INFO: task kworker/1:0:23 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:24952 pid:23 ppid:2 flags:0x00004000 Workqueue: events_long flush_old_commits Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27 reiserfs_sync_fs fs/reiserfs/super.c:76 [inline] flush_old_commits+0x1e2/0x2f0 fs/reiserfs/super.c:111 process_one_work kernel/workqueue.c:2634 [inline] process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 INFO: task syz.0.26:5969 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.26 state:D stack:24688 pid:5969 ppid:5885 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6833 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747 reiserfs_write_lock_nested+0x60/0xd0 fs/reiserfs/lock.c:78 reiserfs_paste_into_item+0x1b4/0x7f0 fs/reiserfs/stree.c:2111 reiserfs_add_entry+0x978/0xd90 fs/reiserfs/namei.c:565 reiserfs_create+0x53f/0x680 fs/reiserfs/namei.c:676 lookup_open fs/namei.c:3496 [inline] open_last_lookups fs/namei.c:3564 [inline] path_openat+0x1277/0x3190 fs/namei.c:3794 do_filp_open+0x1c5/0x3d0 fs/namei.c:3824 do_sys_openat2+0x12c/0x1c0 fs/open.c:1421 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x139/0x160 fs/open.c:1447 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6a1e98f749 RSP: 002b:00007f6a1f8de038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f6a1ebe6090 RCX: 00007f6a1e98f749 RDX: 000000000000275a RSI: 0000200000000140 RDI: ffffffffffffff9c RBP: 00007f6a1ea13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6a1ebe6128 R14: 00007f6a1ebe6090 R15: 00007fff882fb918 Showing all locks held in the system: 4 locks held by kworker/1:0/23: #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900001d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900001d7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88807a46c0e0 (&type->s_umount_key#25){++++}-{3:3}, at: flush_old_commits+0xcc/0x2f0 fs/reiserfs/super.c:97 #3: ffff88807b0e4090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27 1 lock held by khungtaskd/29: #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2ffa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633 2 locks held by kworker/u4:4/59: #0: ffff8880b8e3c018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:559 #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline] #1: ffff8880b8e289c0 (psi_seq){-.-.}-{0:0}, at: __schedule+0x20ee/0x44d0 kernel/sched/core.c:6695 4 locks held by kworker/0:2/967: #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900043f7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900043f7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88805f82e0e0 (&type->s_umount_key#25){++++}-{3:3}, at: flush_old_commits+0xcc/0x2f0 fs/reiserfs/super.c:97 #3: ffff88801b7f6090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27 2 locks held by kworker/u4:10/2932: 2 locks held by getty/5537: #0: ffff88802d3730a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217 4 locks held by kworker/0:5/5826: #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc900042a7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc900042a7d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88802f4f20e0 (&type->s_umount_key#25){++++}-{3:3}, at: flush_old_commits+0xcc/0x2f0 fs/reiserfs/super.c:97 #3: ffff888079862090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27 4 locks held by kworker/1:4/5831: #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #0: ffff888017871138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #1: ffffc90004317d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline] #1: ffffc90004317d00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711 #2: ffff88805e9e40e0 (&type->s_umount_key#25){++++}-{3:3}, at: flush_old_commits+0xcc/0x2f0 fs/reiserfs/super.c:97 #3: ffff88801f712090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x79/0xd0 fs/reiserfs/lock.c:27 3 locks held by syz.0.26/5967: 3 locks held by syz.0.26/5969: #0: ffff88807a46c418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff8880789d82f0 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff8880789d82f0 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline] #1: ffff8880789d82f0 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794 #2: ffff88807b0e4090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock_nested+0x60/0xd0 fs/reiserfs/lock.c:78 3 locks held by syz.1.30/6013: 3 locks held by syz.2.40/6074: 4 locks held by syz.2.40/6076: #0: ffff88805f82e418 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412 #1: ffff88805e570990 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline] #1: ffff88805e570990 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: open_last_lookups fs/namei.c:3561 [inline] #1: ffff88805e570990 (&type->i_mutex_dir_key#8){+.+.}-{3:3}, at: path_openat+0x7c6/0x3190 fs/namei.c:3794 #2: ffffc900047310f0 (&journal->j_mutex){+.+.}-{3:3}, at: reiserfs_mutex_lock_safe fs/reiserfs/reiserfs.h:813 [inline] #2: ffffc900047310f0 (&journal->j_mutex){+.+.}-{3:3}, at: lock_journal fs/reiserfs/journal.c:534 [inline] #2: ffffc900047310f0 (&journal->j_mutex){+.+.}-{3:3}, at: do_journal_end+0x3b0/0x4860 fs/reiserfs/journal.c:4032 #3: ffff88801b7f6090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock_nested+0x60/0xd0 fs/reiserfs/lock.c:78 3 locks held by syz.3.55/6162: 3 locks held by syz.4.76/6279: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 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+0x16c/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xf41/0xf80 kernel/hung_task.c:379 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6074 Comm: syz.2.40 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:193 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:216 Code: b0 0a 7e 7e 65 8b 15 b1 0a 7e 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 <83> fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc RSP: 0018:ffffc9000468eb58 EFLAGS: 00000246 RAX: ffffffff82227d64 RBX: 0000000000000000 RCX: ffff8880248b0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000010 RBP: ffffc9000468eca0 R08: 0000000000000000 R09: 00000000ffffffff R10: 0000000000000070 R11: 0000000000000000 R12: ffff88802c46c030 R13: dffffc0000000000 R14: 0000000000000001 R15: 1ffff1100588d806 FS: 00007f337f9736c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fc2800f98 CR3: 000000007f663000 CR4: 00000000003506e0 Call Trace: get_num_ver+0x5c4/0xfe0 fs/reiserfs/fix_node.c:515 ip_check_balance fs/reiserfs/fix_node.c:1523 [inline] check_balance fs/reiserfs/fix_node.c:2083 [inline] fix_nodes+0x2854/0x82e0 fs/reiserfs/fix_node.c:2636 reiserfs_paste_into_item+0x5ce/0x7f0 fs/reiserfs/stree.c:2128 reiserfs_get_block+0x1bd3/0x3ed0 fs/reiserfs/inode.c:1069 __block_write_begin_int+0x566/0x1ad0 fs/buffer.c:2124 reiserfs_write_begin+0x20a/0x4c0 fs/reiserfs/inode.c:2771 generic_perform_write+0x2fb/0x5b0 mm/filemap.c:4031 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4152 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x43b/0x940 fs/read_write.c:584 ksys_pwrite64 fs/read_write.c:699 [inline] __do_sys_pwrite64 fs/read_write.c:709 [inline] __se_sys_pwrite64 fs/read_write.c:706 [inline] __x64_sys_pwrite64+0x195/0x220 fs/read_write.c:706 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f337eb8f749 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:00007f337f973038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f337ede5fa0 RCX: 00007f337eb8f749 RDX: 0000000000000001 RSI: 000020000001f900 RDI: 0000000000000005 RBP: 00007f337ec13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000008000c63 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f337ede6038 R14: 00007f337ede5fa0 R15: 00007ffd30cd22e8