INFO: task syz.3.772:15320 blocked for more than 143 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.772 state:D stack:24728 pid:15320 tgid:15318 ppid:10192 task_flags:0x400140 flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5325 [inline]
__schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
__schedule_loop kernel/sched/core.c:7011 [inline]
schedule+0x165/0x360 kernel/sched/core.c:7026
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+0x1c6/0x240 kernel/kthread.c:1564
__alloc_workqueue+0x1470/0x1b70 kernel/workqueue.c:5795
alloc_workqueue_noprof+0xd4/0x210 kernel/workqueue.c:5818
btrfs_alloc_workqueue+0x1ec/0x2d0 fs/btrfs/async-thread.c:112
btrfs_init_workqueues+0x3ac/0x6c0 fs/btrfs/disk-io.c:1995
open_ctree+0x141d/0x3d20 fs/btrfs/disk-io.c:3426
btrfs_fill_super fs/btrfs/super.c:987 [inline]
btrfs_get_tree_super fs/btrfs/super.c:1952 [inline]
btrfs_get_tree_subvol fs/btrfs/super.c:2089 [inline]
btrfs_get_tree+0xf5a/0x1830 fs/btrfs/super.c:2123
vfs_get_tree+0x92/0x2b0 fs/super.c:1752
do_new_mount+0x2a2/0xa30 fs/namespace.c:3750
do_mount fs/namespace.c:4078 [inline]
__do_sys_mount fs/namespace.c:4278 [inline]
__se_sys_mount+0x317/0x410 fs/namespace.c:4255
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7ee25d066a
RSP: 002b:00007f7ee082de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f7ee082def0 RCX: 00007f7ee25d066a
RDX: 0000200000005100 RSI: 0000200000000280 RDI: 00007f7ee082deb0
RBP: 0000200000005100 R08: 00007f7ee082def0 R09: 0000000000000810
R10: 0000000000000810 R11: 0000000000000246 R12: 0000200000000280
R13: 00007f7ee082deb0 R14: 000000000000510e R15: 00002000000001c0
Showing all locks held in the system:
5 locks held by kworker/u8:1/13:
1 lock held by khungtaskd/38:
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8d3aa300 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:3/57:
3 locks held by kworker/u8:14/2301:
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90006807bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90006807bc0 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:303
1 lock held by udevd/5184:
2 locks held by dhcpcd/5478:
#0: ffffffff8e6c58e0 (cb_lock){++++}-{4:4}, at: genl_rcv+0x19/0x40 net/netlink/genetlink.c:1218
#1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: nl80211_pre_doit+0x5f/0x930 net/wireless/nl80211.c:17927
2 locks held by getty/5574:
#0: ffff88823bf2e0a0 (&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+0x444/0x1400 drivers/tty/n_tty.c:2222
3 locks held by kworker/0:6/5959:
#0: ffff88813ff19138 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff19138 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc900058ffbc0 (deferred_process_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc900058ffbc0 (deferred_process_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
#2: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: switchdev_deferred_process_work+0xe/0x20 net/switchdev/switchdev.c:104
2 locks held by syz-executor/10243:
#0: ffff88802973e0d0 (&type->s_umount_key#70){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
#0: ffff88802973e0d0 (&type->s_umount_key#70){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
#0: ffff88802973e0d0 (&type->s_umount_key#70){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
#1: ffff88813ff34238 (&root->kernfs_rwsem){++++}-{4:4}, at: kernfs_remove_by_name_ns+0x3d/0x130 fs/kernfs/dir.c:1712
2 locks held by kworker/u8:8/11689:
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90013affbc0 ((reaper_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90013affbc0 ((reaper_work).work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
2 locks held by kworker/u8:9/11690:
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
#0: ffff88813ff29938 ((wq_completion)events_unbound#2){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
#1: ffffc90013c6fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
#1: ffffc90013c6fbc0 (connector_reaper_work){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
1 lock held by syz.3.772/15320:
#0: ffff88804ff820d0 (&type->s_umount_key#68/1){+.+.}-{4:4}, at: alloc_super+0x204/0x990 fs/super.c:345
7 locks held by syz-executor/16605:
#0: ffff88803481e488 (sb_writers#7){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3103 [inline]
#0: ffff88803481e488 (sb_writers#7){.+.+}-{0:0}, at: vfs_write+0x217/0xb40 fs/read_write.c:682
