INFO: task syz-executor.2:5032 blocked for more than 143 seconds. Not tainted 6.4.0-rc4-syzkaller-00276-ge5282a7d8f6b #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.2 state:D stack:20728 pid:5032 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0x187b/0x4900 kernel/sched/core.c:6669 schedule+0xc3/0x180 kernel/sched/core.c:6745 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x297/0xab0 fs/fs-writeback.c:2730 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x6f/0x340 fs/super.c:473 kill_block_super+0x84/0xf0 fs/super.c:1407 deactivate_locked_super+0xa4/0x110 fs/super.c:331 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1177 task_work_run+0x24a/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xd9/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x64/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fe51fe8d5d7 RSP: 002b:00007fff14804cc8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007fe51fe8d5d7 RDX: 00007fff14804d9a RSI: 000000000000000a RDI: 00007fff14804d90 RBP: 00007fff14804d90 R08: 00000000ffffffff R09: 00007fff14804b60 R10: 000055555606a893 R11: 0000000000000246 R12: 00007fe51fee6cdc R13: 00007fff14805e50 R14: 000055555606a810 R15: 00007fff14805e90 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf276f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cf27ab0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8cf27520 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:5/1014: #0: ffff88801425f138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc90004f47d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 1 lock held by syslogd/4428: #0: ffff8880b993c1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 2 locks held by getty/4752: #0: ffff888028b85098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015902f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor.2/5032: #0: ffff8880273760e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff88801eedc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff88801eedc7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728 5 locks held by kworker/0:7/5128: #0: ffff8880b983c1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b98287c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a7/0x770 kernel/sched/psi.c:984 #2: ffff8880b98295d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 #3: ffffffff91e20c98 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x16f/0x8b0 lib/debugobjects.c:708 #4: ffffffff91e1f6f0 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:1011 [inline] #4: ffffffff91e1f6f0 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0xd6/0x650 lib/debugobjects.c:1054 2 locks held by kworker/u4:8/7048: #0: ffff8880b983c1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b98287c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x441/0x770 kernel/sched/psi.c:996 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc4-syzkaller-00276-ge5282a7d8f6b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x187/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xec2/0xf00 kernel/hung_task.c:379 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: kworker/u4:2 Not tainted 6.4.0-rc4-syzkaller-00276-ge5282a7d8f6b #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4606 [inline] RIP: 0010:__lock_acquire+0xd8d/0x2070 kernel/locking/lockdep.c:5072 Code: 84 c0 0f 85 42 0c 00 00 48 8b 04 24 8b 18 48 85 db 74 59 83 fb 31 0f 83 2f 11 00 00 48 8d 04 9b 48 8b 4c 24 08 48 8d 5c c1 f8 <48> 89 d8 48 c1 e8 03 0f b6 04 38 84 c0 0f 85 73 0d 00 00 8b 1b 48 RSP: 0018:ffffc90000a5f988 EFLAGS: 00000087 RAX: 000000000000000a RBX: ffff88801766a8d0 RCX: ffff88801766a888 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffff88801766a878 R08: dffffc0000000000 R09: fffffbfff206524d R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888017669dc0 R13: 1ffff11002ecd50d R14: 0000000000000000 R15: cb55c700f932b2b5 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd9d502bb50 CR3: 000000002a1ea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5705 rcu_lock_acquire+0x2e/0x40 include/linux/rcupdate.h:327 rcu_read_lock include/linux/rcupdate.h:773 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xc5/0x5c0 net/batman-adv/network-coding.c:719 process_one_work+0x8a0/0x10e0 kernel/workqueue.c:2405 worker_thread+0xa63/0x1210 kernel/workqueue.c:2552 kthread+0x2b8/0x350 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308