INFO: task syz-executor.1:5033 blocked for more than 143 seconds. Not tainted 6.4.0-rc4-syzkaller-00265-g4ecd704a4c51 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.1 state:D stack:19224 pid:5033 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: 0033:0x7f944368d5d7 RSP: 002b:00007ffe76e4ffa8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f944368d5d7 RDX: 00007ffe76e5007a RSI: 000000000000000a RDI: 00007ffe76e50070 RBP: 00007ffe76e50070 R08: 00000000ffffffff R09: 00007ffe76e4fe40 R10: 000055555620a893 R11: 0000000000000246 R12: 00007f94436e6cdc R13: 00007ffe76e51130 R14: 000055555620a810 R15: 00007ffe76e51170 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 getty/4748: #0: ffff88814aeb3098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015802f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6ab/0x1db0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor.1/5033: #0: ffff88801835a0e0 (&type->s_umount_key#68){+.+.}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff888140bb87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140bb87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728 3 locks held by kworker/1:5/5082: #0: ffff8880b993c1d8 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffff8880b99287c8 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x3a7/0x770 kernel/sched/psi.c:984 #2: ffff8880b99295d8 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999 2 locks held by kworker/u4:6/5320: #0: ffff888012ed5938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77e/0x10e0 kernel/workqueue.c:2378 #1: ffffc900053bfd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7c8/0x10e0 kernel/workqueue.c:2380 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc4-syzkaller-00265-g4ecd704a4c51 #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: 1006 Comm: kworker/u4:5 Not tainted 6.4.0-rc4-syzkaller-00265-g4ecd704a4c51 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0x4c/0x2070 kernel/locking/lockdep.c:4953 Code: fe 65 4c 8b 3d 95 9d 98 7e 48 c7 c0 04 01 56 8e 48 c1 e8 03 48 be 00 00 00 00 00 fc ff df 0f b6 04 30 84 c0 0f 85 d8 16 00 00 <83> 3d b1 e6 ea 0c 00 0f 84 83 11 00 00 83 3d e0 31 74 0b 00 74 2b RSP: 0018:ffffc90004d8f988 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002 RDX: 0000000000000000 RSI: dffffc0000000000 RDI: ffffffff8cf27520 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000 R13: 0000000000000002 R14: ffffffff8cf27520 R15: ffff888020efbb80 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0008dc000 CR3: 000000007e433000 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