INFO: task kworker/u4:4:3680 blocked for more than 143 seconds. Not tainted 6.1.27-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:4 state:D stack:25464 pid:3680 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x132c/0x4330 kernel/sched/core.c:6554 schedule+0xbf/0x180 kernel/sched/core.c:6630 rwsem_down_write_slowpath+0xe93/0x14a0 kernel/locking/rwsem.c:1189 f2fs_down_write fs/f2fs/f2fs.h:2207 [inline] f2fs_balance_fs+0x4fb/0x6c0 fs/f2fs/segment.c:418 f2fs_write_inode+0x4c3/0x540 fs/f2fs/inode.c:757 write_inode fs/fs-writeback.c:1443 [inline] __writeback_single_inode+0x67d/0x11e0 fs/fs-writeback.c:1655 writeback_sb_inodes+0xc21/0x1ac0 fs/fs-writeback.c:1881 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1952 wb_writeback+0x4b1/0xe10 fs/fs-writeback.c:2057 wb_check_old_data_flush fs/fs-writeback.c:2157 [inline] wb_do_writeback fs/fs-writeback.c:2210 [inline] wb_workfn+0xbec/0x1020 fs/fs-writeback.c:2238 process_one_work+0x8aa/0x11f0 kernel/workqueue.c:2289 worker_thread+0xa5f/0x1210 kernel/workqueue.c:2436 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cf273f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cf27bf0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xd20 kernel/rcu/tasks.h:510 1 lock held by khungtaskd/28: #0: ffffffff8cf27220 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 1 lock held by hwrng/769: #0: ffffffff8d6731e8 (reading_mutex){+.+.}-{3:3}, at: hwrng_fillfn+0xe2/0x3b0 drivers/char/hw_random/core.c:506 1 lock held by udevd/3000: 2 locks held by getty/3301: #0: ffff88814bc15098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900031262f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2177 5 locks held by syz-executor.5/3586: 2 locks held by kworker/u4:19/5532: #0: ffff888012469138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc9001624fd20 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 3 locks held by kworker/u4:21/5536: 1 lock held by syz-executor.1/15722: #0: ffffffff8cf2c7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline] #0: ffffffff8cf2c7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x479/0x8a0 kernel/rcu/tree_exp.h:948 2 locks held by kworker/u4:5/28961: #0: ffff888012469138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc90005467d20 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 2 locks held by kworker/0:3/1610: #0: ffff888012466538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc9000a93fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 3 locks held by kworker/0:4/1667: #0: ffff888012464d38 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc9000b587d20 ((work_completion)(&pwq->unbound_release_work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 #2: ffffffff8cf2c7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:292 [inline] #2: ffffffff8cf2c7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3b0/0x8a0 kernel/rcu/tree_exp.h:948 3 locks held by syz-executor.3/3354: 6 locks held by kworker/1:1/3679: #0: ffff8880172d8538 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc9000560fd20 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 #2: ffff888145b68190 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:836 [inline] #2: ffff888145b68190 (&dev->mutex){....}-{3:3}, at: hub_event+0x20e/0x57b0 drivers/usb/core/hub.c:5683 #3: ffff888145b6b4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: usb_lock_port drivers/usb/core/hub.c:3105 [inline] #3: ffff888145b6b4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect drivers/usb/core/hub.c:5251 [inline] #3: ffff888145b6b4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_port_connect_change drivers/usb/core/hub.c:5499 [inline] #3: ffff888145b6b4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: port_event drivers/usb/core/hub.c:5655 [inline] #3: ffff888145b6b4f8 (&port_dev->status_lock){+.+.}-{3:3}, at: hub_event+0x2278/0x57b0 drivers/usb/core/hub.c:5737 #4: ffff8880b9927788 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x43d/0x770 kernel/sched/psi.c:952 #5: ffffffff91cdce38 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x97/0x690 lib/debugobjects.c:665 4 locks held by kworker/u4:4/3680: #0: ffff888142a86938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x77a/0x11f0 #1: ffffc9000561fd20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7bd/0x11f0 kernel/workqueue.c:2264 #2: ffff8880804120e0 (&type->s_umount_key#79){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:415 #3: ffff88808ce39140 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2207 [inline] #3: ffff88808ce39140 (&sbi->gc_lock){+.+.}-{3:3}, at: f2fs_balance_fs+0x4fb/0x6c0 fs/f2fs/segment.c:418 2 locks held by syz-executor.0/6287: 1 lock held by syz-executor.2/6407: #0: ffffffff8cf2c6c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x5f0 kernel/rcu/tree.c:3953 2 locks held by syz-executor.0/6440: 2 locks held by syz-executor.0/6445: 1 lock held by syz-executor.3/6447: #0: ffffc9000aed90a8 (&kvm->slots_lock){+.+.}-{3:3}, at: kvm_free_pit+0x52/0x210 arch/x86/kvm/i8254.c:741 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.27-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b0/0x3f0 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+0xf18/0xf60 kernel/hung_task.c:377 kthread+0x26e/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6440 Comm: syz-executor.0 Not tainted 6.1.27-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023 RIP: 0010:kasan_check_range+0x1/0x290 mm/kasan/generic.c:188 Code: 01 c6 48 89 c7 e8 1f 2c a2 08 31 c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc cc cc cc cc 55 <41> 57 41 56 53 b0 01 48 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5 RSP: 0018:ffffc9000a9274d0 EFLAGS: 00000286 RAX: 0000000000000004 RBX: 0000000000000000 RCX: ffffffff81691cec RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff888074becd28 RBP: ffffc9000a9275b0 R08: dffffc0000000000 R09: ffffed100e97d9a6 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888074becd28 R13: 1ffff92001524ea8 R14: ffff888037fb0000 R15: ffff888037fb0000 FS: 00007f46467dd700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020395030 CR3: 00000000938f9000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:102 [inline] atomic_long_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1779 [inline] __mutex_trylock_common+0x16c/0x2e0 kernel/locking/mutex.c:129 __mutex_trylock kernel/locking/mutex.c:152 [inline] __mutex_lock_common+0x1ef/0x2520 kernel/locking/mutex.c:606 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 __unix_dgram_recvmsg+0x24d/0x1260 net/unix/af_unix.c:2448 ____sys_recvmsg+0x285/0x530 ___sys_recvmsg net/socket.c:2743 [inline] do_recvmmsg+0x46d/0xad0 net/socket.c:2837 __sys_recvmmsg net/socket.c:2916 [inline] __do_sys_recvmmsg net/socket.c:2939 [inline] __se_sys_recvmmsg net/socket.c:2932 [inline] __x64_sys_recvmmsg+0x195/0x240 net/socket.c:2932 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4647c8c169 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f46467dd168 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f4647dac050 RCX: 00007f4647c8c169 RDX: 0000000000010106 RSI: 00000000200000c0 RDI: 0000000000000005 RBP: 00007f4647ce7ca1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe88caf26f R14: 00007f46467dd300 R15: 0000000000022000