INFO: task kworker/u8:13:3519 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:13 state:D stack:21504 pid:3519 tgid:3519 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn (flush-7:6)
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]
rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7289
rt_mutex_slowlock_block+0x508/0x680 kernel/locking/rtmutex.c:1647
__rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
__rt_mutex_slowlock_locked kernel/locking/rtmutex.c:1760 [inline]
rt_mutex_slowlock+0x2dc/0x7b0 kernel/locking/rtmutex.c:1800
__rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
__mutex_lock_common kernel/locking/rtmutex_api.c:534 [inline]
mutex_lock_nested+0x168/0x1d0 kernel/locking/rtmutex_api.c:552
jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
jfs_write_inode+0x145/0x220 fs/jfs/inode.c:138
write_inode fs/fs-writeback.c:1582 [inline]
__writeback_single_inode+0x75d/0x11a0 fs/fs-writeback.c:1813
writeback_sb_inodes+0x995/0x19d0 fs/fs-writeback.c:2042
__writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2118
wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2229
wb_check_old_data_flush fs/fs-writeback.c:2333 [inline]
wb_do_writeback fs/fs-writeback.c:2386 [inline]
wb_workfn+0xb52/0xf60 fs/fs-writeback.c:2414
process_one_work kernel/workqueue.c:3276 [inline]
process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
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
Showing all locks held in the system:
1 lock held by khungtaskd/37:
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8ddcb980 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by kworker/u8:2/42:
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90000b37c40 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90000b37c40 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
3 locks held by kworker/u8:12/1415:
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888019c44138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc900062cfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc900062cfc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313
4 locks held by kworker/u8:13/3519:
#0: ffff88801f6d8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff88801f6d8938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc9000e86fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc9000e86fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff88805e8000d0 (&type->s_umount_key#86){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
#3: ffff8880603c8ba8 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
2 locks held by getty/5554:
#0: ffff888036a9d0a0 (&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
3 locks held by kworker/u9:4/5806:
#0: ffff888039e1f138 ((wq_completion)hci2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
#0: ffff888039e1f138 ((wq_completion)hci2){+.+.}-{0:0}, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
#1: ffffc90004737c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
#1: ffffc90004737c40 ((work_completion)(&hdev->cmd_sync_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
#2: ffff888025dfcf80 (&hdev->req_lock){+.+.}-{4:4}, at: hci_cmd_sync_work+0x1d3/0x400 net/bluetooth/hci_sync.c:331
1 lock held by udevd/5813:
2 locks held by udevd/5814:
#0: ffff88803751a480 (sb_writers#5){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:493
#1: ffff88803b4cacb8 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:1073 [inline]
#1: ffff88803b4cacb8 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: __start_dirop fs/namei.c:2923 [inline]
#1: ffff88803b4cacb8 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: start_dirop fs/namei.c:2934 [inline]
#1: ffff88803b4cacb8 (&type->i_mutex_dir_key#5/1){+.+.}-{4:4}, at: filename_create+0x200/0x370 fs/namei.c:4922
1 lock held by udevd/6438:
4 locks held by kworker/u8:14/7724:
4 locks held by syz.6.304/8128:
2 locks held by syz-executor/8378:
#0: ffff888025a740d0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock fs/super.c:58 [inline]
#0: ffff888025a740d0 (&type->s_umount_key#86){++++}-{4:4}, at: __super_lock_excl fs/super.c:73 [inline]
#0: ffff888025a740d0 (&type->s_umount_key#86){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:508
