INFO: task syz.2.755:12329 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.755 state:D stack:25624 pid:12329 tgid:12328 ppid:5801 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x145f/0x5070 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
schedule_timeout+0x9a/0x270 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+0x2bf/0x5d0 kernel/sched/completion.c:153
kthread_flush_worker+0x10e/0x160 kernel/kthread.c:1559
__alloc_workqueue+0x1485/0x1b80 kernel/workqueue.c:5797
alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5820
btrfs_alloc_workqueue+0x1ec/0x2d0 fs/btrfs/async-thread.c:112
btrfs_init_workqueues+0x348/0x680 fs/btrfs/disk-io.c:1986
open_ctree+0x141d/0x3d20 fs/btrfs/disk-io.c:3410
btrfs_fill_super fs/btrfs/super.c:983 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1946 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2089 [inline]
btrfs_get_tree+0x1061/0x1920 fs/btrfs/super.c:2123
vfs_get_tree+0x92/0x2a0 fs/super.c:1751
fc_mount fs/namespace.c:1199 [inline]
do_new_mount_fc fs/namespace.c:3636 [inline]
do_new_mount+0x302/0xa10 fs/namespace.c:3712
do_mount fs/namespace.c:4035 [inline]
__do_sys_mount fs/namespace.c:4224 [inline]
__se_sys_mount+0x313/0x410 fs/namespace.c:4201
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faec08b0eea
RSP: 002b:00007faebeb0de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007faebeb0def0 RCX: 00007faec08b0eea
RDX: 00002000000055c0 RSI: 0000200000000000 RDI: 00007faebeb0deb0
RBP: 00002000000055c0 R08: 00007faebeb0def0 R09: 000000000300000a
R10: 000000000300000a R11: 0000000000000246 R12: 0000200000000000
R13: 00007faebeb0deb0 R14: 00000000000055a3 R15: 0000200000000080
Showing all locks held in the system:
7 locks held by kworker/u8:1/13:
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3232 [inline]
#0: ffff888019ad4938 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x1770 kernel/workqueue.c:3340
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3233 [inline]
#1: ffffc90000127bc0 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x1770 kernel/workqueue.c:3340
#2: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: cleanup_net+0xf7/0x7b0 net/core/net_namespace.c:670
#3: ffff88805b5350d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:895 [inline]
#3: ffff88805b5350d8 (&dev->mutex){....}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline]
#3: ffff88805b5350d8 (&dev->mutex){....}-{4:4}, at: devlink_pernet_pre_exit+0x10a/0x3d0 net/devlink/core.c:506
#4: ffff88805b537300 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_lock net/devlink/core.c:276 [inline]
#4: ffff88805b537300 (&devlink->lock_key#5){+.+.}-{4:4}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline]
#4: ffff88805b537300 (&devlink->lock_key#5){+.+.}-{4:4}, at: devlink_pernet_pre_exit+0x11c/0x3d0 net/devlink/core.c:506
#5: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: nsim_destroy+0xed/0x680 drivers/net/netdevsim/netdev.c:1175
#6: ffff88805b600e98 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock include/linux/netdevice.h:2781 [inline]
#6: ffff88805b600e98 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: netdev_lock_ops include/net/netdev_lock.h:42 [inline]
#6: ffff88805b600e98 (&dev_instance_lock_key#20){+.+.}-{4:4}, at: unregister_netdevice_many_notify+0x1198/0x2330 net/core/dev.c:12370
1 lock held by khungtaskd/38:
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
#0: ffffffff8d5ae940 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
2 locks held by getty/5560:
#0: ffff8880306e30a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
#1: ffffc90003e7e2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x44f/0x1460 drivers/tty/n_tty.c:2211
1 lock held by udevd/5943:
1 lock held by syz.2.755/12329:
#0: ffff8880284d80d0 (&type->s_umount_key#62/1){+.+.}-{4:4}, at: alloc_super+0x28c/0xab0 fs/super.c:344
3 locks held by udevd/13605:
5 locks held by kworker/u8:25/13681:
4 locks held by syz.5.935/14928:
2 locks held by syz-executor/14884:
#0: ffffffff8e898720 (pernet_ops_rwsem){++++}-{4:4}, at: copy_net_ns+0x3cc/0x570 net/core/net_namespace.c:577
#1: ffffffff8e8a5838 (rtnl_mutex){+.+.}-{4:4}, at: ip_tunnel_init_net+0x2ab/0x800 net/ipv4/ip_tunnel.c:1146
1 lock held by udevadm/14927:
=============================================
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 38 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
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:160 [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+0xf95/0xfe0 kernel/hung_task.c:515
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x510/0xa50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 14930 Comm: syz.3.938 Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:hlock_class kernel/locking/lockdep.c:234 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4855 [inline]
RIP: 0010:__lock_acquire+0x3c5/0x2cf0 kernel/locking/lockdep.c:5187
Code: c3 41 0d 48 c7 c6 9f 32 ee 8c 67 48 0f b9 3a 90 31 c0 0f b6 98 c4 00 00 00 41 8b 45 20 25 ff 1f 00 00 48 0f a3 05 cb 2e 1e 11 <73> 17 48 69 c0 c8 00 00 00 48 8d 88 90 b3 5b 92 84 db 75 3f e9 10
RSP: 0000:ffffc9001bfb7a78 EFLAGS: 00000007
RAX: 000000000000086f RBX: 0000000000000000 RCX: 000000000000086f
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff82080447 R09: ffff88802368d808
R10: dffffc0000000000 R11: fffff520037f6f98 R12: 000000000000086f
R13: ffff88801bfb29f8 R14: ffff88801bfb1e40 R15: ffff88801bfb29d0
FS: 00007f987f9666c0(0000) GS:ffff888126cef000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f987780c000 CR3: 000000006e032000 CR4: 00000000003526f0
Call Trace:
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
vma_start_read+0x2bd/0x560 mm/mmap_lock.c:195
lock_vma_under_rcu+0x1a7/0x4a0 mm/mmap_lock.c:259
do_user_addr_fault+0x2d9/0x1380 arch/x86/mm/fault.c:1327
handle_page_fault arch/x86/mm/fault.c:1476 [inline]
exc_page_fault+0x71/0xd0 arch/x86/mm/fault.c:1532
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618
RIP: 0033:0x7f98815c09e6
Code: f0 72 6e 48 63 cd 48 01 c1 49 39 4f 08 72 4c 8d 4d ff 85 ed 74 33 66 0f 1f 44 00 00 48 39 f0 72 1b 4d 8b 07 49 89 c1 49 29 f1 <47> 0f b6 0c 08 45 84 c9 74 08 45 88 0c 00 49 8b 47 10 48 83 c0 01
RSP: 002b:00007f987f9654a0 EFLAGS: 00010206
RAX: 00000000002c6001 RBX: 00007f987f965540 RCX: 0000000000000068
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 00007f987f9655e0
RBP: 0000000000000102 R08: 00007f9877546000 R09: 00000000002c6000
R10: 0000000000000000 R11: 00007f987f965550 R12: 0000000000000001
R13: 00007f988179fc40 R14: 0000000000000000 R15: 00007f987f9655e0