INFO: task syz-executor239:4993 blocked for more than 143 seconds. Not tainted 6.4.0-rc1-syzkaller-00138-gd4d58949a6ea #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor239 state:D stack:24992 pid:4993 ppid:4990 flags:0x00004002 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 ptrace_notify+0x2cd/0x380 kernel/signal.c:2369 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:252 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:279 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:284 [inline] syscall_exit_to_user_mode+0x157/0x280 kernel/entry/common.c:297 do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fcc92f55ef7 RSP: 002b:00007ffe9dbc3d28 EFLAGS: 00000206 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 000000000000d900 RCX: 00007fcc92f55ef7 RDX: 00007ffe9dbc3de7 RSI: 000000000000000a RDI: 00007ffe9dbc3de0 RBP: 00007ffe9dbc3de0 R08: 00000000ffffffff R09: 00007ffe9dbc3bc0 R10: 0000555557232633 R11: 0000000000000206 R12: 00007ffe9dbc4e50 R13: 00005555572325f0 R14: 00007ffe9dbc3d50 R15: 0000000000000001 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cf27670 (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: ffffffff8cf27a30 (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: ffffffff8cf274a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 3 locks held by kworker/1:1H/52: #0: ffff888140053938 ((wq_completion)kblockd){+.+.}-{0:0}, 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+0x441/0x770 kernel/sched/psi.c:996 #2: ffffffff8cf274a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x40 include/linux/rcupdate.h:326 5 locks held by kworker/u4:5/1002: 2 locks held by getty/4747: #0: ffff888028d43098 (&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-executor239/4993: #0: ffff88807c5a20e0 (&type->s_umount_key#30){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:361 #1: ffff888140b567d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140b567d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x278/0xab0 fs/fs-writeback.c:2728 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc1-syzkaller-00138-gd4d58949a6ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted 6.4.0-rc1-syzkaller-00138-gd4d58949a6ea #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/28/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:19 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:67 [inline] RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:103 [inline] RIP: 0010:lock_release+0x140/0x9d0 kernel/locking/lockdep.c:5707 Code: 42 0f b6 04 38 84 c0 0f 85 c3 05 00 00 83 3b 00 0f 85 ff 04 00 00 4c 8d b4 24 b0 00 00 00 4c 89 f3 48 c1 eb 03 42 80 3c 3b 00 <74> 08 4c 89 f7 e8 a6 11 78 00 4c 89 6c 24 50 48 c7 84 24 b0 00 00 RSP: 0018:ffffc90000117700 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 1ffff92000022ef6 RCX: ffffffff816b2380 RDX: 0000000000000000 RSI: ffffffff8b3840e0 RDI: ffffffff8b3840a0 RBP: ffffc90000117828 R08: dffffc0000000000 R09: fffffbfff1cab846 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000022eec R13: ffffffff815efbdb R14: ffffc900001177b0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feb454c8580 CR3: 000000000cd30000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: do_write_seqcount_end include/linux/seqlock.h:561 [inline] psi_account_irqtime+0x371/0x5e0 kernel/sched/psi.c:1026 update_rq_clock_task kernel/sched/core.c:725 [inline] update_rq_clock+0x22b/0x890 kernel/sched/core.c:769 __schedule+0x442/0x4900 kernel/sched/core.c:6591 schedule+0xc3/0x180 kernel/sched/core.c:6745 toggle_allocation_gate+0x16a/0x250 mm/kfence/core.c:833 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