INFO: task kworker/1:3:3652 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:3 state:D stack:25184 pid:3652 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:4381 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:22048 pid:4381 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: 0033:0x7f1b2efc20b3 RSP: 002b:00007ffc1376dae8 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 00005555830da600 RCX: 00007f1b2efc20b3 RDX: 0000000000008000 RSI: 00005555830da600 RDI: 0000000000000005 RBP: 00005555830da5d4 R08: 0000000000028a41 R09: 0000000000000000 R10: 00007f1b2f1bacc0 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 00005555830da5d0 R15: 00007ffc1376fda0 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 3 locks held by kworker/0:1/14: #0: ffff88802f474938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000137d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131 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: ffff888019a620e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff88801e2fb090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 1 lock held by khungtaskd/28: #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8c92b120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by kworker/u4:2/33: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000aa7d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263 #3: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #3: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 4 locks held by kworker/0:2/125: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90002de7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880554120e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff888074af7090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/1:3/3652: #0: ffff888017471138 ( (wq_completion)events_long ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900033d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807ab480e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff8880767e5090 ( &sbi->lock ){+.+.}-{3:3} , at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 1 lock held by dhcpcd/3932: #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 getty/4022: #0: ffff888030539098 ( &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/1:4/4319: #0: ffff88802f474938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003f27d00 ((work_completion)(&(&net->ipv6.addr_chk_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 ( rtnl_mutex){+.+.}-{3:3}, at: addrconf_verify_work+0x15/0x30 net/ipv6/addrconf.c:4672 4 locks held by kworker/0:4/4321: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90003f47d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88805b99c0e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff888026440090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz-executor/4381: #0: ffff888026c80ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888060ea02e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff8880767e5090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 2 locks held by kworker/1:5/4390: #0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900032c7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by syz.0.17/4450: 3 locks held by syz-executor/4484: #0: ffff88807bd42ae8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888060fb82e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff88801e2fb090 ( &sbi->lock ){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.2.22/4574: 3 locks held by syz-executor/4678: #0: ffff88807c8cf768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888060ea1d60 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff888026440090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/1:6/4728: #0: ffff888017471138 ( (wq_completion)events_long ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004697d00 ( (work_completion)(&(&sbi->old_work)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880736ac0e0 (&type->s_umount_key#52){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff888061484090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.3.24/4772: 3 locks held by syz-executor/4789: #0: ffff88802e840d68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888060fb96c0 ( &type->i_mutex_dir_key #8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff888074af7090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.4.26/4827: 3 locks held by syz-executor/4867: #0: ffff88807b21f768 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ae/0x360 fs/file.c:1038 #1: ffff888060ea37e0 (&type->i_mutex_dir_key#8){++++}-{3:3}, at: iterate_dir+0x10d/0x560 fs/readdir.c:55 #2: ffff888061484090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.6.32/4969: 1 lock held by syz-executor/5057: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 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: 4450 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 a2 7e 09 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 d3 af 59 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc9000366dd38 EFLAGS: 00000006 RAX: 1ffffffff2daac05 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc9000366df30 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520006cdb88 R11: 1ffff920006cdb88 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff96d56480 R15: 0000000000000000 FS: 00005555830bf500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564f4b354d08 CR3: 0000000076ab9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:668 [inline] serial8250_console_write+0x247/0x17a0 drivers/tty/serial/8250/8250_port.c:3437 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 __reiserfs_warning+0x14e/0x1a0 fs/reiserfs/prints.c:290 reiserfs_read_bitmap_block+0x24c/0x730 fs/reiserfs/bitmap.c:1434 scan_bitmap_block+0x1ad/0xde0 fs/reiserfs/bitmap.c:164 scan_bitmap fs/reiserfs/bitmap.c:402 [inline] allocate_without_wrapping_disk fs/reiserfs/bitmap.c:1161 [inline] blocknrs_and_prealloc_arrays_from_search_start fs/reiserfs/bitmap.c:1274 [inline] reiserfs_allocate_blocknrs+0x367a/0x53b0 fs/reiserfs/bitmap.c:1375 _allocate_block fs/reiserfs/inode.c:-1 [inline] reiserfs_get_block+0x266f/0x3ef0 fs/reiserfs/inode.c:756 __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 __kernel_write_iter+0x26d/0x630 fs/read_write.c:517 __kernel_write+0xec/0x140 fs/read_write.c:537 __dump_emit+0x202/0x310 fs/coredump.c:873 elf_core_dump+0x2734/0x3490 fs/binfmt_elf.c:2306 do_coredump+0x15ff/0x22b0 fs/coredump.c:824 get_signal+0x10aa/0x1350 kernel/signal.c:2857 arch_do_signal_or_restart+0xb7/0x1240 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:316 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1490 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f1b2ef8f751 Code: 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 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f RSP: 002b:fffffffffffffe80 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f1b2f1e5fa0 RCX: 00007f1b2ef8f749 RDX: 0000000000000000 RSI: fffffffffffffe80 RDI: 0000000000008000 RBP: 00007f1b2f013f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 00007f1b2f1e5fa0 R14: 00007f1b2f1e5fa0 R15: 0000000000000006