#1: ffff888057929478 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1df/0x540 fs/kernfs/file.c:343
#2: ffff888026e07008 (kn->active#52){.+.+}-{0:0}, at: kernfs_get_active_of fs/kernfs/file.c:80 [inline]
#2: ffff888026e07008 (kn->active#52){.+.+}-{0:0}, at: kernfs_fop_write_iter+0x232/0x540 fs/kernfs/file.c:344
#3: ffffffff8ded8698 (nsim_bus_dev_list_lock){+.+.}-{4:4}, at: del_device_store+0xd1/0x360 drivers/net/netdevsim/bus.c:234
#4: ffff8880601c30d8 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:914 [inline]
#4: ffff8880601c30d8 (&dev->mutex){....}-{4:4}, at: __device_driver_lock drivers/base/dd.c:1096 [inline]
#4: ffff8880601c30d8 (&dev->mutex){....}-{4:4}, at: device_release_driver_internal+0xb6/0x800 drivers/base/dd.c:1294
#5: ffff8880325cf300 (&devlink->lock_key#35){+.+.}-{4:4}, at: nsim_drv_remove+0x50/0x160 drivers/net/netdevsim/dev.c:1721
#6: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: unregister_nexthop_notifier+0x17/0x40 net/ipv4/nexthop.c:3999
2 locks held by syz-executor/16971:
#0: ffffffff8ddd1be0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
#0: ffffffff8ddd1be0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
#0: ffffffff8ddd1be0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570
#1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#1: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
1 lock held by syz-executor/17028:
#0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline]
#0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline]
#0: ffffffff8e65f438 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x8e9/0x1c80 net/core/rtnetlink.c:4064
4 locks held by syz-executor/17231:
3 locks held by syz.6.997/17235:
=============================================
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 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
nmi_cpu_backtrace+0x39e/0x3d0 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]
check_hung_uninterruptible_tasks kernel/hung_task.c:332 [inline]
watchdog+0xf60/0xfa0 kernel/hung_task.c:495
kthread+0x711/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148
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: 5184 Comm: udevd Not tainted syzkaller #0 PREEMPT_{RT,(full)}
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:check_preemption_disabled+0x17/0x120 lib/smp_processor_id.c:14
Code: 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 48 83 ec 10 65 48 8b 05 6e 58 cd 06 48 89 44 24 08 <65> 8b 05 76 58 cd 06 65 8b 0d 6b 58 cd 06 f7 c1 ff ff ff 7f 74 23
RSP: 0018:ffffc90003e473a0 EFLAGS: 00000086
RAX: 599a0d30f8601500 RBX: 0000000000000000 RCX: 599a0d30f8601500
RDX: 0000000000000000 RSI: ffffffff8cba6996 RDI: ffffffff8b1d9960
RBP: ffffffff81724d15 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003e47598 R11: ffffffff81a9a810 R12: 0000000000000002
R13: ffffffff8d3aa300 R14: 0000000000000000 R15: 0000000000000246
FS: 00007f35b88ca880(0000) GS:ffff88812703b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7ddbbdf000 CR3: 00000000366f4000 CR4: 00000000003526f0
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline]
lock_acquire+0xe7/0x360 kernel/locking/lockdep.c:5867
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1169 [inline]
unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
save_stack+0xf7/0x1f0 mm/page_owner.c:156
__set_page_owner+0x8d/0x490 mm/page_owner.c:329
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1850
prep_new_page mm/page_alloc.c:1858 [inline]
get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3884
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5183
alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:3030 [inline]
allocate_slab+0x96/0x3a0 mm/slub.c:3203
new_slab mm/slub.c:3257 [inline]
___slab_alloc+0xb12/0x1470 mm/slub.c:4627
__slab_alloc+0xc6/0x1f0 mm/slub.c:4746
__slab_alloc_node mm/slub.c:4822 [inline]
slab_alloc_node mm/slub.c:5233 [inline]
kmem_cache_alloc_noprof+0xec/0x6b0 mm/slub.c:5252
getname_flags+0xb8/0x540 fs/namei.c:146
getname include/linux/fs.h:2914 [inline]
do_sys_openat2+0xbc/0x1c0 fs/open.c:1429
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f35b89b8407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdf116ea80 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f35b88ca880 RCX: 00007f35b89b8407
RDX: 0000000000080000 RSI: 00007ffdf116ebf0 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 0000563a1f5ac7f5
R13: 0000563a1f5ac7f5 R14: 0000000000000001 R15: 00007ffdf1173670