syzbot

INFO: task kworker/u8:11:1171 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/u8:11   state:D
 stack:22080 pid:1171  tgid:1171  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: writeback wb_workfn
 (flush-7:0)

Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5298 [inline]
 __schedule+0x15dd/0x52d0 kernel/sched/core.c:6911
 __schedule_loop kernel/sched/core.c:6993 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7008
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7065
 __mutex_lock_common kernel/locking/mutex.c:692 [inline]
 __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776
 hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
 hfsplus_cat_write_inode+0x22b/0x8e0 fs/hfsplus/inode.c:650
 write_inode fs/fs-writeback.c:1582 [inline]
 __writeback_single_inode+0x75a/0x11a0 fs/fs-writeback.c:1825
 writeback_sb_inodes+0x992/0x1a20 fs/fs-writeback.c:2054
 __writeback_inodes_wb+0x111/0x240 fs/fs-writeback.c:2130
 wb_writeback+0x46a/0xb70 fs/fs-writeback.c:2241
 wb_check_old_data_flush fs/fs-writeback.c:2345 [inline]
 wb_do_writeback fs/fs-writeback.c:2398 [inline]
 wb_workfn+0xb4c/0xf50 fs/fs-writeback.c:2426
 process_one_work kernel/workqueue.c:3276 [inline]
 process_scheduled_works+0xb6e/0x18c0 kernel/workqueue.c:3359
 worker_thread+0xa53/0xfc0 kernel/workqueue.c:3440
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 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: 
ffffffff8e75e5a0
 (
rcu_read_lock
){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
4 locks held by kworker/u8:11/1171:
 #0: 
ffff88801febf948
 (
(wq_completion)writeback
){+.+.}-{0:0}
, at: process_one_work kernel/workqueue.c:3251 [inline]
, at: process_scheduled_works+0xa52/0x18c0 kernel/workqueue.c:3359
 #1: ffffc90004a2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3252 [inline]
 #1: ffffc90004a2fc40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa8d/0x18c0 kernel/workqueue.c:3359
 #2: ffff8880784ea0e0 (&type->s_umount_key#43){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
 #3: 
ffff8880764560b0
 (
&tree->tree_lock
){+.+.}-{4:4}
, at: hfsplus_find_init+0x168/0x2d0 fs/hfsplus/bfind.c:28
2 locks held by getty/5578:
 #0: 
ffff88803297e0a0
 (
&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+0x45c/0x13c0 drivers/tty/n_tty.c:2211
9 locks held by syz-executor108/5816:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113
 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:161 [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+0xfd9/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 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: 5816 Comm: syz-executor108 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:desc_read+0x23f/0x3f0 kernel/printk/printk_ringbuffer.c:500
Code: 00 fc ff df 48 8b 5c 24 18 4c 8b 6c 24 10 4d 01 f5 48 83 7c 24 08 00 74 7e e8 8d c7 1f 00 4c 89 e8 48 c1 e8 03 42 80 3c 38 00 <74> 08 4c 89 ef e8 67 16 8a 00 4d 8b 75 00 48 8b 7c 24 08 48 89 f8
RSP: 0018:ffffc900037468f8 EFLAGS: 00000246
RAX: 1ffffffff1cda8ff RBX: 0000000000000000 RCX: ffff88807d251e80
RDX: 0000000000000000 RSI: ffffffff8e652a50 RDI: ffffc90003746a58
RBP: ffffffff8e652a38 R08: ffffc90003746a57 R09: 1ffff920006e8d4a
R10: dffffc0000000000 R11: fffff520006e8d4b R12: ffffc90003746a40
R13: ffffffff8e6d47f8 R14: 0000000000060038 R15: dffffc0000000000
FS:  00005555853c7400(0000) GS:ffff888125554000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffddc7fdf52 CR3: 0000000072e42000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 desc_read_finalized_seq kernel/printk/printk_ringbuffer.c:1931 [inline]
 prb_read kernel/printk/printk_ringbuffer.c:1979 [inline]
 _prb_read_valid+0x27a/0xa80 kernel/printk/printk_ringbuffer.c:2170
 prb_read_valid+0x3c/0x60 kernel/printk/printk_ringbuffer.c:2242
 printk_get_next_message+0x18b/0x880 kernel/printk/printk.c:3052
 console_emit_next_record kernel/printk/printk.c:3137 [inline]
 console_flush_one_record kernel/printk/printk.c:3269 [inline]
 console_flush_all+0x501/0xb20 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 hfsplus_bnode_read_u16 fs/hfsplus/bnode.c:60 [inline]
 hfsplus_bnode_dump+0x189/0xa40 fs/hfsplus/bnode.c:362
 hfsplus_brec_remove+0x617/0x700 fs/hfsplus/brec.c:229
 __hfsplus_delete_attr+0x1e0/0x380 fs/hfsplus/attributes.c:325
 hfsplus_replace_attr+0x1ff/0x3d0 fs/hfsplus/attributes.c:460
 __hfsplus_setxattr+0x3a8/0x2610 fs/hfsplus/xattr.c:355
 hfsplus_setxattr+0x124/0x340 fs/hfsplus/xattr.c:461
 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+0x163/0x360 fs/xattr.c:321
 do_setxattr fs/xattr.c:636 [inline]
 filename_setxattr+0x296/0x630 fs/xattr.c:664
 path_setxattrat+0x3eb/0x440 fs/xattr.c:708
 __do_sys_lsetxattr fs/xattr.c:749 [inline]
 __se_sys_lsetxattr fs/xattr.c:745 [inline]
 __x64_sys_lsetxattr+0xbf/0xe0 fs/xattr.c:745
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f363325a8e9
Code: c0 79 93 eb d5 48 8d 7c 1d 00 eb 99 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 d8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc52f6b738 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 0000200000000000 RCX: 00007f363325a8e9
RDX: 0000200000000880 RSI: 00002000000000c0 RDI: 0000200000000280
RBP: 0031656c69662f2e R08: 0000000000000000 R09: 00005555853c8560
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000200000000840
R13: 0072657070752e79 R14: 0000200000000940 R15: 00007f36332ba04b
 </TASK>
INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 3.520 msecs