INFO: task kworker/u4:9:3455 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u4:9    state:D stack:22680 pid:3455  ppid:2      flags:0x00004000
Workqueue: writeback wb_workfn (flush-7:3)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 __mutex_lock_common kernel/locking/mutex.c:679 [inline]
 __mutex_lock+0x673/0xc80 kernel/locking/mutex.c:747
 hfsplus_ext_write_extent+0x91/0x230 fs/hfsplus/extents.c:149
 hfsplus_write_inode+0x22/0x590 fs/hfsplus/super.c:171
 write_inode fs/fs-writeback.c:1549 [inline]
 __writeback_single_inode+0x720/0xee0 fs/fs-writeback.c:1766
 writeback_sb_inodes+0x813/0x1020 fs/fs-writeback.c:1992
 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2063
 wb_writeback+0x472/0xbe0 fs/fs-writeback.c:2173
 wb_check_background_flush fs/fs-writeback.c:2243 [inline]
 wb_do_writeback fs/fs-writeback.c:2331 [inline]
 wb_workfn+0xb8e/0xe60 fs/fs-writeback.c:2358
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 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>
INFO: task syz-executor:5776 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor    state:D stack:21800 pid:5776  ppid:1      flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6834
 rwsem_down_write_slowpath+0xc3f/0x1020 kernel/locking/rwsem.c:1178
 __down_write_common kernel/locking/rwsem.c:1306 [inline]
 __down_write kernel/locking/rwsem.c:1315 [inline]
 down_write+0x1b9/0x200 kernel/locking/rwsem.c:1574
 inode_lock include/linux/fs.h:804 [inline]
 vfs_unlink+0xde/0x600 fs/namei.c:4369
 do_unlinkat+0x339/0x590 fs/namei.c:4446
 __do_sys_unlink fs/namei.c:4494 [inline]
 __se_sys_unlink fs/namei.c:4492 [inline]
 __x64_sys_unlink+0x49/0x50 fs/namei.c:4492
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fe8d8b9d647
RSP: 002b:00007ffe990e56c8 EFLAGS: 00000206 ORIG_RAX: 0000000000000057
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe8d8b9d647
RDX: 00007ffe990e56f0 RSI: 00007ffe990e5780 RDI: 00007ffe990e5780
RBP: 00007ffe990e5780 R08: 00007ffe990e6780 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe990e6870
R13: 00007fe8d8c34efb R14: 0000000000019f58 R15: 00007ffe990e7940
 </TASK>
INFO: task syz.3.25:5991 blocked for more than 145 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.25        state:D stack:20976 pid:5991  ppid:5776   flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x15ae/0x4660 kernel/sched/core.c:6701
 schedule+0xbd/0x170 kernel/sched/core.c:6775
 hfsplus_bnode_find+0x345/0xd00 fs/hfsplus/bnode.c:539
 hfs_bnode_split+0x29b/0xee0 fs/hfsplus/brec.c:258
 hfsplus_brec_insert+0x398/0xcd0 fs/hfsplus/brec.c:100
 __hfsplus_ext_write_extent+0x318/0x520 fs/hfsplus/extents.c:107
 __hfsplus_ext_cache_extent+0x81/0xbd0 fs/hfsplus/extents.c:186
 hfsplus_ext_read_extent fs/hfsplus/extents.c:218 [inline]
 hfsplus_file_extend+0x4b9/0x1af0 fs/hfsplus/extents.c:459
 hfsplus_get_block+0x421/0x1520 fs/hfsplus/extents.c:245
 __block_write_begin_int+0x571/0x1b00 fs/buffer.c:2124
 __block_write_begin fs/buffer.c:2173 [inline]
 block_write_begin+0x9a/0x1e0 fs/buffer.c:2234
 cont_write_begin+0x5fd/0x800 fs/buffer.c:2591
 hfsplus_write_begin+0x8b/0xd0 fs/hfsplus/inode.c:52
 generic_perform_write+0x2fe/0x5c0 mm/filemap.c:4036
 generic_file_write_iter+0xaf/0x2e0 mm/filemap.c:4157
 __kernel_write_iter+0x29f/0x6d0 fs/read_write.c:517
 dump_emit_page fs/coredump.c:958 [inline]
 dump_user_range+0x418/0x840 fs/coredump.c:985
 elf_core_dump+0x320e/0x37c0 fs/binfmt_elf.c:2184
 do_coredump+0x1791/0x24a0 fs/coredump.c:834
 get_signal+0x10da/0x1390 kernel/signal.c:2901
 arch_do_signal_or_restart+0xc2/0x7b0 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:213
