INFO: task syz-executor:4393 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:22080 pid:4393 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 wb_wait_for_completion+0x162/0x280 fs/fs-writeback.c:191 sync_inodes_sb+0x1b8/0x9e0 fs/fs-writeback.c:2750 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7c/0xe0 fs/super.c:1470 deactivate_locked_super+0x93/0xf0 fs/super.c:332 cleanup_mnt+0x463/0x4f0 fs/namespace.c:1191 task_work_run+0x1ca/0x250 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff0ced90a77 RSP: 002b:00007fffbe497f78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff0cee13d7d RCX: 00007ff0ced90a77 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007fffbe498030 RBP: 00007fffbe498030 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffbe4990c0 R13: 00007ff0cee13d7d R14: 00000000000255b2 R15: 00007fffbe499100 Showing all locks held in the system: 4 locks held by kworker/u4:1/11: #0: ffff888145240138 ( (wq_completion)writeback ){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000107d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff88807d2a2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] #2: ffff88807d2a2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88805e7827d8 (&xfs_nondir_ilock_class){++++}-{3:3} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] , at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b630 (rcu_tasks.tasks_gp_mutex ){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2be50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2aca0 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] , at: rcu_read_lock include/linux/rcupdate.h:791 [inline] , at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 4 locks held by kworker/u4:2/39: #0: ffff888145240138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b07d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff8880778e2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] ffff8880778e2650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88805c41f558 (&xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] , at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 4 locks held by kworker/u4:3/46: #0: ffff888145240138 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90000b77d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888028784650 ( sb_internal #2){.+.+}-{0:0} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] , at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88805e782018 ( &xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] , at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 4 locks held by kworker/u4:4/75: #0: ffff888145240138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90001577d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888077b9c650 (sb_internal #2 ){.+.+}-{0:0} , at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4571 [inline] , at: xfs_bmapi_convert_delalloc+0x2fd/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 #3: ffff88805c419098 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_one_delalloc fs/xfs/libxfs/xfs_bmap.c:4576 [inline] #3: ffff88805c419098 (&xfs_nondir_ilock_class){++++}-{3:3}, at: xfs_bmapi_convert_delalloc+0x329/0x1480 fs/xfs/libxfs/xfs_bmap.c:4698 2 locks held by getty/4027: #0: ffff88814d3ea098 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 ( &ldata->atomic_read_lock ){+.+.}-{3:3} , at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 2 locks held by kworker/0:9/4358: #0: ffff888017472138 ( (wq_completion)rcu_gp ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900032d7d00 ( (work_completion)(&rew->rew_work) ){+.+.}-{0:0} , at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 2 locks held by syz-executor/4393: #0: ffff888077b9c0e0 ( &type->s_umount_key #53 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff88814436c7d0 ( &bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748 2 locks held by syz-executor/4459: #0: ffff8880287840e0 ( &type->s_umount_key #53 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff88814437a7d0 (&bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748 2 locks held by syz-executor/4488: #0: ffff8880778e20e0 ( &type->s_umount_key #53 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff888024ad87d0 ( &bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748 2 locks held by syz-executor/4520: #0: ffff88807d2a20e0 ( &type->s_umount_key #53 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffff888024ade7d0 ( &bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x19c/0x9e0 fs/fs-writeback.c:2748 2 locks held by syz-executor/4557: #0: ffff88807447c0e0 (&type->s_umount_key#53){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:362 #1: ffffffff8cb30978 ( rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline] rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4356 Comm: kworker/0:7 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 Workqueue: xfs-buf/loop2 xfs_buf_ioend_work RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 02 79 09 fd 44 89 f9 d3 e3 49 83 c6 40 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 e3 a7 59 fd 41 03 1e 89 da ec <0f> b6 c0 5b 41 5c 41 5e 41 5f c3 44 89 f9 80 e1 07 38 c1 7c aa 4c RSP: 0018:ffffc90002e972f8 EFLAGS: 00000006 RAX: 1ffffffff2dee005 RBX: 00000000000003f9 RCX: 0000000000000000 RDX: 00000000000003f9 RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc90002e974f0 R08: 0000000000000004 R09: 0000000000000003 R10: fffff520005d2e40 R11: 1ffff920005d2e40 R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff96f704c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005615dc303a38 CR3: 000000000c88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_port_in include/linux/serial_core.h:668 [inline] serial8250_console_write+0x247/0x17a0 drivers/tty/serial/8250/8250_port.c:3437 call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0x947/0xc90 kernel/printk/printk.c:2777 console_flush_all kernel/printk/printk.c:-1 [inline] console_unlock+0x223/0x630 kernel/printk/printk.c:2906 vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303 _printk+0xcc/0x110 kernel/printk/printk.c:2328 print_hex_dump+0x1a5/0x260 lib/hexdump.c:285 xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:110 xfs_buf_verifier_error+0x1c8/0x290 fs/xfs/xfs_error.c:441 xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 xfs_buf_ioend+0x27a/0x780 fs/xfs/xfs_buf.c:1303 process_one_work+0x898/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295