INFO: task kworker/u8:1:13 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u8:1 state:D stack:22216 pid:13 tgid:13 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-7:3) Call Trace: context_switch kernel/sched/core.c:5257 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6864 __schedule_loop kernel/sched/core.c:6946 [inline] schedule+0x165/0x360 kernel/sched/core.c:6961 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7018 __mutex_lock_common kernel/locking/mutex.c:686 [inline] __mutex_lock+0x7e6/0x1350 kernel/locking/mutex.c:770 hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28 hfsplus_cat_write_inode+0x1e6/0x7a0 fs/hfsplus/inode.c:592 write_inode fs/fs-writeback.c:1582 [inline] __writeback_single_inode+0x7e1/0x1240 fs/fs-writeback.c:1802 writeback_sb_inodes+0x93a/0x1870 fs/fs-writeback.c:2030 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2107 wb_writeback+0x43f/0xaa0 fs/fs-writeback.c:2218 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline] wb_do_writeback fs/fs-writeback.c:2375 [inline] wb_workfn+0xad2/0xed0 fs/fs-writeback.c:2403 process_one_work+0x93a/0x15a0 kernel/workqueue.c:3261 process_scheduled_works kernel/workqueue.c:3344 [inline] worker_thread+0x9b0/0xee0 kernel/workqueue.c:3425 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Showing all locks held in the system: 1 lock held by pool_workqueue_/3: #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:343 [inline] #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:956 4 locks held by kworker/u8:1/13: #0: ffff88801f295948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x841/0x15a0 kernel/workqueue.c:3236 #1: ffffc90000127b80 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x868/0x15a0 kernel/workqueue.c:3237 #2: ffff888053dda0e0 (&type->s_umount_key#86){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563 #3: ffff8880763200b0 (&tree->tree_lock#2){+.+.}-{4:4}, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28 1 lock held by khungtaskd/31: #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8df419e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 2 locks held by getty/5580: #0: ffff88814c8230a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x449/0x1460 drivers/tty/n_tty.c:2211 4 locks held by syz.3.97/6395: 1 lock held by syz.1.614/8719: 1 lock held by syz.2.612/8721: #0: ffffffff8df47400 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3816 1 lock held by syz.5.616/8693: #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline] #0: ffffffff8df47538 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2f6/0x730 kernel/rcu/tree_exp.h:956 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 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] __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+0x599/0xb30 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: 6395 Comm: syz.3.97 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:rb_next+0x0/0xe0 lib/rbtree.c:464 Code: c4 28 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 41 57 41 56 53 48 89 fb 49 bf 00 00 00 00 00 fc ff df RSP: 0018:ffffc90000007d00 EFLAGS: 00000006 RAX: ffffffff8b553892 RBX: ffff8880b8628310 RCX: ffff88802b1c9e80 RDX: 0000000000010000 RSI: ffffc90003fafd40 RDI: ffffc90003fafd40 RBP: 1ffff920007f5fa8 R08: ffffffff8f813377 R09: 1ffffffff1f0266e R10: dffffc0000000000 R11: fffffbfff1f0266f R12: ffff8880b8628318 R13: dffffc0000000000 R14: ffffc90003fafd40 R15: 1ffff110170c5063 FS: 00007fea2b5eb6c0(0000) GS:ffff888125e4f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffec29c0ec8 CR3: 00000000113a2000 CR4: 00000000003526f0 Call Trace: rb_erase_cached include/linux/rbtree.h:152 [inline] timerqueue_del+0x8a/0x100 lib/timerqueue.c:57 __remove_hrtimer kernel/time/hrtimer.c:1114 [inline] __run_hrtimer kernel/time/hrtimer.c:1757 [inline] __hrtimer_run_queues+0x364/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_trylock_spinning kernel/printk/printk.c:2037 [inline] RIP: 0010:vprintk_emit+0x4d0/0x5f0 kernel/printk/printk.c:2425 Code: 0f 84 34 ff ff ff e8 4f 62 20 00 fb eb 44 e8 47 62 20 00 e8 c2 10 b8 09 4d 85 f6 74 94 e8 38 62 20 00 fb 48 c7 c7 a0 58 f3 8d <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 53 e8 28 26 RSP: 0018:ffffc9000bba6e80 EFLAGS: 00000246 RAX: ffffffff81a150f8 RBX: ffffffff81a14f51 RCX: 0000000000080000 RDX: ffffc9000cc2c000 RSI: 000000000007ffff RDI: ffffffff8df358a0 RBP: ffffc9000bba6f90 R08: ffffffff8f813377 R09: 1ffffffff1f0266e R10: dffffc0000000000 R11: fffffbfff1f0266f R12: 0000000000000000 R13: 0000000000000060 R14: 0000000000000200 R15: 1ffff92001774dd4 _printk+0xcf/0x120 kernel/printk/printk.c:2451 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:60 [inline] hfsplus_bnode_dump+0x16b/0xa00 fs/hfsplus/bnode.c:362 hfsplus_brec_remove+0x61c/0x700 fs/hfsplus/brec.c:229 __hfsplus_delete_attr+0x1d4/0x360 fs/hfsplus/attributes.c:299 hfsplus_delete_attr+0x239/0x3b0 fs/hfsplus/attributes.c:345 __hfsplus_setxattr+0x396/0x2170 fs/hfsplus/xattr.c:346 hfsplus_setxattr+0x11e/0x180 fs/hfsplus/xattr.c:436 hfsplus_trusted_setxattr+0x40/0x60 fs/hfsplus/xattr_trusted.c:30 __vfs_setxattr+0x43c/0x480 fs/xattr.c:200 __vfs_setxattr_noperm+0x12d/0x660 fs/xattr.c:234 vfs_setxattr+0x16b/0x2f0 fs/xattr.c:321 do_setxattr fs/xattr.c:636 [inline] filename_setxattr+0x274/0x600 fs/xattr.c:665 path_setxattrat+0x364/0x3a0 fs/xattr.c:713 __do_sys_lsetxattr fs/xattr.c:754 [inline] __se_sys_lsetxattr fs/xattr.c:750 [inline] __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fea2a78f749 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:00007fea2b5eb038 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd RAX: ffffffffffffffda RBX: 00007fea2a9e5fa0 RCX: 00007fea2a78f749 RDX: 0000200000000100 RSI: 00002000000000c0 RDI: 0000200000000280 RBP: 00007fea2a813f91 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fea2a9e6038 R14: 00007fea2a9e5fa0 R15: 00007ffee92390d8