INFO: task kworker/u4:0:9 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/u4:0 state:D stack:25304 pid: 9 ppid: 2 flags:0x00004000 Workqueue: writeback wb_workfn (flush-7:0) Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 hfsplus_cat_write_inode+0x238/0x890 fs/hfsplus/inode.c:612 write_inode fs/fs-writeback.c:1505 [inline] __writeback_single_inode+0x6c3/0xda0 fs/fs-writeback.c:1715 writeback_sb_inodes+0xa4e/0x1680 fs/fs-writeback.c:1940 __writeback_inodes_wb+0x12a/0x3f0 fs/fs-writeback.c:2011 wb_writeback+0x46f/0xbe0 fs/fs-writeback.c:2116 wb_check_background_flush fs/fs-writeback.c:2182 [inline] wb_do_writeback fs/fs-writeback.c:2270 [inline] wb_workfn+0xbd6/0xf20 fs/fs-writeback.c:2298 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 INFO: task kworker/1:5:4205 blocked for more than 144 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:kworker/1:5 state:D stack:25232 pid: 4205 ppid: 2 flags:0x00004000 Workqueue: events_long delayed_sync_fs Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6537 __mutex_lock_common+0xcfc/0x2400 kernel/locking/mutex.c:669 __mutex_lock kernel/locking/mutex.c:729 [inline] mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:743 hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223 delayed_sync_fs+0x94/0xe0 fs/hfsplus/super.c:271 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Showing all locks held in the system: 4 locks held by kworker/u4:0/9: #0: ffff8881419f8138 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc90000ce7d00 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff8880793520e0 (&type->s_umount_key#51){.+.+}-{3:3}, at: trylock_super+0x1c/0xf0 fs/super.c:418 #3: ffff888078c960b0 (&tree->tree_lock){+.+.}-{3:3}, at: hfsplus_find_init+0x150/0x1c0 fs/hfsplus/bfind.c:28 1 lock held by khungtaskd/27: #0: ffffffff8c31eaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 2 locks held by getty/3951: #0: ffff88807f00a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252 #1: ffffc900025e62e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5df/0x1a70 drivers/tty/n_tty.c:2158 3 locks held by kworker/1:5/4205: #0: ffff888016c71138 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work+0x761/0x1010 kernel/workqueue.c:-1 #1: ffffc900031afd00 ((work_completion)(&(&sbi->sync_work)->work)){+.+.}-{0:0}, at: process_one_work+0x79f/0x1010 kernel/workqueue.c:2285 #2: ffff88807d2db998 (&sbi->vh_mutex){+.+.}-{3:3}, at: hfsplus_sync_fs+0x262/0x770 fs/hfsplus/super.c:223 10 locks held by syz-executor.0/4586: 1 lock held by syz-executor.0/8316: #0: ffff8880b903a358 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x26/0x140 kernel/sched/core.c:475 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline] watchdog+0xe0f/0xe50 kernel/hung_task.c:369 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4586 Comm: syz-executor.0 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:172 [inline] RIP: 0010:write_comp_data kernel/kcov.c:227 [inline] RIP: 0010:__sanitizer_cov_trace_cmp8+0x1b/0x80 kernel/kcov.c:273 Code: 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 65 48 8b 0d 94 4b 89 7e 65 8b 15 95 4b 89 7e 81 e2 00 01 ff 00 74 11 <81> fa 00 01 00 00 75 57 83 b9 34 16 00 00 00 74 4e 8b 91 10 16 00 RSP: 0018:ffffc90000007e30 EFLAGS: 00000006 RAX: ffffffff816985df RBX: 7fffffffffffffff RCX: ffff88801d889dc0 RDX: 0000000000010000 RSI: 7fffffffffffffff RDI: 000000357834c46b RBP: 0000000000000003 R08: ffffffff8d89dc2f R09: 1ffffffff1b13b85 R10: dffffc0000000000 R11: fffffbfff1b13b86 R12: 000000776f5ae761 R13: dffffc0000000000 R14: ffff8880b902a3a8 R15: 000000357834c46b FS: 00007f57118206c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe527e55988 CR3: 00000000786c9000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ktime_get_update_offsets_now+0x2bf/0x3e0 kernel/time/timekeeping.c:2314 hrtimer_update_base kernel/time/hrtimer.c:621 [inline] hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:console_trylock_spinning+0x301/0x370 kernel/printk/printk.c:1909 Code: 85 db 74 89 e8 50 e7 18 00 fb 31 c0 eb 48 e8 46 e7 18 00 e8 d1 ed 5b 08 48 85 db 74 d1 e8 37 e7 18 00 fb 48 c7 c7 e0 35 31 8c <31> f6 ba 01 00 00 00 31 c9 41 b8 01 00 00 00 45 31 c9 68 0a 3b 60 RSP: 0018:ffffc9000115f300 EFLAGS: 00000293 RAX: ffffffff81603b09 RBX: 0000000000000200 RCX: ffff88801d889dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8c3135e0 RBP: ffffc9000115f3d0 R08: ffffffff901d31ff R09: 1ffffffff203a63f R10: dffffc0000000000 R11: fffffbfff203a640 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffff9200022be60 vprintk_emit+0xa7/0x150 kernel/printk/printk.c:2273 _printk+0xda/0x130 kernel/printk/printk.c:2299 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:62 [inline] hfsplus_bnode_dump+0x39c/0x4d0 fs/hfsplus/bnode.c:369 hfsplus_brec_remove+0x476/0x540 fs/hfsplus/brec.c:229 __hfsplus_delete_attr+0x1dd/0x380 fs/hfsplus/attributes.c:299 hfsplus_delete_all_attrs+0x262/0x3f0 fs/hfsplus/attributes.c:378 hfsplus_delete_cat+0x982/0xd80 fs/hfsplus/catalog.c:425 hfsplus_unlink+0x368/0x7b0 fs/hfsplus/dir.c:385 hfsplus_rename+0xc6/0x1f0 fs/hfsplus/dir.c:547 vfs_rename+0xbe1/0x1100 fs/namei.c:4840 do_renameat2+0x8b7/0xf60 fs/namei.c:4993 __do_sys_rename fs/namei.c:5039 [inline] __se_sys_rename fs/namei.c:5037 [inline] __x64_sys_rename+0x82/0x90 fs/namei.c:5037 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f57124903b9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 d0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f57118200b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000052 RAX: ffffffffffffffda RBX: 00007f57125cdf80 RCX: 00007f57124903b9 RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000020000080 RBP: 00007f57124f1498 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f57125cdf80 R15: 00007ffd827a3078