INFO: task kworker/1:8:4392 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:8 state:D stack:25568 pid:4392 ppid:2 flags:0x00004000 Workqueue: events_long flush_old_commits Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6697 __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 Showing all locks held in the system: 3 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8c92bb70 (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: ffffffff8c92c390 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 3 locks held by kworker/1:0/22: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900001c7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888031730240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26b/0x32b0 drivers/net/netdevsim/fib.c:1491 1 lock held by khungtaskd/27: #0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b1e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 3 locks held by kworker/u4:3/46: no locks held by klogd/3626. 2 locks held by getty/4028: #0: ffff88814d34b098 (&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 3 locks held by kworker/0:7/4368: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004aa7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880545d6240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26b/0x32b0 drivers/net/netdevsim/fib.c:1491 4 locks held by kworker/1:8/4392: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004b37d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807dbfe0e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88807307a090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by kworker/0:16/4844: #0: ffff88814cf9bd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000caffd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 1 lock held by syz-executor/5353: #0: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #0: ffffffff8c930eb8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 4 locks held by syz.5.355/5942: 3 locks held by kworker/1:19/6637: #0: ffff88814cf9bd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004f5fd00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3bfe8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 6 locks held by syz-executor/6969: ============================================= 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 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 5942 Comm: syz.5.355 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:direntry_part_size+0x9c/0x1a0 fs/reiserfs/item_ops.c:593 Code: 85 da 00 00 00 4c 89 f8 48 c1 e8 03 0f b6 04 10 84 c0 0f 85 f0 00 00 00 0f b7 1b 44 29 f3 eb 05 e8 79 10 67 ff 41 8d 6c 1e ff <89> df 89 ee e8 cb 11 67 ff 39 eb 7e 0d e8 62 10 67 ff 45 31 f6 e9 RSP: 0018:ffffc9000d916ae8 EFLAGS: 00000293 RAX: ffffffff8219f947 RBX: 0000000000000000 RCX: ffff888019bbd940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000ffffffff R08: 0000000000000000 R09: 00000000ffffffff R10: 00000000ffffffff R11: 0000000000000000 R12: ffff888053560080 R13: ffff8880535600d0 R14: 0000000000000000 R15: dffffc0000000000 FS: 00007f4c0b0ce6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055557a11a5c8 CR3: 0000000077695000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: get_num_ver+0x40d/0xfd0 fs/reiserfs/fix_node.c:471 ip_check_balance fs/reiserfs/fix_node.c:1523 [inline] check_balance fs/reiserfs/fix_node.c:2083 [inline] fix_nodes+0x2867/0x82d0 fs/reiserfs/fix_node.c:2635 reiserfs_paste_into_item+0x5c8/0x7e0 fs/reiserfs/stree.c:2130 reiserfs_get_block+0x1bdc/0x3ef0 fs/reiserfs/inode.c:1069 __block_write_begin_int+0x54b/0x1a70 fs/buffer.c:1991 reiserfs_write_begin+0x206/0x4c0 fs/reiserfs/inode.c:2775 generic_perform_write+0x2f7/0x5a0 mm/filemap.c:3862 __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4c0a18f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4c0b0ce038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f4c0a3e5fa0 RCX: 00007f4c0a18f749 RDX: 0000000000000009 RSI: 0000200000000000 RDI: 0000000000000006 RBP: 00007f4c0a213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4c0a3e6038 R14: 00007f4c0a3e5fa0 R15: 00007ffdd50ebb48