INFO: task kworker/1:0:22 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:0 state:D stack:23912 pid:22 ppid:2 flags:0x00004000 Workqueue: events_long flush_old_commits Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline] flush_old_commits+0x1de/0x2f0 fs/reiserfs/super.c:111 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 INFO: task syz-executor:4364 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22144 pid:4364 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 reiserfs_readdir_inode+0x164/0x1230 fs/reiserfs/dir.c:79 iterate_dir+0x218/0x560 fs/readdir.c:-1 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0xe5/0x260 fs/readdir.c:354 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f87625c20b3 RSP: 002b:00007ffdeb0610b8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 000055558450c600 RCX: 00007f87625c20b3 RDX: 0000000000008000 RSI: 000055558450c600 RDI: 0000000000000005 RBP: 000055558450c5d4 R08: 0000000000028a41 R09: 0000000000000000 R10: 00007f87627bacc0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 000055558450c5d0 R15: 00007ffdeb063370 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8c92c2d0 ( rcu_tasks_trace.tasks_gp_mutex ){+.+.}-{3:3} , at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 4 locks held by kworker/0:1/14: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000137d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888023d100e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88807e8a4090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/1:0/22: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900001c7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888074ac20e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88807b623090 ( &sbi->lock ){+.+.}-{3:3} , at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 1 lock held by khungtaskd/27: #0: ffffffff8c92b120 ( rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 5 locks held by kworker/u4:4/75: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90001597d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db2e6d0 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594 #3: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_delete_nets+0xc8/0x360 net/ipv4/ip_tunnel.c:1152 #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 1 lock held by dhcpcd/3931: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305 2 locks held by getty/4030: #0: ffff88814d8e3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 4 locks held by kworker/1:3/4301: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900041a7d00 ( (work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88805a8320e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88807bf39090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz-executor/4364: #0: ffff888079175268 (&f->f_pos_lock ){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88806a3702e0 (&type->i_mutex_dir_key#8 ){++++}-{3:3} , at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff88807b623090 (&sbi->lock ){+.+.}-{3:3} , at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/0:24/4432: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900034d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88805c6900e0 (&type->s_umount_key #52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff888026698090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/0:27/4435: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003507d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880627220e0 (&type->s_umount_key #52 ){++++}-{3:3} , at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88801c699090 ( &sbi->lock ){+.+.}-{3:3} , at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.0.17/4440: 3 locks held by syz-executor/4451: #0: ffff88802856d4e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88806a370980 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff88807e8a4090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.1.19/4472: 3 locks held by syz.3.25/4605: 3 locks held by syz-executor/4700: #0: ffff88807f4dc868 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88806a371d60 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff888026698090 ( &sbi->lock ){+.+.}-{3:3} , at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.4.26/4814: 3 locks held by syz-executor/4821: #0: ffff888024700ae8 ( &f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff88805bc6a400 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff88807bf39090 ( &sbi->lock ){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.5.28/4849: 1 lock held by syz-executor/4894: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 2 locks held by kworker/1:6/4899: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003217d00 ( (work_completion)(&rew->rew_work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376