INFO: task kworker/0:6:4372 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/0:6 state:D stack:23008 pid:4372 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 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 1 lock held by khungtaskd/27: #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 3 locks held by kworker/1:1/41: #0: ffff88814cab9938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b27d00 ((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 1 lock held by dhcpcd/3932: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x288/0x1af0 net/ipv4/devinet.c:1080 2 locks held by getty/4026: #0: ffff88814ce22098 (&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/1:6/4314: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900043c7d00 (deferred_process_work ){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104 3 locks held by kworker/u4:6/4360: #0: ffff888017479138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900046cfd00 ((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 4 locks held by kworker/0:6/4372: #0: ffff888017471138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900046bfd00 ((work_completion)(&(&sbi->old_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807d2520e0 (&type->s_umount_key#92 ){++++}-{3:3}, at: flush_old_commits+0xc8/0x2f0 fs/reiserfs/super.c:97 #3: ffff888028cb9090 ( &sbi->lock ){+.+.}-{3:3}, at: reiserfs_write_lock+0x75/0xd0 fs/reiserfs/lock.c:27 5 locks held by kworker/u4:11/4453: #0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000493fd00 (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: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489 #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 2 locks held by kworker/1:10/4460: #0: ffff888017472138 ( (wq_completion)rcu_gp ){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900049efd00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 3 locks held by kworker/0:9/4546: #0: ffff88814cab9938 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc9000481fd00 ((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 3 locks held by kworker/u4:14/4623: 1 lock held by syz.9.153/5440: 3 locks held by syz.5.325/6467: 4 locks held by syz-executor/6873: #0: ffff88807e014460 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff88802f8e7c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff88814536f1d8 (kn->active#54){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] #2: ffff88814536f1d8 (kn->active#54){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: new_device_store+0x129/0x670 drivers/net/netdevsim/bus.c:160 7 locks held by syz-executor/6972: #0: ffff88807e014460 ( sb_writers#8){.+.+}-{0:0} , at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff888057b77c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff88814536f2c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] ffff88814536f2c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d44d168 ( nsim_bus_dev_list_lock ){+.+.}-{3:3} , at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209 #4: ffff88807935a0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:840 [inline] #4: ffff88807935a0e8 (&dev->mutex){....}-{3:3}, at: __device_driver_lock drivers/base/dd.c:1080 [inline] #4: ffff88807935a0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0xb2/0x850 drivers/base/dd.c:1283 #5: ffff88807935f2f8 (&devlink->lock_key #16 ){+.+.}-{3:3} , at: nsim_drv_remove+0x54/0x160 drivers/net/netdevsim/dev.c:1677 #6: ffffffff8db3b3a8 ( rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x3b/0x150 drivers/net/netdevsim/netdev.c:381 1 lock held by syz-executor/6974: #0: ffffffff8db3b3a8 (rtnl_mutex ){+.+.}-{3:3} , at: rtnl_lock net/core/rtnetlink.c:74 [inline] , at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 4 locks held by syz-executor/6984: #0: ffff88807e014460 ( sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x256/0x960 fs/read_write.c:580 #1: ffff88801d318c88 (&of->mutex){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x1e3/0x520 fs/kernfs/file.c:343 #2: ffff88814536f2c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline] ffff88814536f2c0 (kn->active#53){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x236/0x520 fs/kernfs/file.c:344 #3: ffffffff8d44d168 (nsim_bus_dev_list_lock){+.+.}-{3:3}, at: del_device_store+0xce/0x360 drivers/net/netdevsim/bus.c:209 1 lock held by syz-executor/6986: #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 1 lock held by syz-executor/7276: #0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 1 lock held by syz-executor/7281: #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 1 lock held by syz-executor/7286: #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 1 lock held by syz-executor/7288: #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 1 lock held by syz-executor/7290: #0: ffffffff8db3b3a8 ( rtnl_mutex ){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] ){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147 ============================================= NMI backtrace for cpu 1 CPU: 1 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6467 Comm: syz.5.325 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_static_branch include/trace/events/preemptirq.h:40 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:trace_irq_enable_rcuidle+0x7/0x140 include/trace/events/preemptirq.h:40 Code: 31 f6 e8 1c 00 00 00 65 c7 05 29 fa 7b 7e 00 00 00 00 e8 dc 90 db ff 48 8b 3c 24 e9 93 30 89 08 0f 1f 00 55 41 57 41 56 41 55 <41> 54 53 66 90 5b 41 5c 41 5d 41 5e 41 5f 5d c3 49 89 fe 48 89 f3 RSP: 0018:ffffc90003426c08 EFLAGS: 00000046 RAX: 0000000080000001 RBX: 0000000000000000 RCX: 542a95c022b5ae00 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffffffff8a200d46 RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed102802f381 R10: ffffed102802f381 R11: 1ffff1102802f380 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f674465c6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001000 CR3: 000000007413b000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:1948 [inline] RIP: 0010:vprintk_emit+0x461/0x680 kernel/printk/printk.c:2302 Code: 85 8f 01 00 00 e8 af b9 1a 00 41 89 df 4d 85 f6 48 8b 1c 24 75 07 e8 9e b9 1a 00 eb 06 e8 97 b9 1a 00 fb 48 c7 c7 c0 f3 91 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 37 db RSP: 0018:ffffc90003426ce0 EFLAGS: 00000246 RAX: ffffffff81662639 RBX: ffffffff816624e5 RCX: 0000000000080000 RDX: ffffc90005bda000 RSI: 000000000007ffff RDI: ffffffff8c91f3c0 RBP: ffffc90003426dd0 R08: dffffc0000000000 R09: fffffbfff2119064 R10: fffffbfff2119064 R11: 1ffffffff2119063 R12: dffffc0000000000 R13: 1ffff92000684da0 R14: 0000000000000200 R15: 0000000000000086 _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 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_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+0x191/0x220 fs/read_write.c:706 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: 0033:0x7f674378f749 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:00007f674465c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f67439e5fa0 RCX: 00007f674378f749 RDX: 000000000000fdef RSI: 0000200000000140 RDI: 000000000000000a RBP: 00007f6743813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000e7c R11: 0000000000000246 R12: 0000000000000000 R13: 00007f67439e6038 R14: 00007f67439e5fa0 R15: 00007fffa4b94b98