INFO: task kworker/u4:3:46 blocked for more than 151 seconds.
Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:3 state:D stack:22472 pid:46 ppid:2 flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:1)
Call Trace:
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6696
__mutex_lock_common kernel/locking/mutex.c:679 [inline]
__mutex_lock+0x555/0xaf0 kernel/locking/mutex.c:747
hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
hfsplus_cat_write_inode+0x1e3/0x820 fs/hfsplus/inode.c:590
write_inode fs/fs-writeback.c:1470 [inline]
__writeback_single_inode+0x75b/0x1160 fs/fs-writeback.c:1687
writeback_sb_inodes+0xad8/0x17d0 fs/fs-writeback.c:1913
__writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:1984
wb_writeback+0x47a/0xd00 fs/fs-writeback.c:2089
wb_check_old_data_flush fs/fs-writeback.c:2189 [inline]
wb_do_writeback fs/fs-writeback.c:2242 [inline]
wb_workfn+0xb66/0xec0 fs/fs-writeback.c:2270
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Showing all locks held in the system:
1 lock held by rcu_tasks_kthre/12:
#0: ffffffff8c92bab0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
1 lock held by rcu_tasks_trace/13:
#0: ffffffff8c92c2d0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517
3 locks held by kworker/1:0/22:
#0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900001c7d00 (deferred_process_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2:
ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}
, at: switchdev_deferred_process_work+0xa/0x20 net/switchdev/switchdev.c:104
1 lock held by khungtaskd/27:
#0:
ffffffff8c92b120
(
rcu_read_lock
){....}-{1:2}
, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513
4 locks held by kworker/u4:3/46:
#0: ffff888143e65938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90000b77d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2:
ffff88807e03c0e0
(&type->s_umount_key#54){++++}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:415
#3: ffff88807e5780b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28
1 lock held by dhcpcd/3931:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: devinet_ioctl+0x288/0x1af0 net/ipv4/devinet.c:1080
2 locks held by getty/4021:
#0: ffff88814dcc0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244
#1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198
2 locks held by kworker/0:3/4267:
#0: ffff888017472138 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900041a7d00
((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
5 locks held by kworker/u4:7/4409:
#0:
ffff888017616938
(
(wq_completion)netns
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc9000506fd00
(
net_cleanup_work
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2:
ffffffff8db2e6d0
(
pernet_ops_rwsem
){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffffffff8db3b3a8
(rtnl_mutex){+.+.}-{3:3}, at: default_device_exit_batch+0xe5/0xa50 net/core/dev.c:11489
#4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:291 [inline]
#4: ffffffff8c930df8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x455/0x830 kernel/rcu/tree_exp.h:962
9 locks held by syz.1.220/5057:
3 locks held by kworker/1:14/5107:
#0: ffff88802f55f538
(
(wq_completion)ipv6_addrconf
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc90004fffd00
(
(work_completion)(&(&ifa->dad_work)->work)
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2:
ffffffff8db3b3a8
(
rtnl_mutex
){+.+.}-{3:3}
, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
3 locks held by kworker/u4:17/5674:
#0:
ffff888017479138
(
(wq_completion)events_unbound
){+.+.}-{0:0}
, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1:
ffffc90005457d00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xa/0x50 net/core/link_watch.c:263
3 locks held by kworker/0:13/6356:
#0: ffff88802f55f538 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc90004207d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4131
2 locks held by syz.8.534/6476:
#0: ffffffff8db9b3f0 (cb_lock){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860
#1: ffffffff8db3b3a8
(rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5b/0x930 net/wireless/nl80211.c:16235
1 lock held by syz.9.540/6485:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}
