Message-ID: <688cfb9d.050a0220.f0410.012e.GAE@google.com>
Date: Fri, 01 Aug 2025 10:38:37 -0700
From: syzbot <syzbot+6f9eae7d87e0afb22029@...kaller.appspotmail.com>
To: frank.li@...o.com, glaubitz@...sik.fu-berlin.de, 
	linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org, 
	slava@...eyko.com, syzkaller-bugs@...glegroups.com
Subject: [syzbot] [hfs?] INFO: task hung in hfsplus_find_init (3)

Hello,

syzbot found the following issue on:

HEAD commit:    f2d282e1dfb3 Merge tag 'bitmap-for-6.17' of https://github..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=144faf82580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8b51b56c81c0761d
dashboard link: https://syzkaller.appspot.com/bug?extid=6f9eae7d87e0afb22029
compiler:       Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=124faf82580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=100642a2580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/70f09e088d5c/disk-f2d282e1.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9baa408863b9/vmlinux-f2d282e1.xz
kernel image: https://storage.googleapis.com/syzbot-assets/36063ac42323/bzImage-f2d282e1.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/7fea0d017f73/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6f9eae7d87e0afb22029@...kaller.appspotmail.com

INFO: task kworker/u8:3:49 blocked for more than 143 seconds.
      Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:3    state:D
 stack:21000 pid:49    tgid:49    ppid:2      task_flags:0x4208160 flags:0x00004000
Workqueue: writeback wb_workfn
 (flush-7:0)
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7058
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7115
 __mutex_lock_common kernel/locking/mutex.c:676 [inline]
 __mutex_lock+0x7e3/0x1340 kernel/locking/mutex.c:760
 hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
 hfsplus_cat_write_inode+0x1e6/0x7a0 fs/hfsplus/inode.c:592
 write_inode fs/fs-writeback.c:1525 [inline]
 __writeback_single_inode+0x6f1/0xff0 fs/fs-writeback.c:1745
 writeback_sb_inodes+0x6c7/0x1010 fs/fs-writeback.c:1976
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2047
 wb_writeback+0x44f/0xaf0 fs/fs-writeback.c:2158
 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline]
 wb_do_writeback fs/fs-writeback.c:2315 [inline]
 wb_workfn+0xaef/0xef0 fs/fs-writeback.c:2343
 process_one_work kernel/workqueue.c:3236 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e139e60 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e139e60 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e139e60 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:3/49:
 #0: ffff8881412ee948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff8881412ee948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
 #1: ffffc90000b97bc0 (
(work_completion)(&(&wb->dwork)->work)
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3212 [inline]
, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #2: ffff8880332b00e0
 (
&type->s_umount_key
#42
){.+.+}-{4:4}
, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: 
ffff8880792320b0
 (
&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x15a/0x1d0 fs/hfsplus/bfind.c:28
5 locks held by kworker/u8:4/61:
 #0: 
ffff8880b8739f58
 (
&rq->__lock
){-.-.}-{2:2}
, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:636
 #1: 
ffff8880b8724008
 (
per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
per_cpu_ptr(&psi_seq, cpu)){-.-.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #2: ffffffff8dfd2f50 (cpu_hotplug_lock){++++}-{0:0}, at: static_key_disable+0x12/0x20 kernel/jump_label.c:247
 #3: ffffffff99c6aca8 (
&obj_hash[i].lock
){-.-.}-{2:2}
, at: debug_object_activate+0xbb/0x420 lib/debugobjects.c:818
 #4: 
ffffffff8dfe6308
 (
text_mutex
){+.+.}-{4:4}
, at: arch_jump_label_transform_apply+0x17/0x30 arch/x86/kernel/jump_label.c:145
2 locks held by getty/5605:
