INFO: task kworker/1:6:5939 blocked for more than 143 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:6     state:D stack:23720 pid:5939  tgid:5939  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events_long flush_mdb
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1585/0x5340 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7004
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93
 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120
 lock_buffer include/linux/buffer_head.h:432 [inline]
 hfs_mdb_commit+0x115/0x1150 fs/hfs/mdb.c:294
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 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>
INFO: task syz.2.173:6677 blocked for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.173       state:D stack:25152 pid:6677  tgid:6672  ppid:5816   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1585/0x5340 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7004
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831
 bit_wait_io+0x11/0xd0 kernel/sched/wait_bit.c:250
 __wait_on_bit_lock+0xec/0x4e0 kernel/sched/wait_bit.c:93
 out_of_line_wait_on_bit_lock+0x13b/0x190 kernel/sched/wait_bit.c:120
 wait_on_bit_lock_io include/linux/wait_bit.h:221 [inline]
 __lock_buffer fs/buffer.c:72 [inline]
 lock_buffer include/linux/buffer_head.h:432 [inline]
 __block_write_full_folio+0x54f/0xe10 fs/buffer.c:1908
 blkdev_writepages+0xef/0x1b0 block/fops.c:487
 do_writepages+0x32e/0x550 mm/page-writeback.c:2554
 filemap_writeback mm/filemap.c:387 [inline]
 filemap_fdatawrite_range mm/filemap.c:412 [inline]
 filemap_write_and_wait_range+0x335/0x3f0 mm/filemap.c:684
 hfs_file_fsync+0x113/0x140 fs/hfs/inode.c:712
 generic_write_sync include/linux/fs.h:2640 [inline]
 generic_file_write_iter+0x37e/0x680 mm/filemap.c:4461
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x61d/0xb90 fs/read_write.c:688
 ksys_write+0x150/0x270 fs/read_write.c:740
 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: 0033:0x7f030339c629
RSP: 002b:00007f0304260028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f0303615fa0 RCX: 00007f030339c629
RDX: 00000000000000a0 RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007f0303432b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0303616038 R14: 00007f0303615fa0 R15: 00007ffe953e2f88
 </TASK>
INFO: task syz.2.173:6680 blocked for more than 145 seconds.
      Tainted: G             L      syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.2.173       state:D stack:27296 pid:6680  tgid:6672  ppid:5816   task_flags:0x400140 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5295 [inline]
 __schedule+0x1585/0x5340 kernel/sched/core.c:6907
 __schedule_loop kernel/sched/core.c:6989 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7004
 io_schedule+0x7f/0xd0 kernel/sched/core.c:7831
 folio_wait_bit_common+0x6d8/0xbc0 mm/filemap.c:1323
 folio_lock include/linux/pagemap.h:1170 [inline]
 __find_get_block_slow fs/buffer.c:206 [inline]
 find_get_block_common+0x34f/0xe10 fs/buffer.c:1406
 bdev_getblk+0x53/0x6e0 include/linux/gfp.h:-1
 __bread_gfp+0x89/0x3b0 fs/buffer.c:1513
 sb_bread include/linux/buffer_head.h:346 [inline]
 hfs_mdb_commit+0xc63/0x1150 fs/hfs/mdb.c:344
 hfs_sync_fs+0x1d/0x30 fs/hfs/super.c:38
 sync_filesystem+0xee/0x230 fs/sync.c:56
 hfs_reconfigure+0x66/0x270 fs/hfs/super.c:122
 reconfigure_super+0x227/0x8a0 fs/super.c:1080
 do_remount fs/namespace.c:3388 [inline]
 path_mount+0xdc5/0x10e0 fs/namespace.c:4138
 do_mount fs/namespace.c:4159 [inline]
 __do_sys_mount fs/namespace.c:4348 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4325
 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: 0033:0x7f030339d8ca
RSP: 002b:00007f030423ee58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f030423eee0 RCX: 00007f030339d8ca
RDX: 0000200000000180 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 0000200000000180 R08: 00007f030423eee0 R09: 00000000018424bc
R10: 00000000018424bc R11: 0000000000000246 R12: 0000200000000000
R13: 00007f030423eea0 R14: 0000000000000000 R15: 00002000000003c0
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline]
 #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
3 locks held by kworker/u8:3/49:
 #0: ffff88801fea7948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88801fea7948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90000b97c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90000b97c40 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
 #2: ffff88801b6f20e0 (&type->s_umount_key#41){.+.+}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:565
2 locks held by getty/5575:
