INFO: task kworker/u4:8:3822 blocked for more than 143 seconds. Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:8 state:D stack:19872 pid: 3822 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:2) Call Trace: context_switch kernel/sched/core.c:5182 [inline] __schedule+0x91f/0xdf0 kernel/sched/core.c:6494 schedule+0xcb/0x190 kernel/sched/core.c:6570 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6629 __mutex_lock_common+0xe4f/0x26e0 kernel/locking/mutex.c:679 __mutex_lock kernel/locking/mutex.c:747 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799 exfat_write_inode+0x65/0x110 fs/exfat/inode.c:94 write_inode fs/fs-writeback.c:1440 [inline] __writeback_single_inode+0x4d6/0x670 fs/fs-writeback.c:1652 writeback_sb_inodes+0xb3b/0x18f0 fs/fs-writeback.c:1865 __writeback_inodes_wb+0x125/0x420 fs/fs-writeback.c:1936 wb_writeback+0x440/0x7b0 fs/fs-writeback.c:2041 wb_check_old_data_flush fs/fs-writeback.c:2141 [inline] wb_do_writeback fs/fs-writeback.c:2194 [inline] wb_workfn+0xa78/0xef0 fs/fs-writeback.c:2222 process_one_work+0x877/0xdb0 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8cb233f0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by rcu_tasks_trace/14: #0: ffffffff8cb23bf0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x30/0xd00 kernel/rcu/tasks.h:507 1 lock held by khungtaskd/29: #0: ffffffff8cb23220 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3289: #0: ffff88814b0e9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc90002d232f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x53b/0x1650 drivers/tty/n_tty.c:2177 2 locks held by kworker/u4:7/3821: #0: ffff8880b9a39c18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x25/0x110 kernel/sched/core.c:544 #1: ffff8880b9a27748 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x5b3/0x8a0 kernel/sched/psi.c:885 4 locks held by kworker/u4:8/3822: #0: ffff8881459f4938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7f2/0xdb0 #1: ffffc90004f2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x831/0xdb0 kernel/workqueue.c:2264 #2: ffff888017a980e0 (&type->s_umount_key#73){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:415 #3: ffff88807b70e0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x65/0x110 fs/exfat/inode.c:94 5 locks held by syz-executor.2/15519: 2 locks held by syz-executor.5/17242: #0: ffff888017a980e0 (&type->s_umount_key#73){++++}-{3:3}, at: iterate_supers+0xb0/0x1f0 fs/super.c:721 #1: ffff8881475e87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881475e87d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x264/0xaa0 fs/fs-writeback.c:2691 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 29 Comm: khungtaskd Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1b1/0x28e lib/dump_stack.c:106 nmi_cpu_backtrace+0x425/0x450 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x169/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xcd5/0xd20 kernel/hung_task.c:369 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 15519 Comm: syz-executor.2 Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022 RIP: 0010:mark_lock+0xe7/0x350 kernel/locking/lockdep.c:4610 Code: de e8 f7 0f 00 74 4a 31 db eb 0f 48 8d 04 5b 48 c1 e0 06 48 8d 98 40 df af 8f 48 83 c3 50 48 89 d8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 df e8 2f 60 72 00 41 bc 01 00 00 00 44 85 33 74 56 44 RSP: 0000:ffffc90015b670d8 EFLAGS: 00000046 RAX: 1ffffffff1f6e622 RBX: ffffffff8fb73110 RCX: ffffffff8168163a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8fe08178 RBP: 0000000000000002 R08: dffffc0000000000 R09: fffffbfff1fc1030 R10: fffffbfff1fc1030 R11: 1ffffffff1fc102f R12: ffff8880259d2890 R13: dffffc0000000000 R14: 0000000000000004 R15: ffff8880259d2870 FS: 00007f5fae716700(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0e9c417008 CR3: 000000007a6b9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mark_held_locks kernel/locking/lockdep.c:4234 [inline] __trace_hardirqs_on_caller kernel/locking/lockdep.c:4252 [inline] lockdep_hardirqs_on_prepare+0x260/0x790 kernel/locking/lockdep.c:4319 trace_hardirqs_on+0x34/0x40 kernel/trace/trace_preemptirq.c:49 lookup_bh_lru fs/buffer.c:1291 [inline] __find_get_block+0x28c/0x1110 fs/buffer.c:1303 __getblk_gfp+0x2d/0x290 fs/buffer.c:1329 __bread_gfp+0x28/0x320 fs/buffer.c:1378 sb_bread include/linux/buffer_head.h:339 [inline] __exfat_ent_get fs/exfat/fatent.c:48 [inline] exfat_ent_get+0x147/0x400 fs/exfat/fatent.c:97 __exfat_free_cluster+0x5a0/0x9c0 fs/exfat/fatent.c:200 exfat_free_cluster+0x73/0xc0 fs/exfat/fatent.c:232 __exfat_truncate+0x66d/0x980 fs/exfat/file.c:186 exfat_truncate+0x113/0x3d0 fs/exfat/file.c:210 exfat_setattr+0xaa3/0xde0 fs/exfat/file.c:313 notify_change+0xe38/0x10f0 fs/attr.c:420 do_truncate+0x1fb/0x2e0 fs/open.c:65 handle_truncate fs/namei.c:3216 [inline] do_open fs/namei.c:3561 [inline] path_openat+0x2770/0x2df0 fs/namei.c:3691 do_filp_open+0x264/0x4f0 fs/namei.c:3718 do_sys_openat2+0x124/0x4e0 fs/open.c:1313 do_sys_open fs/open.c:1329 [inline] __do_sys_openat fs/open.c:1345 [inline] __se_sys_openat fs/open.c:1340 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1340 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: 0033:0x7f5fad68a669 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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:00007f5fae716168 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f5fad7abf80 RCX: 00007f5fad68a669 RDX: 000000000000275a RSI: 0000000020000000 RDI: ffffffffffffff9c RBP: 00007f5fad6e5560 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc888728af R14: 00007f5fae716300 R15: 0000000000022000