INFO: task kworker/u8:4:62 blocked for more than 143 seconds. Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:4 state:D stack:21744 pid:62 tgid:62 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:1) Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6905 __mutex_lock_common kernel/locking/mutex.c:665 [inline] __mutex_lock+0x7e7/0xee0 kernel/locking/mutex.c:735 jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 jfs_write_inode+0x143/0x220 fs/jfs/inode.c:132 write_inode fs/fs-writeback.c:1525 [inline] __writeback_single_inode+0x708/0x10d0 fs/fs-writeback.c:1745 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_background_flush fs/fs-writeback.c:2228 [inline] wb_do_writeback fs/fs-writeback.c:2316 [inline] wb_workfn+0xc4b/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 2 locks held by kworker/u8:1/12: #0: ffff88801df7a948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801df7a948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 1 lock held by khungtaskd/30: #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937ae0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6744 2 locks held by kworker/u8:2/35: #0: ffff8880b863e758 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #1: ffff8880b8628948 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x41d/0x7a0 kernel/sched/psi.c:987 6 locks held by kworker/u8:3/53: #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baeb148 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc90000bd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffffffff8fc94350 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0x16a/0xd50 net/core/net_namespace.c:602 #3: ffffffff8fca0808 (rtnl_mutex){+.+.}-{4:4}, at: wg_netns_pre_exit+0x1f/0x1e0 drivers/net/wireguard/device.c:415 #4: ffff88805da394e8 (&wg->device_update_lock){+.+.}-{4:4}, at: wg_netns_pre_exit+0xba/0x1e0 drivers/net/wireguard/device.c:420 #5: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #5: ffffffff8e93cff8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 4 locks held by kworker/u8:4/62: #0: ffff8880206ac948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff8880206ac948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1840 kernel/workqueue.c:3310 #1: ffffc9000153fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc9000153fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1840 kernel/workqueue.c:3310 #2: ffff8880798840e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff88805e2581c8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 5 locks held by kworker/u8:7/3641: 1 lock held by dhcpcd/5487: #0: ffffffff8fca0808 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:128 [inline] #0: ffffffff8fca0808 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bd0 net/ipv4/devinet.c:987 2 locks held by getty/5572: #0: ffff8880313b50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002fde2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 4 locks held by syz.1.18/5971: 2 locks held by syz.3.42/6174: #0: ffff8880798840e0 (&type->s_umount_key#74){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff8880798840e0 (&type->s_umount_key#74){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880257a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880257a07d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 7 locks held by syz-executor/7461: #0: ffff888023cd6420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2964 [inline] #0: ffff888023cd6420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x225/0xd30 fs/read_write.c:675 #1: ffff88802983e488 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1ea/0x500 fs/kernfs/file.c:325 #2: ffff888144bde788 (kn->active#49){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x20e/0x500 fs/kernfs/file.c:326 #3: ffffffff8f54c468 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xfc/0x480 drivers/net/netdevsim/bus.c:216 #4: ffff88805f5220e8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline] #4: ffff88805f5220e8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1095 [inline] #4: ffff88805f5220e8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xce/0x7c0 drivers/base/dd.c:1293 #5: ffff88805f523250 (&devlink->lock_key){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1675 #6: ffffffff8fca0808 (rtnl_mutex){+.+.}-{4:4}, at: unregister_netdevice_notifier_net+0x89/0x3a0 net/core/dev.c:1917 2 locks held by syz.0.165/7585: #0: ffffffff8f0417e8 (bio_slab_lock){+.+.}-{4:4}, at: bio_put_slab block/bio.c:140 [inline] #0: ffffffff8f0417e8 (bio_slab_lock){+.+.}-{4:4}, at: bioset_exit+0x42f/0x650 block/bio.c:1755 #1: ffffffff8e93cec0 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4565 2 locks held by syz.7.170/7597: #0: ffff88807ab080e0 (&type->s_umount_key#71/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344 #1: ffffffff8e7e3168 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5166 [inline] #1: ffffffff8e7e3168 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa55/0x1f20 kernel/workqueue.c:5720 2 locks held by syz.8.171/7620: #0: ffff88804ce280e0 (&type->s_umount_key#71/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344 #1: ffffffff8e7e3168 (wq_pool_mutex){+.+.}-{4:4}, at: apply_wqattrs_lock kernel/workqueue.c:5166 [inline] #1: ffffffff8e7e3168 (wq_pool_mutex){+.+.}-{4:4}, at: __alloc_workqueue+0xa55/0x1f20 kernel/workqueue.c:5720 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:234 [inline] watchdog+0xff6/0x1040 kernel/hung_task.c:397 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5805 Comm: syz-executor Not tainted 6.13.0-rc5-syzkaller-00004-gccb98ccef0e5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline] RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline] RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] RIP: 0010:do_raw_spin_lock+0x16f/0x370 kernel/locking/spinlock_debug.c:116 Code: be 04 00 00 00 e8 41 3a 87 00 41 0f b6 44 1d 00 84 c0 48 89 da 0f 85 8d 01 00 00 8b 44 24 60 b9 01 00 00 00 f0 41 0f b1 0c 24 <0f> 85 df 00 00 00 65 8b 1d b0 bb 87 7e 41 0f b6 04 17 84 c0 0f 85 RSP: 0018:ffffc900036b7a80 EFLAGS: 00000046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffffc900036b7ae0 RBP: ffffc900036b7b50 R08: 0000000000000003 R09: fffff520006d6f5c R10: dffffc0000000000 R11: fffff520006d6f5c R12: ffffffff9a55b478 R13: 1ffff920006d6f5c R14: ffffc900036b7ae0 R15: 1ffffffff34ab690 FS: 000055558f584500(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555a04853780 CR3: 000000001218c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 __debug_object_init+0xec/0x470 lib/debugobjects.c:741 debug_hrtimer_init_on_stack kernel/time/hrtimer.c:422 [inline] debug_init_on_stack kernel/time/hrtimer.c:462 [inline] hrtimer_setup_sleeper_on_stack kernel/time/hrtimer.c:2046 [inline] hrtimer_nanosleep+0xb0/0x410 kernel/time/hrtimer.c:2124 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1402 [inline] __se_sys_clock_nanosleep+0x32b/0x3c0 kernel/time/posix-timers.c:1379 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc8f7bb85a3 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 9e 3f 19 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:00007ffd21319458 EFLAGS: 00000202 ORIG_RAX: 00000000000000e6 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc8f7bb85a3 RDX: 00007ffd21319470 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 000000003345a4cf R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd213198c0 R13: 0000000000000004 R14: 00007ffd213194ac R15: 00007ffd21319540