 #0: ffff8880369350a0 (&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
2 locks held by kworker/1:6/5939:
 #0: ffff88813fe0ed48 ((wq_completion)events_long){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88813fe0ed48 ((wq_completion)events_long){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc900040e7c40 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc900040e7c40 ((work_completion)(&(&sbi->mdb_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
2 locks held by kworker/u8:10/6000:
 #0: ffff88801e70e948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88801e70e948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90004477c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90004477c40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
3 locks held by syz.2.173/6677:
 #0: ffff888020b09438 (&f->f_pos_lock){+.+.}-{4:4}, at: fdget_pos+0x246/0x320 fs/file.c:1261
 #1: ffff888031ffe420 (sb_writers#23){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2710 [inline]
 #1: ffff888031ffe420 (sb_writers#23){.+.+}-{0:0}, at: vfs_write+0x227/0xb90 fs/read_write.c:684
 #2: ffff88804502a9a0 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline]
 #2: ffff88804502a9a0 (&sb->s_type->i_mutex_key#38){+.+.}-{4:4}, at: hfs_file_fsync+0x9a/0x140 fs/hfs/inode.c:703
1 lock held by syz.2.173/6680:
 #0: ffff888031ffe0e0 (&type->s_umount_key#65){+.+.}-{4:4}, at: do_remount fs/namespace.c:3385 [inline]
 #0: ffff888031ffe0e0 (&type->s_umount_key#65){+.+.}-{4:4}, at: path_mount+0xd7d/0x10e0 fs/namespace.c:4138
1 lock held by syz-executor/6922:
 #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:311 [inline]
 #0: ffffffff8e766578 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x2d0/0x770 kernel/rcu/tree_exp.h:961
2 locks held by kworker/u8:16/7122:
 #0: ffff88801e70e948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3250 [inline]
 #0: ffff88801e70e948 ((wq_completion)iou_exit){+.+.}-{0:0}, at: process_scheduled_works+0x9ea/0x1830 kernel/workqueue.c:3358
 #1: ffffc90004d2fc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3251 [inline]
 #1: ffffc90004d2fc40 ((work_completion)(&ctx->exit_work)){+.+.}-{0:0}, at: process_scheduled_works+0xa25/0x1830 kernel/workqueue.c:3358
3 locks held by syz.0.561/8511:
3 locks held by dhcpcd-run-hook/8536:
 #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655
 #1: ffff8880b8724588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933
 #2: ffff88803adcb378 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:341 [inline]
 #2: ffff88803adcb378 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_pte_fault mm/memory.c:6316 [inline]
 #2: ffff88803adcb378 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __handle_mm_fault mm/memory.c:6446 [inline]
 #2: ffff88803adcb378 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: handle_mm_fault+0x146c/0x3310 mm/memory.c:6615
1 lock held by sed/8539:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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:467
 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: 7130 Comm: kworker/u8:19 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:rcu_is_watching+0x0/0xb0 kernel/rcu/tree.c:748
Code: c7 c7 60 59 76 8e e8 4f b4 3f 03 eb cc 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 41 57 41 56 53 65 ff 05 a0 fa 70 11 e8 0b 67 02 0a 89
RSP: 0018:ffffc90004b1f4d0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff90a4e301 RCX: ffff88807ee08000
RDX: ffffc90004b1f601 RSI: dffffc0000000000 RDI: ffffc90004b1f610
RBP: dffffc0000000000 R08: ffffc90004b1f690 R09: ffffc90004b1f658
R10: dffffc0000000000 R11: fffff52000963ecd R12: ffffc90004b1f6a0
R13: ffffc90004b18000 R14: ffffc90004b1f608 R15: ffffffff81767a45
FS:  0000000000000000(0000) GS:ffff888125566000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005599dc807178 CR3: 00000000273b7000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:879 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0x1a66/0x23c0 arch/x86/kernel/unwind_orc.c:695
 __unwind_start+0x5b8/0x760 arch/x86/kernel/unwind_orc.c:773
 unwind_start arch/x86/include/asm/unwind.h:64 [inline]
 arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2687 [inline]
 slab_free mm/slub.c:6124 [inline]
 kmem_cache_free+0x187/0x630 mm/slub.c:6254
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:892 [inline]
 nsim_dev_trap_report_work+0x7cf/0xb80 drivers/net/netdevsim/dev.c:922
 process_one_work kernel/workqueue.c:3275 [inline]
 process_scheduled_works+0xb02/0x1830 kernel/workqueue.c:3358
 worker_thread+0xa50/0xfc0 kernel/workqueue.c:3439
 kthread+0x388/0x470 kernel/kthread.c:467
 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>