INFO: task kworker/u8:6:3455 blocked for more than 143 seconds. Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:6 state:D stack:19000 pid:3455 tgid:3455 ppid:2 task_flags:0x4208060 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6914 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 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+0x70a/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_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xb94/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Showing all locks held in the system: 3 locks held by kworker/u8:1/13: #0: ffff88814cf99948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88814cf99948 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90000127c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90000127c60 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #2: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x10e/0x16a0 net/ipv6/addrconf.c:4190 1 lock held by khungtaskd/31: #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8eb393e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 2 locks held by kworker/u8:4/63: #0: ffff8880b863e958 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:598 #1: ffffc90001557c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90001557c60 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 4 locks held by kworker/u8:6/3455: #0: ffff888143edd148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888143edd148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000d21fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000d21fc60 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffff88814476c0e0 (&type->s_umount_key#93){++++}-{4:4}, at: super_trylock_shared+0x22/0xf0 fs/super.c:562 #3: ffff888078322fe0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x24a/0x590 fs/jfs/inode.c:102 2 locks held by getty/5588: #0: ffff8880317cc0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900033132f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 3 locks held by kworker/0:5/5897: #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff88801b078d48 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc90004247c60 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc90004247c60 ((fqdir_free_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb3e780 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3741 4 locks held by syz.3.117/6511: 2 locks held by syz.4.330/8533: #0: ffff88814476c0e0 (&type->s_umount_key#93){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88814476c0e0 (&type->s_umount_key#93){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880257cc7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880257cc7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 1 lock held by syz-executor/8737: #0: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:129 [inline] #0: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x47e/0x1bc0 net/ipv4/devinet.c:987 2 locks held by syz-executor/8933: #0: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #0: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #0: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4021 #1: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:302 [inline] #1: ffffffff8eb3e8b8 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x381/0x820 kernel/rcu/tree_exp.h:996 2 locks held by syz-executor/9118: #0: ffffffff8f64c500 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8f64c500 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8f64c500 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:564 #1: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #1: ffffffff8fed5d08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4021 2 locks held by syz.6.374/9470: #0: ffff88814476c0e0 (&type->s_umount_key#93){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline] #0: ffff88814476c0e0 (&type->s_umount_key#93){++++}-{4:4}, at: super_lock+0x27c/0x400 fs/super.c:120 #1: ffff8880257cc7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline] #1: ffff8880257cc7d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x26e/0xb50 fs/fs-writeback.c:2819 3 locks held by syz.7.389/10129: #0: ffff88806018fc70 (&fc->uapi_mutex){+.+.}-{4:4}, at: __do_sys_fsconfig fs/fsopen.c:465 [inline] #0: ffff88806018fc70 (&fc->uapi_mutex){+.+.}-{4:4}, at: __se_sys_fsconfig+0x9b2/0xf60 fs/fsopen.c:344 #1: ffff888055f060e0 (&type->s_umount_key#109/1){+.+.}-{4:4}, at: alloc_super+0x221/0x9d0 fs/super.c:344 #2: ffff8880359e0090 (&client->mount_mutex){+.+.}-{4:4}, at: ceph_real_mount fs/ceph/super.c:1161 [inline] #2: ffff8880359e0090 (&client->mount_mutex){+.+.}-{4:4}, at: ceph_get_tree+0x886/0x17b0 fs/ceph/super.c:1355 6 locks held by cmp/10139: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 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+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:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 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: 5997 Comm: kworker/0:6 Not tainted 6.14.0-rc6-syzkaller-00016-g0fed89a961ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: ceph-msgr ceph_con_workfn RIP: 0010:suppress_message_printing kernel/printk/printk.c:1311 [inline] RIP: 0010:printk_get_next_message+0x2d9/0x8b0 kernel/printk/printk.c:3000 Code: 0f b6 1b 89 de 83 e6 01 31 ff e8 c2 0f 21 00 f6 c3 01 4c 8b 74 24 40 75 44 80 7c 24 5c 00 74 3d c1 eb 05 44 8b 2d 57 78 00 0d <44> 89 ef 89 de e8 5d 0e 21 00 41 39 dd 0f 8e 14 03 00 00 e8 8f 0c RSP: 0018:ffffc900043e6f60 EFLAGS: 00000212 RAX: 0000000000000000 RBX: 0000000000000004 RCX: fcfae611a98edb00 RDX: ffff888030811e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900043e7150 R08: ffffffff81a0d24e R09: ffffffff81a228f8 R10: 0000000000000003 R11: ffff888030811e00 R12: ffffc900043e7040 R13: 000000000000000f R14: ffffc900043e7260 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcb0813c440 CR3: 000000007a150000 CR4: 0000000000350ef0 Call Trace: console_emit_next_record kernel/printk/printk.c:3076 [inline] console_flush_all+0x569/0xeb0 kernel/printk/printk.c:3210 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline] console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432 _printk+0xd5/0x120 kernel/printk/printk.c:2457 ceph_tcp_connect+0x628/0x8e0 net/ceph/messenger.c:469 ceph_con_v1_try_write+0x3ac/0x39a0 net/ceph/messenger_v1.c:1497 ceph_con_workfn+0x2ab/0x10f0 net/ceph/messenger.c:1589 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd30 kernel/workqueue.c:3400 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244