INFO: task syz-executor.0:4396 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.0 state:D stack:21840 pid: 4396 ppid: 1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11c3/0x4350 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 wb_wait_for_completion+0x171/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x1bd/0x950 fs/fs-writeback.c:2787 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:1438 deactivate_locked_super+0x93/0xf0 fs/super.c:335 cleanup_mnt+0x426/0x4d0 fs/namespace.c:1148 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:184 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:217 __syscall_exit_to_user_mode_work kernel/entry/common.c:299 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:310 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f593b5d4597 RSP: 002b:00007ffde060bbf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007f593b64896a RCX: 00007f593b5d4597 RDX: 0000000000000000 RSI: 000000000000000a RDI: 00007ffde060bcb0 RBP: 00007ffde060bcb0 R08: 00007ffde060ccb0 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffde060cd70 R13: 00007f593b64896a R14: 0000000000011d71 R15: 0000000000000003 Showing all locks held in the system: 5 locks held by kworker/0:0/7: 1 lock held by khungtaskd/27: #0: ffffffff8d11efa0 ( rcu_read_lock ){....}-{1:2} , at: rcu_lock_acquire+0x0/0x30 4 locks held by kworker/u4:2/152: #0: ffff8881447a4938 ( (wq_completion)writeback){+.+.}-{0:0} , at: process_one_work+0x75c/0xff0 kernel/workqueue.c:-1 #1: ffffc90001e47d00 ( (work_completion)(&(&wb->dwork)->work) ){+.+.}-{0:0} , at: process_one_work+0x79e/0xff0 kernel/workqueue.c:2285 #2: ffff888079542650 ( sb_internal #2 ){.+.+}-{0:0} , at: xfs_bmapi_convert_delalloc+0x224/0xda0 fs/xfs/libxfs/xfs_bmap.c:4573 #3: ffff888071ba1768 ( &xfs_nondir_ilock_class ){++++}-{3:3} , at: xfs_bmapi_convert_delalloc+0x25b/0xda0 fs/xfs/libxfs/xfs_bmap.c:4578 2 locks held by getty/3944: #0: ffff88802d01c098 ( &tty->ldisc_sem ){++++}-{0:0} , at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 ( &ldata->atomic_read_lock ){+.+.}-{3:3} , at: n_tty_read+0x594/0x1a50 drivers/tty/n_tty.c:2158 2 locks held by syz-executor.0/4396: #0: ffff8880795420e0 ( &type->s_umount_key #51 ){+.+.}-{3:3} , at: deactivate_super+0xa0/0xd0 fs/super.c:365 #1: ffff888020daa7d8 ( &bdi->wb_switch_rwsem ){+.+.}-{3:3} , at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] , at: sync_inodes_sb+0x1a1/0x950 fs/fs-writeback.c:2785 ============================================= 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 11/06/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 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+0xe1b/0xe60 kernel/hung_task.c:369 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/06/2026 Workqueue: xfs-buf/loop0 xfs_buf_ioend_work RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:write_comp_data kernel/kcov.c:225 [inline] RIP: 0010:__sanitizer_cov_trace_cmp1+0x4/0x80 kernel/kcov.c:254 Code: 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39 cf 73 08 48 89 44 f2 08 48 89 3a c3 0f 1f 80 00 00 00 00 48 8b 04 24 <65> 48 8b 0d c4 41 89 7e 65 8b 15 c5 41 89 7e 81 e2 00 01 ff 00 74 RSP: 0018:ffffc90000cc73a8 EFLAGS: 00000293 RAX: ffffffff840cbe27 RBX: dffffc0000000000 RCX: 000000008a2be202 RDX: 0000000000000000 RSI: 0000000000000075 RDI: 000000000000006c RBP: 0000000000000075 R08: ffff888017a8bb80 R09: 0000000000000005 R10: 000000000000007a R11: 0000000000000000 R12: ffffffff8a2be289 R13: 000000000000006c R14: 000000000000006c R15: ffffffff8a2be28a FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe02f7bb6c8 CR3: 0000000079b5a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: format_decode+0x6f7/0x1330 lib/vsprintf.c:2608 vsnprintf+0xef/0x1c20 lib/vsprintf.c:2763 sprintf+0xe4/0x140 lib/vsprintf.c:3013 print_time kernel/printk/printk.c:1274 [inline] info_print_prefix+0x168/0x360 kernel/printk/printk.c:1300 record_print_text kernel/printk/printk.c:1349 [inline] console_unlock+0x650/0x10f0 kernel/printk/printk.c:2725 vprintk_emit+0xc0/0x150 kernel/printk/printk.c:2274 _printk+0xda/0x130 kernel/printk/printk.c:2299 __xfs_printk fs/xfs/xfs_message.c:24 [inline] xfs_alert+0x1a7/0x2c0 fs/xfs/xfs_message.c:52 xfs_buf_verifier_error+0x1ae/0x290 fs/xfs/xfs_error.c:416 xfs_allocbt_read_verify+0x53/0xd0 fs/xfs/libxfs/xfs_alloc_btree.c:-1 xfs_buf_ioend+0x256/0x6a0 fs/xfs/xfs_buf.c:1263 process_one_work+0x867/0xff0 kernel/workqueue.c:2310 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457 kthread+0x42e/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287