INFO: task kworker/u8:5:1327 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:5 state:D stack:20216 pid:1327 tgid:1327 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-bcachefs-11) Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1ac3/0x5090 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6896 __mutex_lock_common kernel/locking/mutex.c:664 [inline] __mutex_lock+0x7fa/0x1000 kernel/locking/mutex.c:732 bch2_vfs_write_inode+0x69/0xc0 fs/bcachefs/fs.c:1834 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x822/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x429/0xb90 fs/fs-writeback.c:2158 wb_check_start_all fs/fs-writeback.c:2284 [inline] wb_do_writeback fs/fs-writeback.c:2310 [inline] wb_workfn+0x99b/0x10b0 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 INFO: task syz.2.96:6990 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.96 state:D stack:24776 pid:6990 tgid:6989 ppid:5822 task_flags:0x400140 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5366 [inline] __schedule+0x1ac3/0x5090 kernel/sched/core.c:6747 __schedule_loop kernel/sched/core.c:6824 [inline] schedule+0x163/0x360 kernel/sched/core.c:6839 wb_wait_for_completion+0x166/0x270 fs/fs-writeback.c:216 sync_inodes_sb+0x28f/0xb50 fs/fs-writeback.c:2821 iterate_supers+0xc6/0x190 fs/super.c:934 ksys_sync+0xc2/0x1d0 fs/sync.c:102 __do_sys_sync+0xe/0x20 fs/sync.c:113 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f823558d169 RSP: 002b:00007f8236364038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 00007f82357a5fa0 RCX: 00007f823558d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007f82357a5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f82357a5fa0 R15: 00007ffea99238f8 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: 1 lock held by khungtaskd/31: #0: ffffffff8eb3a860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb3a860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb3a860 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x30/0x180 kernel/locking/lockdep.c:6761 3 locks held by kworker/u8:3/54: #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801ac89148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000bf7c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:285 3 locks held by kworker/0:2/975: #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801ac80d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc90003a37c60 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90003a37c60 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104 4 locks held by kworker/u8:5/1327: #0: ffff88801dedb948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801dedb948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc900044c7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc900044c7c60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88805e8e1bf8 (&inode->ei_update_lock){+.+.}-{4:4}, at: bch2_vfs_write_inode+0x69/0xc0 fs/bcachefs/fs.c:1834 3 locks held by kworker/u8:6/2941: #0: ffff88814d34a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814d34a148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000c13fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000c13fc60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #2: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x110/0x16a0 net/ipv6/addrconf.c:4190 3 locks held by kworker/u8:9/3497: #0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801baf3948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x990/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000ce8fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000ce8fc60 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9cb/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb3fc40 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 1 lock held by syslogd/5179: #0: ffff8880b8639958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:595 1 lock held by dhcpcd/5491: #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd6a/0x1f60 net/core/rtnetlink.c:4021 2 locks held by getty/5583: #0: ffff88814d46b0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033332f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x53d/0x16b0 drivers/tty/n_tty.c:2211 5 locks held by syz.5.49/6383: #0: ffff88805593e420 (sb_writers#17){.+.+}-{0:0}, at: mnt_want_write+0x3f/0x90 fs/namespace.c:556 #1: ffff88805e8e1810 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:902 [inline] #1: ffff88805e8e1810 (&sb->s_type->i_mutex_key#24/1){+.+.}-{4:4}, at: filename_create+0x266/0x490 fs/namei.c:4097 #2: ffff88805e8e1bf8 (&inode->ei_update_lock){+.+.}-{4:4}, at: __bch2_create+0x359/0xf40 fs/bcachefs/fs.c:550 #3: ffff88806a984378 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff88806a984378 (&c->btree_trans_barrier){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff88806a984378 (&c->btree_trans_barrier){.+.+}-{0:0}, at: __bch2_trans_get+0x7ed/0xd40 fs/bcachefs/btree_iter.c:3408 #4: ffff88806a9a66d0 (&c->gc_lock){++++}-{4:4}, at: bch2_btree_update_start+0x68a/0x1680 fs/bcachefs/btree_update_interior.c:1182 2 locks held by syz.2.96/6990: #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.3.215/8315: #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2819 2 locks held by syz.7.287/9245: #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88805593e0e0 (&type->s_umount_key#61){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880593867d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x270/0xb50 fs/fs-writeback.c:2819 1 lock held by syz-executor/10339: #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x7da/0xf40 net/ipv6/addrconf.c:5023 8 locks held by syz-executor/10354: #0: ffff88803658e420 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3033 [inline] #0: ffff88803658e420 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x23f/0xd10 fs/read_write.c:680 #1: ffff8880227f0488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ef/0x510 fs/kernfs/file.c:325 #2: ffff8880279284b8 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x213/0x510 fs/kernfs/file.c:326 #3: ffffffff8f76ab28 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfe/0x490 drivers/net/netdevsim/bus.c:216 #4: ffff8880260ed0e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:922 [inline] #4: ffff8880260ed0e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff8880260ed0e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff8880260ee250 (&devlink->lock_key#15){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xa4/0x620 drivers/net/netdevsim/netdev.c:1016 #7: ffffffff8eb3fd78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline] #7: ffffffff8eb3fd78 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x454/0x830 kernel/rcu/tree_exp.h:998 1 lock held by syz-executor/10509: #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #0: ffffffff8fec2588 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xd6a/0x1f60 net/core/rtnetlink.c:4021 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-03576-g1e1ba8d23dae #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x4ab/0x4e0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline] NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111