 #0: 
ffff88803031a0a0
 (
&tty->ldisc_sem
){++++}-{0:0}
, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: 
ffffc900036c32f0
 (
&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by syz-executor384/5873:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 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]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:470
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5873 Comm: syz-executor384 Not tainted 6.16.0-syzkaller-10355-gf2d282e1dfb3 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kasan_check_range+0xd/0x2c0 mm/kasan/generic.c:188
Code: 0f 0b cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 41 57 41 56 41 55 41 54 <53> b0 01 48 85 f6 0f 84 ba 01 00 00 4c 8d 04 37 49 39 f8 0f 82 82
RSP: 0018:ffffc9000414eb30 EFLAGS: 00000056
RAX: 00000000ffffff01 RBX: ffffffff99dbe400 RCX: ffffffff819df6c1
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000414eba0
RBP: ffffc9000414ec10 R08: ffffffff99dbe403 R09: 1ffffffff33b7c80
R10: dffffc0000000000 R11: fffffbfff33b7c81 R12: ffffffff99dbe410
R13: ffffffff99dbe408 R14: 1ffffffff33b7c82 R15: 1ffffffff33b7c81
FS:  0000555574d53380(0000) GS:ffff888125d5c000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffcbbc35f19 CR3: 00000000714b1000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1301 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
 do_raw_spin_lock+0x121/0x290 kernel/locking/spinlock_debug.c:116
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb3/0xf0 kernel/locking/spinlock.c:162
 uart_port_lock_irqsave include/linux/serial_core.h:717 [inline]
 serial8250_console_write+0x17e/0x1ba0 drivers/tty/serial/8250/8250_port.c:3355
 console_emit_next_record kernel/printk/printk.c:3138 [inline]
 console_flush_all+0x728/0xc40 kernel/printk/printk.c:3226
 __console_flush_and_unlock kernel/printk/printk.c:3285 [inline]
 console_unlock+0xc4/0x270 kernel/printk/printk.c:3325
 vprintk_emit+0x5b7/0x7a0 kernel/printk/printk.c:2450
 _printk+0xcf/0x120 kernel/printk/printk.c:2475
 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:101 [inline]
 hfsplus_bnode_dump+0x322/0x450 fs/hfsplus/bnode.c:403
 hfsplus_brec_remove+0x480/0x550 fs/hfsplus/brec.c:229
 __hfsplus_delete_attr+0x1d4/0x360 fs/hfsplus/attributes.c:299
 hfsplus_delete_attr+0x231/0x2d0 fs/hfsplus/attributes.c:345
 hfsplus_removexattr fs/hfsplus/xattr.c:796 [inline]
 __hfsplus_setxattr+0x768/0x1fe0 fs/hfsplus/xattr.c:279
 hfsplus_setxattr+0x11e/0x180 fs/hfsplus/xattr.c:436
 hfsplus_user_setxattr+0x40/0x60 fs/hfsplus/xattr_user.c:30
 __vfs_removexattr+0x431/0x470 fs/xattr.c:518
 __vfs_removexattr_locked+0x1ed/0x230 fs/xattr.c:553
 vfs_removexattr+0x80/0x1b0 fs/xattr.c:575
 removexattr fs/xattr.c:1023 [inline]
 filename_removexattr fs/xattr.c:1052 [inline]
 path_removexattrat+0x35d/0x690 fs/xattr.c:1088
 __do_sys_removexattr fs/xattr.c:1100 [inline]
 __se_sys_removexattr fs/xattr.c:1097 [inline]
 __x64_sys_removexattr+0x62/0x70 fs/xattr.c:1097
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd613ef9bd9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff6590fb28 EFLAGS: 00000246 ORIG_RAX: 00000000000000c5
RAX: ffffffffffffffda RBX: 0000200000000340 RCX: 00007fd613ef9bd9
RDX: ffffffffffffffb8 RSI: 0000200000000080 RDI: 0000200000000040
RBP: 0000200000000380 R08: 0000555574d544c0 R09: 0000555574d544c0
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007fff6590fd78 R14: 431bde82d7b634db R15: 0000200000000390
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.116 msecs


---
This report is generated by a bot. It may contain errors.
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If the report is already addressed, let syzbot know by replying with:
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If you want to overwrite report's subsystems, reply with:
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