INFO: task syz-executor.0:10562 blocked for more than 143 seconds. Not tainted 6.1.84-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20472 pid:10562 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 __writeback_inodes_sb_nr+0x2ce/0x370 fs/fs-writeback.c:2653 sync_filesystem+0xa0/0x220 fs/sync.c:54 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1459 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7c8427f197 RSP: 002b:00007ffc33546df8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f7c8427f197 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffc33546eb0 RBP: 00007ffc33546eb0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffc33547f70 R13: 00007f7c842c93b9 R14: 00000000000b255b R15: 0000000000000014 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d12ab50 (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: ffffffff8d12b350 (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/28: #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d12a980 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6494 2 locks held by getty/3298: #0: ffff88807f4a0098 (&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:2188 1 lock held by syz-executor.0/10562: #0: ffff888060c920e0 (&type->s_umount_key#79){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 3 locks held by kworker/u4:13/19182: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 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:307 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 19182 Comm: kworker/u4:13 Not tainted 6.1.84-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:check_preemption_disabled+0x2/0x110 lib/smp_processor_id.c:13 Code: 1c 8d 48 89 de e8 ce f6 d8 f9 e9 6d ff ff ff cc cc cc cc cc cc cc cc cc 48 c7 c7 c0 2c 3d 8b 48 c7 c6 00 2d 3d 8b eb 00 41 57 <41> 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 RSP: 0018:ffffc9000dc871f0 EFLAGS: 00000082 RAX: ffffffff8200fdac RBX: 0000000000001d65 RCX: ffff88807a2cd940 RDX: 0000000000000000 RSI: ffffffff8af9ee40 RDI: ffffffff8b3d2d20 RBP: ffffc9000dc87340 R08: ffffffff8200fd04 R09: fffff9400025a5ef R10: 0000000000000000 R11: dffffc0000000001 R12: fffffffffffffffe R13: ffff88807101c570 R14: 0000000000000520 R15: 0000000000036948 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c0006c3fc0 CR3: 000000000ce8e000 CR4: 00000000003506f0 Call Trace: lookup_bh_lru fs/buffer.c:1274 [inline] __find_get_block+0x1ac/0x1120 fs/buffer.c:1303 __getblk_slow fs/buffer.c:1034 [inline] __getblk_gfp+0x146/0xa20 fs/buffer.c:1333 udf_update_inode+0xf7/0x2c20 fs/udf/inode.c:1682 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 wb_writeback+0x49d/0xe10 fs/fs-writeback.c:2077 wb_do_writeback fs/fs-writeback.c:2220 [inline] wb_workfn+0x427/0x1020 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:307