INFO: task syz.2.1798:24948 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.1798 state:D stack:23136 pid:24948 tgid:24947 ppid:22583 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5298 [inline] __schedule+0x1553/0x5240 kernel/sched/core.c:6911 __schedule_loop kernel/sched/core.c:6993 [inline] schedule+0x164/0x360 kernel/sched/core.c:7008 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common kernel/sched/completion.c:121 [inline] wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion+0x2cc/0x5e0 kernel/sched/completion.c:153 kthread_flush_worker+0x138/0x1a0 kernel/kthread.c:1579 __alloc_workqueue+0xfed/0x1e90 kernel/workqueue.c:5861 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:5884 scrub_workers_get+0x1db/0x490 fs/btrfs/scrub.c:3064 btrfs_scrub_dev+0x26d/0x11a0 fs/btrfs/scrub.c:3121 btrfs_ioctl_scrub+0x246/0x4b0 fs/btrfs/ioctl.c:3039 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl+0xff/0x170 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7ed461c799 RSP: 002b:00007f7ed286e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f7ed4895fa0 RCX: 00007f7ed461c799 RDX: 0000200000000280 RSI: 00000000c400941b RDI: 0000000000000003 RBP: 00007f7ed46b2c99 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f7ed4896038 R14: 00007f7ed4895fa0 R15: 00007ffd2542b308 Showing all locks held in the system: 1 lock held by kauditd/37: 1 lock held by khungtaskd/38: #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8ddcba80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:3/57: 7 locks held by kworker/u8:4/59: 2 locks held by getty/5554: #0: ffff888036fd50a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003e8b2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13c0 drivers/tty/n_tty.c:2211 4 locks held by kworker/u8:12/6121: 4 locks held by syz-executor/22707: 4 locks held by kworker/1:3/22729: 2 locks held by udevd/22878: 1 lock held by udevd/23040: 1 lock held by syz.2.1798/24948: #0: ffff8880676c2480 (sb_writers#14){.+.+}-{0:0}, at: mnt_want_write_file+0x63/0x210 fs/namespace.c:537 1 lock held by iou-sqp-27560/27613: 1 lock held by syz.8.2052/27573: 4 locks held by syz.7.2056/27579: #0: ffff88803ff7a480 (sb_writers#13){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493 #1: ffff88805c341490 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: inode_lock_killable include/linux/fs.h:1033 [inline] #1: ffff88805c341490 (&sb->s_type->i_mutex_key#25){++++}-{4:4}, at: do_truncate+0x18f/0x250 fs/open.c:63 #2: ffff88805c341660 (mapping.invalidate_lock#7){++++}-{4:4}, at: xfs_ilock+0x16d/0x3b0 fs/xfs/xfs_inode.c:157 #3: ffffffff8da167c8 (&folio_wait_table[i]){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #3: ffffffff8da167c8 (&folio_wait_table[i]){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394 1 lock held by syz.7.2056/27645: #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124 1 lock held by udevadm/27597: #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124 4 locks held by syz.1.2057/27624: 1 lock held by cmp/27639: #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline] #0: ffffffff8de20c38 (kauditd_wait.lock){+.+.}-{3:3}, at: __wake_up_common_lock+0x2f/0x1e0 kernel/sched/wait.c:124 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 kernel/hung_task.c:515 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 27624 Comm: syz.1.2057 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:81 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:103 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:238 [inline] RIP: 0010:unwind_next_frame+0x513/0x23c0 arch/x86/kernel/unwind_orc.c:510 Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 RSP: 0018:ffffc90016eef178 EFLAGS: 00000a07 RAX: 0000000000000000 RBX: ffffffff8f89cc98 RCX: dffffc0000000000 RDX: ffffffff8f89cc70 RSI: ffffffff90041406 RDI: ffffffff8ba671a0 RBP: ffffffff8f89cc70 R08: 000000000000000b R09: ffffffff8ddcba80 R10: ffffc90016eef298 R11: ffffffff81af89e0 R12: ffffffff821ca56a R13: ffffffff8f89cc70 R14: ffffc90016eef248 R15: ffffffff8f89cc84 FS: 00007f8b41c0c6c0(0000) GS:ffff888126439000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007efd53d13000 CR3: 0000000075660000 CR4: 00000000003526f0 Call Trace: arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x124/0x230 mm/page_owner.c:165 __set_page_owner+0x8d/0x4b0 mm/page_owner.c:341 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2484 folio_alloc_mpol_noprof+0x39/0xe0 mm/mempolicy.c:2503 shmem_alloc_folio mm/shmem.c:1930 [inline] shmem_alloc_and_add_folio mm/shmem.c:1972 [inline] shmem_get_folio_gfp+0x644/0x1a80 mm/shmem.c:2567 shmem_get_folio mm/shmem.c:2673 [inline] shmem_write_begin+0x166/0x320 mm/shmem.c:3327 generic_perform_write+0x2af/0x8b0 mm/filemap.c:4319 shmem_file_write_iter+0xfb/0x120 mm/shmem.c:3502 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x629/0xba0 fs/read_write.c:688 ksys_write+0x156/0x270 fs/read_write.c:740 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f8b439bcfce Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007f8b41c0bda8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f8b41c0c6c0 RCX: 00007f8b439bcfce RDX: 0000000001000000 RSI: 00007f8b397ec000 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000005 R13: 00007f8b41c0bee0 R14: 00007f8b41c0bea0 R15: 00007f8b397ec000