 irqentry_exit_to_user_mode+0x9/0x30 kernel/entry/common.c:318
 exc_page_fault+0x8c/0x100 arch/x86/mm/fault.c:1519
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7fe8d8b9e561
RSP: 002b:fffffffffffffe70 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fe8d8e26090 RCX: 00007fe8d8b9e559
RDX: 0000000000000000 RSI: fffffffffffffe70 RDI: 0000000000008000
RBP: 00007fe8d8c35ab8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fe8d8e26128 R14: 00007fe8d8e26090 R15: 00007ffe990e7548
 </TASK>

Showing all locks held in the system:
5 locks held by kworker/u4:1/12:
 #0: ffff88801ae5d138 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff88801ae5d138 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc90000117d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffffffff8f1c5810 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x140/0xb00 net/core/net_namespace.c:610
 #3: ffff888021cc8250 (&devlink->lock_key#5){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:60 [inline]
 #3: ffff888021cc8250 (&devlink->lock_key#5){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0xee/0x360 net/devlink/core.c:285
 #4: ffffffff8df37980 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:4089
1 lock held by khungtaskd/29:
 #0: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8df320e0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x290 kernel/locking/lockdep.c:6669
2 locks held by kworker/1:2/970:
 #0: ffff888018872d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888018872d38 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc900041e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc900041e7d00 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
4 locks held by kworker/u4:9/3455:
 #0: ffff888141641938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #0: ffff888141641938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #1: ffffc9000c8a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2632 [inline]
 #1: ffffc9000c8a7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x975/0x1600 kernel/workqueue.c:2734
 #2: ffff888031f820e0 (&type->s_umount_key#59){++++}-{3:3}, at: super_trylock_shared+0x20/0xf0 fs/super.c:607
 #3: ffff888031ceae88 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_ext_write_extent+0x91/0x230 fs/hfsplus/extents.c:149
2 locks held by syslogd/5124:
 #0: ffff8880b8c3c258 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x9c/0x130 kernel/sched/core.c:567
 #1: ffff8880b8c28a00 (psi_seq){-.-.}-{0:0}, at: psi_sched_switch kernel/sched/stats.h:189 [inline]
 #1: ffff8880b8c28a00 (psi_seq){-.-.}-{0:0}, at: __schedule+0x21d3/0x4660 kernel/sched/core.c:6696
2 locks held by getty/5537:
 #0: ffff8880324920a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000328b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x428/0x1370 drivers/tty/n_tty.c:2217
3 locks held by syz-executor/5776:
 #0: ffff888031f82418 (sb_writers#16){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:412
 #1: ffff888031ce9cc0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: inode_lock_nested include/linux/fs.h:839 [inline]
 #1: ffff888031ce9cc0 (&type->i_mutex_dir_key#8/1){+.+.}-{3:3}, at: do_unlinkat+0x18d/0x590 fs/namei.c:4431
 #2: ffff888031ceb040 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #2: ffff888031ceb040 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: vfs_unlink+0xde/0x600 fs/namei.c:4369
4 locks held by syz-executor/5779:
 #0: ffff88802d3e8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
 #0: ffff88802d3e8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
 #1: ffff88802d3e80b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x552/0x1170 net/bluetooth/hci_sync.c:5396
