INFO: task syz.6.302:7720 blocked for more than 143 seconds.
      Not tainted syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.6.302       state:D stack:28872 pid:7720  tgid:7698  ppid:6938   task_flags:0x400040 flags:0x00080002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5254 [inline]
 __schedule+0x17c4/0x4d60 kernel/sched/core.c:6862
 __schedule_loop kernel/sched/core.c:6944 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6959
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7016
 rwsem_down_read_slowpath+0x5fd/0x8f0 kernel/locking/rwsem.c:1086
 __down_read_common kernel/locking/rwsem.c:1261 [inline]
 __down_read kernel/locking/rwsem.c:1274 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1539
 inode_lock_shared include/linux/fs.h:995 [inline]
 lookup_slow+0x46/0x70 fs/namei.c:1832
 walk_component+0x2d2/0x400 fs/namei.c:2151
 lookup_last fs/namei.c:2652 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2676
 filename_lookup+0x212/0x570 fs/namei.c:2705
 do_linkat+0x120/0x560 fs/namei.c:4991
 __do_sys_link fs/namei.c:5045 [inline]
 __se_sys_link fs/namei.c:5043 [inline]
 __x64_sys_link+0x82/0x90 fs/namei.c:5043
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fac0918efc9
RSP: 002b:00007fac0a071038 EFLAGS: 00000246 ORIG_RAX: 0000000000000056
RAX: ffffffffffffffda RBX: 00007fac093e6090 RCX: 00007fac0918efc9
RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000200000000040
RBP: 00007fac09211f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fac093e6128 R14: 00007fac093e6090 R15: 00007ffed9db2ef8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline]
 #0: ffffffff8df3d5a0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
1 lock held by klogd/5189:
 #0: ffff8880b863a018 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xad/0x140 kernel/sched/core.c:646
2 locks held by getty/5592:
 #0: ffff888033c820a0 (&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+0x43e/0x1400 drivers/tty/n_tty.c:2222
4 locks held by kworker/u8:8/5991:
 #0: ffff88801daed948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3238 [inline]
 #0: ffff88801daed948 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3346
 #1: ffffc90004867ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3239 [inline]
 #1: ffffc90004867ba0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3346
 #2: ffff88807be8c0e0 (&type->s_umount_key#69){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:562
 #3: ffff88805761d430 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:108
4 locks held by syz.6.302/7700:
1 lock held by syz.6.302/7720:
 #0: ffff88805761d7e0 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:995 [inline]
 #0: ffff88805761d7e0 (&type->i_mutex_dir_key#20){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1832
2 locks held by syz-executor/7957:
 #0: ffff888055faa0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff888055faa0e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff888055faa0e0 (&type->s_umount_key#71){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:505
 #1: ffffffff8df42f00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
2 locks held by syz.2.682/9499:
 #0: ffff88807be8c0e0 (&type->s_umount_key#69){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff88807be8c0e0 (&type->s_umount_key#69){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff888024b52820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff888024b52820 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2871
1 lock held by syz.3.755/10092:
 #0: ffffffff8df42f00 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3820
1 lock held by sed/10106:

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

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 10/02/2025
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:337 [inline]
 watchdog+0xfa9/0xff0 kernel/hung_task.c:500
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 10 Comm: kworker/0:1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events free_obj_work
RIP: 0010:lock_acquire+0x11b/0x360 kernel/locking/lockdep.c:5868
Code: 4c 89 7c 24 08 41 f7 c7 00 02 00 00 41 0f 94 c1 4c 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 <e8> e0 02 00 00 48 83 c4 28 48 c7 c7 2f 0b 96 8d e8 b0 07 ac 09 b8
RSP: 0018:ffffc900000f73d0 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8df3d5a0
RBP: ffffffff81738f15 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc900000f75b8 R11: ffffffff81ac55d0 R12: 0000000000000002
R13: ffffffff8df3d5a0 R14: 0000000000000000 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff888125f22000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055f8ef1da950 CR3: 000000007f6b0000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
 unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2539 [inline]
 slab_free mm/slub.c:6630 [inline]
 kmem_cache_free+0x19b/0x690 mm/slub.c:6740
 free_object_list lib/debugobjects.c:326 [inline]
 free_obj_work+0x377/0x4a0 lib/debugobjects.c:513
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>