INFO: task syz-executor.0:5069 blocked for more than 143 seconds. Not tainted 6.4.0-rc7-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:23928 pid:5069 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5343 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6669 schedule+0xde/0x1a0 kernel/sched/core.c:6745 wb_wait_for_completion+0x182/0x240 fs/fs-writeback.c:192 sync_inodes_sb+0x1aa/0xa60 fs/fs-writeback.c:2730 sync_filesystem.part.0+0xe6/0x1d0 fs/sync.c:64 sync_filesystem+0x8f/0xc0 fs/sync.c:43 generic_shutdown_super+0x74/0x480 fs/super.c:473 kill_block_super+0xa1/0x100 fs/super.c:1407 deactivate_locked_super+0x98/0x160 fs/super.c:331 deactivate_super+0xb1/0xd0 fs/super.c:362 cleanup_mnt+0x2ae/0x3d0 fs/namespace.c:1177 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7ff5c1e8d7f7 RSP: 002b:00007ffc7d6ee9d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007ff5c1e8d7f7 RDX: 00007ffc7d6eeaab RSI: 000000000000000a RDI: 00007ffc7d6eeaa0 RBP: 00007ffc7d6eeaa0 R08: 00000000ffffffff R09: 00007ffc7d6ee870 R10: 0000555556fe88e3 R11: 0000000000000246 R12: 00007ff5c1ed643b R13: 00007ffc7d6efb60 R14: 0000555556fe8810 R15: 00007ffc7d6efba0 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c7984b0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c7981b0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:518 1 lock held by khungtaskd/28: #0: ffffffff8c7990c0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6559 2 locks held by getty/4753: #0: ffff88802cad2098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015b02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 2 locks held by syz-executor.0/5069: #0: ffff88807b7a60e0 (&type->s_umount_key#48){+.+.}-{3:3}, at: deactivate_super+0xa9/0xd0 fs/super.c:361 #1: ffff888140ff87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff888140ff87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x190/0xa60 fs/fs-writeback.c:2728 2 locks held by kworker/u4:3/5167: #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1324 [inline] #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:643 [inline] #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:670 [inline] #0: ffff88814565b138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x883/0x15e0 kernel/workqueue.c:2376 #1: ffffc900043efdb0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x8b7/0x15e0 kernel/workqueue.c:2380 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.4.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 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+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 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: 5122 Comm: kworker/u4:0 Not tainted 6.4.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:lookup_chain_cache kernel/locking/lockdep.c:3740 [inline] RIP: 0010:lookup_chain_cache_add kernel/locking/lockdep.c:3760 [inline] RIP: 0010:validate_chain kernel/locking/lockdep.c:3815 [inline] RIP: 0010:__lock_acquire+0x19d9/0x5f30 kernel/locking/lockdep.c:5088 Code: 91 0f 84 c2 03 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 0f 85 53 3d 00 00 4a 8b 1c e5 60 3c 41 91 <48> 85 db 74 63 48 83 eb 08 74 5d 48 ba 00 00 00 00 00 fc ff df 4c RSP: 0018:ffffc9000428f7b0 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffffffff903ef328 RCX: ffffffff81659797 RDX: 1ffffffff2285431 RSI: 0000000000000008 RDI: ffffffff9152bd00 RBP: ffff8880688d3b80 R08: 0000000000000000 R09: ffffffff9152bd07 R10: fffffbfff22a57a0 R11: 0000000000000001 R12: 0000000000002ca5 R13: ffffffff9142a188 R14: 0000000000000000 R15: ffff8880688d46e8 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbc76707000 CR3: 000000000c571000 CR4: 0000000000350ee0 Call Trace: lock_acquire kernel/locking/lockdep.c:5705 [inline] lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670 __mutex_lock_common kernel/locking/mutex.c:603 [inline] __mutex_lock+0x12f/0x1350 kernel/locking/mutex.c:747 arch_jump_label_transform_queue+0x5c/0x100 arch/x86/kernel/jump_label.c:136 __jump_label_update+0x12e/0x410 kernel/jump_label.c:475 jump_label_update+0x32f/0x410 kernel/jump_label.c:829 static_key_disable_cpuslocked+0x156/0x1b0 kernel/jump_label.c:235 static_key_disable+0x1a/0x20 kernel/jump_label.c:243 toggle_allocation_gate mm/kfence/core.c:836 [inline] toggle_allocation_gate+0x143/0x230 mm/kfence/core.c:823 process_one_work+0x99a/0x15e0 kernel/workqueue.c:2405 worker_thread+0x67d/0x10c0 kernel/workqueue.c:2552 kthread+0x344/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308