INFO: task kworker/u4:7:1140 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:7    state:D stack:21712 pid:1140  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5380 [inline]
 __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699
 schedule+0xbd/0x170 kernel/sched/core.c:6773
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6832
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x6b7/0xcc0 kernel/locking/mutex.c:747
 hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
 hfsplus_cat_write_inode+0x1e7/0x7b0 fs/hfsplus/inode.c:593
 write_inode fs/fs-writeback.c:1483 [inline]
 __writeback_single_inode+0x705/0xee0 fs/fs-writeback.c:1700
 writeback_sb_inodes+0x77c/0xef0 fs/fs-writeback.c:1926
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:1997
 wb_writeback+0x464/0xba0 fs/fs-writeback.c:2107
 wb_check_background_flush fs/fs-writeback.c:2177 [inline]
 wb_do_writeback fs/fs-writeback.c:2265 [inline]
 wb_workfn+0xb32/0xe20 fs/fs-writeback.c:2292
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>

Showing all locks held in the system:
4 locks held by kworker/u4:0/11:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90000107d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff8880313f40e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88807f25a0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
1 lock held by khungtaskd/29:
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6633
4 locks held by kworker/u4:2/42:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90000b2fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88807c7f20e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88807ad2e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
3 locks held by kworker/u5:0/51:
 #0: 
ffff888023970138
 (
(wq_completion)hci2
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:2609 [inline]
, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: 
ffffc90000bc7d00
 (
(work_completion)(&hdev->cmd_sync_work)
){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88801de90e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_cmd_sync_work+0x1d4/0x390 net/bluetooth/hci_sync.c:326
4 locks held by kworker/u4:5/166:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90002e57d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90002e57d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88806d89c0e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88807f52e0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:6/1121:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000445fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000445fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88807d29c0e0 (
&type->s_umount_key
#56
){++++}-{3:3}
, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: 
ffff88801d7500b0
 (
&tree->tree_lock
){+.+.}-{3:3}
, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:7/1140:
 #0: 
ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000472fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000472fd00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff888022f340e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff888022f300b0
 (
&tree->tree_lock
){+.+.}-{3:3}
, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
4 locks held by kworker/u4:8/4751:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc9000f357d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc9000f357d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff8880313a80e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88807f2560b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
2 locks held by kworker/0:3/5503:
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017872538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc90003847d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc90003847d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
2 locks held by getty/5527:
 #0: ffff88814d0430a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000326e2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x425/0x1380 drivers/tty/n_tty.c:2217
4 locks held by syz.0.17/5945:
4 locks held by syz.1.18/5968:
4 locks held by syz.2.19/5990:
8 locks held by syz.3.20/6020:
4 locks held by kworker/u4:9/6040:
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #0: ffff888017ea8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #1: ffffc900039a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