, at: __tun_chr_ioctl+0x3ab/0x1e10 drivers/net/tun.c:3104
1 lock held by syz.9.540/6496:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.9.540/6498:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.9.540/6502:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: __netlink_dump_start+0x11f/0x6f0 net/netlink/af_netlink.c:2305
1 lock held by syz.9.540/6506:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline]
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6147
1 lock held by syz.6.543/6514:
#0: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: do_ipv6_setsockopt+0x336/0x3b20 net/ipv6/ipv6_sockglue.c:418
2 locks held by syz.7.546/6521:
#0:
ffffffff8db9b3f0
(
cb_lock
){++++}-{3:3}, at: genl_rcv+0x15/0x40 net/netlink/genetlink.c:860
#1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: nl80211_pre_doit+0x5b/0x930 net/wireless/nl80211.c:16235
2 locks held by syz.1.547/6525:
#0: ffffffff8d392e68 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xca/0x1940 drivers/net/ppp/ppp_generic.c:739
#1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_create_interface drivers/net/ppp/ppp_generic.c:3360 [inline]
#1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1070 [inline]
#1: ffffffff8db3b3a8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_ioctl+0x64f/0x1940 drivers/net/ppp/ppp_generic.c:743
1 lock held by syz.1.547/6526:
#0: ffffffff8d392e68 (ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xca/0x1940 drivers/net/ppp/ppp_generic.c:739
1 lock held by syz.1.547/6527:
#0:
ffffffff8d392e68
(
ppp_mutex){+.+.}-{3:3}, at: ppp_ioctl+0xca/0x1940 drivers/net/ppp/ppp_generic.c:739
=============================================
NMI backtrace for cpu 0
CPU: 0 PID: 27 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1d4/0x450 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline]
watchdog+0xeee/0xf30 kernel/hung_task.c:377
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5057 Comm: syz.1.220 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:219
Code: 8b 15 65 8f 81 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 <48> 8b 91 00 16 00 00 48 8b 32 48 8d 7e 01 8b 89 fc 15 00 00 48 39
RSP: 0018:ffffc900042a6e48 EFLAGS: 00000246
RAX: ffffffff8a019514 RBX: dffffc0000000000 RCX: ffff88801af33b80
RDX: 0000000000000002 RSI: 00000000fffffffc RDI: 00000000fffffff6
RBP: 00000000fffffffc R08: ffff88801af33b80 R09: 0000000000000005
R10: 0000000000000030 R11: 0000000000000002 R12: 0000000000000036
R13: 1ffffffff14d99a5 R14: ffffffff8a6ccd28 R15: ffff0a1000000500
FS: 00007fda62d866c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005607838a8000 CR3: 0000000027828000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
format_decode+0x804/0x1330 lib/vsprintf.c:2573
vsnprintf+0xef/0x1a00 lib/vsprintf.c:2757
sprintf+0xd6/0x120 lib/vsprintf.c:3009
print_time kernel/printk/printk.c:1274 [inline]
info_print_prefix+0x152/0x300 kernel/printk/printk.c:1300
record_print_text+0x151/0x420 kernel/printk/printk.c:1349
console_emit_next_record+0x65d/0xc90 kernel/printk/printk.c:2760
console_flush_all kernel/printk/printk.c:-1 [inline]
console_unlock+0x223/0x630 kernel/printk/printk.c:2906
vprintk_emit+0x489/0x680 kernel/printk/printk.c:2303
_printk+0xcc/0x110 kernel/printk/printk.c:2328
hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:60 [inline]
hfsplus_bnode_dump+0x31d/0x440 fs/hfsplus/bnode.c:362
hfsplus_brec_remove+0x476/0x540 fs/hfsplus/brec.c:229
__hfsplus_delete_attr+0x1d1/0x360 fs/hfsplus/attributes.c:299
hfsplus_delete_all_attrs+0x240/0x3a0 fs/hfsplus/attributes.c:378
hfsplus_delete_cat+0x94a/0xd20 fs/hfsplus/catalog.c:425
hfsplus_unlink+0x33c/0x760 fs/hfsplus/dir.c:385
vfs_unlink+0x385/0x600 fs/namei.c:4330
do_unlinkat+0x324/0x560 fs/namei.c:4398
__do_sys_unlinkat fs/namei.c:4441 [inline]
__se_sys_unlinkat fs/namei.c:4434 [inline]
__x64_sys_unlinkat+0xd1/0xe0 fs/namei.c:4434
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fda61f8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fda62d86038 EFLAGS: 00000246 ORIG_RAX: 0000000000000107
RAX: ffffffffffffffda RBX: 00007fda621e5fa0 RCX: 00007fda61f8f749
RDX: 0000000000000000 RSI: 00002000000003c0 RDI: 0000000000000004
RBP: 00007fda62013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda621e6038 R14: 00007fda621e5fa0 R15: 00007ffc1e64b028