INFO: task syz-executor.0:5090 blocked for more than 143 seconds. Not tainted 6.7.0-rc6-syzkaller-00078-ga4aebe936554 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:20016 pid:5090 tgid:5090 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0x1961/0x4ab0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0x149/0x260 kernel/sched/core.c:6778 wb_wait_for_completion+0x166/0x290 fs/fs-writeback.c:192 sync_inodes_sb+0x293/0xb20 fs/fs-writeback.c:2758 sync_filesystem+0x16f/0x220 fs/sync.c:64 generic_shutdown_super+0x72/0x2c0 fs/super.c:669 kill_block_super+0x44/0x90 fs/super.c:1667 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7330 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:171 exit_to_user_mode_prepare+0xb1/0x150 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline] syscall_exit_to_user_mode+0x69/0x2a0 kernel/entry/common.c:296 do_syscall_64+0x52/0x110 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f8110a7e017 RSP: 002b:00007fffd64157d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8110a7e017 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007fffd6415890 RBP: 00007fffd6415890 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffd6416950 R13: 00007f8110ac83b9 R14: 0000000000061e6a R15: 000000000000000a Showing all locks held in the system: 1 lock held by khungtaskd/29: #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:301 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:747 [inline] #0: ffffffff8d92dae0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6614 3 locks held by kworker/u4:3/48: 3 locks held by kworker/u4:5/152: 2 locks held by getty/4810: #0: ffff88802ad220a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc900015c02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6b4/0x1e10 drivers/tty/n_tty.c:2201 2 locks held by syz-executor.0/5090: #0: ffff8880261c40e0 (&type->s_umount_key#30){++++}-{3:3}, at: __super_lock fs/super.c:56 [inline] #0: ffff8880261c40e0 (&type->s_umount_key#30){++++}-{3:3}, at: __super_lock_excl fs/super.c:71 [inline] #0: ffff8880261c40e0 (&type->s_umount_key#30){++++}-{3:3}, at: deactivate_super+0xad/0xf0 fs/super.c:516 #1: ffff88801cca47d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:364 [inline] #1: ffff88801cca47d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x274/0xb20 fs/fs-writeback.c:2756 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 29 Comm: khungtaskd Not tainted 6.7.0-rc6-syzkaller-00078-ga4aebe936554 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106 nmi_cpu_backtrace+0x498/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x310 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xfaf/0xff0 kernel/hung_task.c:379 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 152 Comm: kworker/u4:5 Not tainted 6.7.0-rc6-syzkaller-00078-ga4aebe936554 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:PageTail include/linux/page-flags.h:286 [inline] RIP: 0010:folio_flags include/linux/page-flags.h:313 [inline] RIP: 0010:folio_test_head include/linux/page-flags.h:790 [inline] RIP: 0010:folio_test_large include/linux/page-flags.h:811 [inline] RIP: 0010:folio_nr_pages include/linux/mm.h:2048 [inline] RIP: 0010:filemap_get_folios_tag+0x641/0x900 mm/filemap.c:2219 Code: 01 48 8b 5c 24 38 0f 85 b2 00 00 00 e8 e8 bc cc ff e9 cc 00 00 00 e8 de bc cc ff 48 8b 5c 24 38 e9 bd 00 00 00 49 8d 5c 24 08 <48> 89 d8 48 c1 e8 03 49 bf 00 00 00 00 00 fc ff df 42 80 3c 38 00 RSP: 0018:ffffc90002edeb60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0000ecc648 RCX: dffffc0000000000 RDX: ffff888016b50000 RSI: 000000000000000f RDI: 000000000000000f RBP: ffffc90002edec90 R08: ffffffff81c1abbe R09: 1ffffd40001d98ce R10: dffffc0000000000 R11: fffff940001d98cf R12: ffffea0000ecc640 R13: ffffc90002eded60 R14: 0000000000000008 R15: 000000000000000f FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005573cf05c110 CR3: 000000000d731000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mpage_release_unused_pages+0x35a/0xe70 fs/ext4/inode.c:1574 ext4_do_writepages+0x2d72/0x3ca0 fs/ext4/inode.c:2703 ext4_writepages+0x203/0x3e0 fs/ext4/inode.c:2774 do_writepages+0x3a6/0x670 mm/page-writeback.c:2553 __writeback_single_inode+0x155/0xfc0 fs/fs-writeback.c:1625 writeback_sb_inodes+0x8e3/0x1220 fs/fs-writeback.c:1916 wb_writeback+0x44d/0xc70 fs/fs-writeback.c:2092 wb_do_writeback fs/fs-writeback.c:2239 [inline] wb_workfn+0x400/0xfb0 fs/fs-writeback.c:2279 process_one_work kernel/workqueue.c:2627 [inline] process_scheduled_works+0x90f/0x1420 kernel/workqueue.c:2700 worker_thread+0xa5f/0x1000 kernel/workqueue.c:2781 kthread+0x2d3/0x370 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242