] ref_tracker_debugfs_mark lib/ref_tracker.c:63 [inline] ref_tracker_dir_exit+0x13e/0x640 lib/ref_tracker.c:231 free_netdev+0x46d/0x700 net/core/dev.c:11941 __nsim_dev_port_del+0x14d/0x1b0 drivers/net/netdevsim/dev.c:1471 nsim_dev_port_del_all drivers/net/netdevsim/dev.c:1483 [inline] nsim_dev_reload_destroy+0x288/0x490 drivers/net/netdevsim/dev.c:1704 nsim_drv_remove+0x58/0x160 drivers/net/netdevsim/dev.c:1719 device_remove drivers/base/dd.c:569 [inline] __device_release_driver drivers/base/dd.c:1274 [inline] device_release_driver_internal+0x46c/0x800 drivers/base/dd.c:1297 bus_remove_device+0x34d/0x410 drivers/base/bus.c:579 device_del+0x511/0x8e0 drivers/base/core.c:3878 device_unregister+0x20/0xc0 drivers/base/core.c:3919 nsim_bus_dev_del drivers/net/netdevsim/bus.c:483 [inline] del_device_store+0x2aa/0x360 drivers/net/netdevsim/bus.c:244 kernfs_fop_write_iter+0x378/0x4f0 fs/kernfs/file.c:334 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x548/0xa90 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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: 0033:0x7f126e38d45f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007fff1f482c80 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007f126e38d45f RDX: 0000000000000001 RSI: 00007fff1f482cd0 RDI: 0000000000000005 RBP: 00007f126e411fbd R08: 0000000000000000 R09: 00007fff1f482ad7 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007fff1f482cd0 R14: 00007f126f0e4620 R15: 0000000000000003