 #2: ffffffff8f341368 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_disconn_cfm include/net/bluetooth/hci_core.h:2016 [inline]
 #2: ffffffff8f341368 (hci_cb_list_lock){+.+.}-{3:3}, at: hci_conn_hash_flush+0x99/0x220 net/bluetooth/hci_conn.c:2592
 #3: ffff888024ffa338 (&conn->lock#2){+.+.}-{3:3}, at: l2cap_conn_del+0x7b/0x630 net/bluetooth/l2cap_core.c:1796
4 locks held by syz.3.25/5991:
 #0: ffff888031f82418 (sb_writers#16){.+.+}-{0:0}, at: do_coredump+0x1774/0x24a0 fs/coredump.c:833
 #1: ffff888031ceb040 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:804 [inline]
 #1: ffff888031ceb040 (&sb->s_type->i_mutex_key#22){+.+.}-{3:3}, at: generic_file_write_iter+0x83/0x2e0 mm/filemap.c:4154
 #2: ffff888031ceae88 (&hip->extents_lock){+.+.}-{3:3}, at: hfsplus_file_extend+0x213/0x1af0 fs/hfsplus/extents.c:455
 #3: ffff8880782d20b0 (&tree->tree_lock/1){+.+.}-{3:3}, at: hfsplus_find_init+0x154/0x1d0 fs/hfsplus/bfind.c:28
3 locks held by syz.1.56/6108:
 #0: ffff8880272e8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_dev_do_close net/bluetooth/hci_core.c:521 [inline]
 #0: ffff8880272e8e70 (&hdev->req_lock){+.+.}-{3:3}, at: hci_unregister_dev+0x212/0x500 net/bluetooth/hci_core.c:2709
 #1: ffff8880272e80b8 (&hdev->lock){+.+.}-{3:3}, at: hci_dev_close_sync+0x552/0x1170 net/bluetooth/hci_sync.c:5396
 #2: ffffffff8df37ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #2: ffffffff8df37ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004
1 lock held by syz.2.245/6988:
 #0: ffffffff8df37ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:324 [inline]
 #0: ffffffff8df37ab8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3da/0x880 kernel/rcu/tree_exp.h:1004

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

NMI backtrace for cpu 0
CPU: 0 PID: 29 Comm: khungtaskd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a6/0x3e0 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+0xf59/0xfa0 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3543 Comm: kworker/u4:12 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0x9c/0x320 kernel/locking/lockdep.c:4684
Code: 89 c7 41 81 e7 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 00 15 ff 91 be 08 00 00 00 e8 5c 1a 77 00 4c 0f a3 3d b4 bb 95 10 <73> 10 49 69 c7 d0 00 00 00 4c 8d b8 c0 93 95 91 eb 24 48 c7 c0 80
RSP: 0018:ffffc9000ce177c0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: ffff88802f213c00 RCX: ffffffff81695944
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff91ff15e8
RBP: 0000000000000006 R08: ffffffff91ff15ef R09: 1ffffffff23fe2bd
R10: dffffc0000000000 R11: fffffbfff23fe2be R12: 0000000000000040
R13: dffffc0000000000 R14: ffff88802f214710 R15: 000000000000076b
FS:  0000000000000000(0000) GS:ffff8880b8d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff9fa6f1664 CR3: 000000000dd32000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 mark_held_locks kernel/locking/lockdep.c:4302 [inline]
 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4328 [inline]
 lockdep_hardirqs_on_prepare+0x384/0x7d0 kernel/locking/lockdep.c:4387
 trace_hardirqs_on+0x28/0x40 kernel/trace/trace_preemptirq.c:61
 crng_make_state+0x350/0x700 drivers/char/random.c:365
 _get_random_bytes+0x100/0x250 drivers/char/random.c:378
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:776 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x60c/0xa90 drivers/net/netdevsim/dev.c:851
 process_one_work kernel/workqueue.c:2657 [inline]
 process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
 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>