INFO: task kworker/u4:5:3721 blocked for more than 143 seconds. Not tainted 6.1.101-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:5 state:D stack:20544 pid:3721 ppid:2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0x6b9/0xd80 kernel/locking/mutex.c:747 exfat_write_inode+0x65/0x110 fs/exfat/inode.c:94 write_inode fs/fs-writeback.c:1460 [inline] __writeback_single_inode+0x67d/0x11e0 fs/fs-writeback.c:1677 writeback_sb_inodes+0xc2b/0x1b20 fs/fs-writeback.c:1903 __writeback_inodes_wb+0x114/0x400 fs/fs-writeback.c:1974 wb_writeback+0x4b1/0xe10 fs/fs-writeback.c:2079 wb_check_old_data_flush fs/fs-writeback.c:2179 [inline] wb_do_writeback fs/fs-writeback.c:2232 [inline] wb_workfn+0xbec/0x1020 fs/fs-writeback.c:2260 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32af10 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b710 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/27: #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32ad40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494 2 locks held by getty/3396: #0: ffff88802927c098 (&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:2198 3 locks held by kworker/u5:6/3658: #0: ffff888023d59138 ((wq_completion)hci0){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000446fd20 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffff888060de50b8 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1dc/0x400 net/bluetooth/hci_sync.c:321 4 locks held by kworker/u4:5/3721: #0: ffff888014a75938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc90004af7d20 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #2: ffff88807caf40e0 (&type->s_umount_key#80){++++}-{3:3}, at: trylock_super+0x1b/0xf0 fs/super.c:415 #3: ffff8880535e20e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_write_inode+0x65/0x110 fs/exfat/inode.c:94 3 locks held by syz-executor/4454: 2 locks held by kworker/1:15/5285: #0: ffff888012872138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 #1: ffffc9000372fd20 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a9/0x11d0 kernel/workqueue.c:2267 2 locks held by syz.1.1033/7895: #0: ffff88807caf40e0 (&type->s_umount_key#80){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744 #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 2 locks held by syz.3.1054/7971: #0: ffff88807caf40e0 (&type->s_umount_key#80){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744 #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 2 locks held by syz-executor/8111: #0: ffff8880567500e0 (&type->s_umount_key#91){+.+.}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffffffff8d330338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] #1: ffffffff8d330338 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x4f0/0x930 kernel/rcu/tree_exp.h:962 2 locks held by syz.2.1114/8139: #0: ffff88807caf40e0 (&type->s_umount_key#80){++++}-{3:3}, at: iterate_supers+0xac/0x1e0 fs/super.c:744 #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888142f5a7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 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+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4454 Comm: syz-executor Not tainted 6.1.101-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:check_preemption_disabled+0x5c/0x110 lib/smp_processor_id.c:19 Code: 25 28 00 00 00 48 3b 44 24 08 0f 85 c7 00 00 00 89 d8 48 83 c4 10 5b 41 5c 41 5e 41 5f c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 74 c9 49 89 f6 49 89 ff 65 4c 8b 25 2d 7c 5d RSP: 0018:ffffc900048cf488 EFLAGS: 00000046 RAX: 0000000080000000 RBX: 0000000000000001 RCX: ffff88805f43d940 RDX: 0000000000000000 RSI: ffffffff8b1a14e0 RDI: ffffffff8b5d5b60 RBP: ffffc900048cf600 R08: ffffffff820138cf R09: ffffffff825b8793 R10: 0000000000000003 R11: ffff88805f43d940 R12: 0000000000000000 R13: ffff8880585c19f8 R14: 0000000000000200 R15: 0000000000036940 FS: 0000555555d44500(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f32aa4d2178 CR3: 000000006108f000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lookup_bh_lru fs/buffer.c:1280 [inline] __find_get_block+0x677/0x1120 fs/buffer.c:1303 __getblk_gfp+0x2d/0xa20 fs/buffer.c:1329 __bread_gfp+0x2a/0x370 fs/buffer.c:1367 sb_bread include/linux/buffer_head.h:338 [inline] exfat_get_dentry+0x64d/0x8f0 fs/exfat/dir.c:731 exfat_readdir fs/exfat/dir.c:121 [inline] exfat_iterate+0xb4f/0x3280 fs/exfat/dir.c:257 iterate_dir+0x224/0x560 __do_sys_getdents64 fs/readdir.c:369 [inline] __se_sys_getdents64+0x209/0x4f0 fs/readdir.c:354 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa16d9a9333 Code: c1 66 0f 1f 44 00 00 48 83 c4 08 48 89 ef 5b 5d e9 02 45 f8 ff 66 90 b8 ff ff ff 7f 48 39 c2 48 0f 47 d0 b8 d9 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 05 c3 0f 1f 40 00 48 c7 c2 a8 ff ff ff f7 d8 RSP: 002b:00007ffc8a3de148 EFLAGS: 00000293 ORIG_RAX: 00000000000000d9 RAX: ffffffffffffffda RBX: 0000555555d5f600 RCX: 00007fa16d9a9333 RDX: 0000000000008000 RSI: 0000555555d5f600 RDI: 0000000000000005 RBP: 0000555555d5f5d4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000001000 R11: 0000000000000293 R12: ffffffffffffffa8 R13: 0000000000000010 R14: 0000555555d5f5d0 R15: 00007ffc8a3e03f0