INFO: task syz-executor:4720 blocked for more than 143 seconds. Not tainted 5.15.182-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:21760 pid: 4720 ppid: 1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 wb_wait_for_completion+0x164/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1b3/0x920 fs/fs-writeback.c:2770 sync_filesystem+0x16d/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x300 fs/super.c:448 kill_block_super+0x7c/0xe0 fs/super.c:1427 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1143 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff16cd4ea47 RSP: 002b:00007ffd96a99278 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007ff16cdc01cc RCX: 00007ff16cd4ea47 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffd96a99330 RBP: 00007ffd96a99330 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffd96a9a3b0 R13: 00007ff16cdc01cc R14: 000000000001cc27 R15: 00007ffd96a9a3f0 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff8880191c8938 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88807a690650 (sb_internal#2){.+.+}-{0:0}, at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573 #3: ffff88806d872668 (&xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578 1 lock held by khungtaskd/27: #0: ffffffff8c11bea0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by kworker/u4:1/144: #0: ffff888016879138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc900016bfd00 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 4 locks held by kworker/u4:2/154: #0: ffff8880191c8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90001fd7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88807f0dc650 ( sb_internal #2 ){.+.+}-{0:0} , at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573 #3: ffff88805c9e4be8 (&xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578 2 locks held by kworker/u4:3/467: #0: ffff888016879138 ( (wq_completion)events_unbound ){+.+.}-{0:0} , at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002f5fd00 ( (reaper_work).work ){+.+.}-{0:0} , at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 4 locks held by kworker/u4:4/1480: #0: ffff8880191c8938 ( (wq_completion)writeback ){+.+.}-{0:0} , at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90004f37d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff88807b040650 ( sb_internal #2 ){.+.+}-{0:0} , at: xfs_bmapi_convert_delalloc+0x1f1/0xd90 fs/xfs/libxfs/xfs_bmap.c:4573 #3: ffff88805c9e00e8 ( &xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_delalloc+0x21e/0xd90 fs/xfs/libxfs/xfs_bmap.c:4578 2 locks held by getty/3939: #0: ffff88802b676098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc90002cd62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158 4 locks held by kworker/u4:5/4197: #0: ffff8880191c8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x760/0x1000 kernel/workqueue.c:-1 #1: ffffc90002edfd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a3/0x1000 kernel/workqueue.c:2285 #2: ffff8880b913a318 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 #3: ffff888074279720 (&local->rx_path_lock){+.-.}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline] #3: ffff888074279720 (&local->rx_path_lock){+.-.}-{2:2}, at: ieee80211_rx_handlers+0xe6/0x8470 net/mac80211/rx.c:3924 5 locks held by kworker/1:22/4646: 2 locks held by syz-executor/4720: #0: ffff88807b0400e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff8881476687d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff8881476687d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768 2 locks held by syz-executor/5017: #0: ffff888077cb20e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff88814766e7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88814766e7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768 2 locks held by syz-executor/5053: #0: ffff88807f0dc0e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff88801fe6c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88801fe6c7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768 2 locks held by syz-executor/5107: #0: ffff88807a6900e0 (&type->s_umount_key#52){+.+.}-{3:3}, at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff88801fe7a7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff88801fe7a7d8 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x197/0x920 fs/fs-writeback.c:2768 1 lock held by syz-executor/5173: #0: ffffffff8c120928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline] #0: ffffffff8c120928 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 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+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4646 Comm: kworker/1:22 Not tainted 5.15.182-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: xfs-buf/loop3 xfs_buf_ioend_work RIP: 0010:io_serial_in+0x73/0xb0 drivers/tty/serial/8250/8250_port.c:461 Code: e8 f2 d6 31 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 03 4a 77 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:ffffc9000303f370 EFLAGS: 00000002 RAX: 1ffffffff2c78f00 RBX: 00000000000003fd RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: 0000000000000020 R08: 0000000000000004 R09: 0000000000000003 R10: fffff52000607e64 R11: 1ffff92000607e64 R12: dffffc0000000000 R13: ffffffff963c7be8 R14: ffffffff963c7980 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa150feef98 CR3: 000000007dc36000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: serial_in drivers/tty/serial/8250/8250.h:116 [inline] wait_for_xmitr+0xe9/0x260 drivers/tty/serial/8250/8250_port.c:2069 serial8250_console_putchar+0x1a/0x50 drivers/tty/serial/8250/8250_port.c:3310 uart_console_write+0xaa/0x100 drivers/tty/serial/serial_core.c:1981 serial8250_console_write+0xbb5/0xf80 drivers/tty/serial/8250/8250_port.c:3387 call_console_drivers kernel/printk/printk.c:-1 [inline] console_unlock+0xc86/0x1200 kernel/printk/printk.c:2744 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xcc/0x110 kernel/printk/printk.c:2299 print_hex_dump+0x1a5/0x260 lib/hexdump.c:285 xfs_hex_dump+0x39/0x50 fs/xfs/xfs_message.c:118 xfs_buf_verifier_error+0x1ba/0x290 fs/xfs/xfs_error.c:418 xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 xfs_buf_ioend+0x25c/0x6e0 fs/xfs/xfs_buf.c:1263 process_one_work+0x863/0x1000 kernel/workqueue.c:2310 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287