 #1: ffffc900039a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
 #2: ffff88805d8340e0 (&type->s_umount_key#56){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff88807f56c0b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
4 locks held by syz.4.21/6052:
4 locks held by syz.5.22/6082:
5 locks held by kworker/u4:11/6108:
4 locks held by syz.6.23/6120:

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x39b/0x3d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x2f0 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline]
 watchdog+0xf41/0xf80 kernel/hung_task.c:379
 kthread+0x2fa/0x390 kernel/kthread.c:388
 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5990 Comm: syz.2.19 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:60 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:393 [inline]
RIP: 0010:deref_stack_reg+0xb8/0x240 arch/x86/kernel/unwind_orc.c:403
Code: e8 8d c4 4a 00 85 ed 0f 95 c0 48 8b 2c 24 49 39 ee 0f 96 c1 20 c1 49 39 ec 0f 97 c0 84 c1 74 1e 48 8d 45 08 4c 39 f0 0f 97 c1 <4c> 39 e0 0f 96 c0 84 c1 74 11 e8 a9 c0 4a 00 e9 df 00 00 00 e8 9f
RSP: 0018:ffffc900000075f8 EFLAGS: 00000202
RAX: ffffc900036e7bd0 RBX: 1ffff92000000ee5 RCX: 0000000000000101
RDX: ffff88802b555a00 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900036e7bc8 R08: ffff88802b555a00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900036e8000
R13: 1ffff92000000ee7 R14: ffffc900036e0000 R15: ffffc90000007728
FS:  000055556827a500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558d27c5c8 CR3: 000000001a37b000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 unwind_next_frame+0x1789/0x2970 arch/x86/kernel/unwind_orc.c:648
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x280 mm/slub.c:3852
 mac80211_hwsim_beacon_tx+0x3e9/0x780 drivers/net/wireless/virtual/mac80211_hwsim.c:2269
 __iterate_interfaces+0x243/0x500 net/mac80211/util.c:766
 ieee80211_iterate_active_interfaces_atomic+0xdb/0x180 net/mac80211/util.c:802
 mac80211_hwsim_beacon+0xbb/0x1b0 drivers/net/wireless/virtual/mac80211_hwsim.c:2295
 __run_hrtimer kernel/time/hrtimer.c:1750 [inline]
 __hrtimer_run_queues+0x51e/0xc40 kernel/time/hrtimer.c:1814
 hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1831
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2008 [inline]
RIP: 0010:vprintk_emit+0x44f/0x600 kernel/printk/printk.c:2340
Code: 51 01 00 00 e8 52 55 1b 00 45 89 f7 48 85 db 48 8b 5c 24 08 75 07 e8 40 55 1b 00 eb 06 e8 39 55 1b 00 fb 48 c7 c7 40 42 d2 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 59 bd
RSP: 0018:ffffc900036e7020 EFLAGS: 00000293
RAX: ffffffff816a3b87 RBX: ffffffff816a3a41 RCX: ffff88802b555a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8cd24240
RBP: ffffc900036e7110 R08: ffffffff90d9460f R09: 1ffffffff21b28c1
R10: dffffc0000000000 R11: fffffbfff21b28c2 R12: dffffc0000000000
R13: ffffc900036e7180 R14: 0000000000000060 R15: 0000000000000060
 _printk+0xd0/0x110 kernel/printk/printk.c:2366
 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:60 [inline]
 hfsplus_bnode_dump+0x321/0x440 fs/hfsplus/bnode.c:362
 hfsplus_brec_remove+0x47a/0x550 fs/hfsplus/brec.c:229
 __hfsplus_delete_attr+0x1d5/0x360 fs/hfsplus/attributes.c:299
 hfsplus_delete_attr+0x232/0x2d0 fs/hfsplus/attributes.c:345
 __hfsplus_setxattr+0x48a/0x1f00 fs/hfsplus/xattr.c:346
 hfsplus_setxattr+0x11e/0x170 fs/hfsplus/xattr.c:438
 hfsplus_trusted_setxattr+0x40/0x50 fs/hfsplus/xattr_trusted.c:30
 __vfs_setxattr+0x431/0x470 fs/xattr.c:201
 __vfs_setxattr_noperm+0x12d/0x5e0 fs/xattr.c:235
 vfs_setxattr+0x16c/0x2f0 fs/xattr.c:322
 do_setxattr fs/xattr.c:630 [inline]
 path_setxattr+0x362/0x550 fs/xattr.c:659
 __do_sys_lsetxattr fs/xattr.c:684 [inline]
 __se_sys_lsetxattr fs/xattr.c:680 [inline]
 __x64_sys_lsetxattr+0xb8/0xd0 fs/xattr.c:680
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f62f958f749
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:00007ffdd3382488 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f62f97e5fa0 RCX: 00007f62f958f749
RDX: 00002000000001c0 RSI: 0000200000000180 RDI: 00002000000001c0
RBP: 00007f62f9613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000361 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f62f97e5fa0 R14: 00007f62f97e5fa0 R15: 0000000000000005
 </TASK>