#1: ffffffff8e24dbd8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
2 locks held by syz-executor/9206:
2 locks held by syz-executor/10681:
2 locks held by syz.4.511/12162:
#0: ffff888060f580d0 (&type->s_umount_key#86){++++}-{4:4}, at: do_remount fs/namespace.c:3388 [inline]
#0: ffff888060f580d0 (&type->s_umount_key#86){++++}-{4:4}, at: path_mount+0xd7d/0x10e0 fs/namespace.c:4151
#1: ffffffff8e24dbd8 (jfs_log_mutex){+.+.}-{4:4}, at: lmLogClose+0xb4/0x520 fs/jfs/jfs_logmgr.c:1443
3 locks held by syz-executor/12522:
#0: ffffffff8f6c17e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
#0: ffffffff8f6c17e8 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
#0: ffffffff8f6c17e8 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8f15abb8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8a1/0x1be0 net/core/rtnetlink.c:4071
#2: ffff888019c4f238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_add_one+0x41/0x5c0 fs/kernfs/dir.c:796
3 locks held by syz.7.599/12641:
#0: ffff888036dbd588 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0x1d1/0x500 mm/mmap_lock.c:310
#1: ffff8880608105f8 (sb_pagefaults#4){.+.+}-{0:0}, at: do_page_mkwrite+0x150/0x310 mm/memory.c:3589
#2: ffff88805de8ade8 (&ei->i_mmap_lock){++++}-{4:4}, at: btrfs_page_mkwrite+0x60e/0x1b10 fs/btrfs/file.c:1918
4 locks held by syz.7.599/12781:
#0: ffff888060810480 (sb_writers#21){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
#0: ffff888060810480 (sb_writers#21){.+.+}-{0:0}, at: vfs_copy_file_range+0x9bb/0x1390 fs/read_write.c:1588
#1: ffff88805de8af88 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
#1: ffff88805de8af88 (&sb->s_type->i_mutex_key#33){++++}-{4:4}, at: btrfs_inode_lock+0x51/0xe0 fs/btrfs/inode.c:369
#2: ffff88805de8ade8 (&ei->i_mmap_lock){++++}-{4:4}, at: btrfs_inode_lock+0xcb/0xe0 fs/btrfs/inode.c:372
#3: ffff8880356cb5f8 (&entry->wait){+.+.}-{3:3}, at: spin_lock include/linux/spinlock_rt.h:45 [inline]
#3: ffff8880356cb5f8 (&entry->wait){+.+.}-{3:3}, at: finish_wait+0xbe/0x1e0 kernel/sched/wait.c:394
4 locks held by dhcpcd-run-hook/12790:
1 lock held by syz.1.600/12817:
#0: ffff8880441803b0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock_killable include/linux/mmap_lock.h:554 [inline]
#0: ffff8880441803b0 (&mm->mmap_lock){++++}-{4:4}, at: vm_mmap_pgoff+0x237/0x4f0 mm/util.c:579
1 lock held by syz.1.600/12823:
1 lock held by udevadm/12822:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 37 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12822 Comm: udevadm Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:memset_orig+0x36/0xb0 arch/x86/lib/memset_64.S:70
Code: 01 01 01 01 01 48 0f af c1 41 89 f9 41 83 e1 07 75 74 48 89 d1 48 c1 e9 06 74 39 66 0f 1f 84 00 00 00 00 00 48 ff c9 48 89 07 <48> 89 47 08 48 89 47 10 48 89 47 18 48 89 47 20 48 89 47 28 48 89
RSP: 0018:ffffc900042975b0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffff88802b15e3c0 RCX: 0000000000000003
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff88802b15e3c0
RBP: ffffc90004297c10 R08: ffff88802b15e4bf R09: 0000000000000000
R10: ffff88802b15e3c0 R11: ffffed100562bc98 R12: dffffc0000000000
R13: ffffc90004297800 R14: ffff88802b15e3c0 R15: ffff8880441872c0
FS: 0000000000000000(0000) GS:ffff88812633c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a720d9250 CR3: 000000003404a000 CR4: 00000000003526f0
Call Trace:
vma_init include/linux/mm.h:911 [inline]
vm_area_alloc+0x51/0x140 mm/vma_init.c:36
__mmap_new_vma mm/vma.c:2517 [inline]
__mmap_region mm/vma.c:2759 [inline]
mmap_region+0x112c/0x2230 mm/vma.c:2837
do_mmap+0xc2f/0x10c0 mm/mmap.c:559
vm_mmap_pgoff+0x2cc/0x4f0 mm/util.c:581
ksys_mmap_pgoff+0x4e8/0x720 mm/mmap.c:605
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: 0033:0x7f3a7210d242
Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00
RSP: 002b:00007ffdd812da68 EFLAGS: 00000206 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f3a72080000 RCX: 00007f3a7210d242
RDX: 0000000000000003 RSI: 0000000000002000 RDI: 00007f3a72080000
RBP: 0000000000000812 R08: 0000000000000003 R09: 000000000002c000
R10: 0000000000000812 R11: 0000000000000206 R12: 00007ffdd812db28
R13: 00007f3a720e15f0 R14: 00007ffdd812dee0 R15: 00000fffbb025b50