INFO: task syz.4.66:6628 blocked for more than 143 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.66        state:D stack:26696 pid:6628  tgid:6605  ppid:5836   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write+0x1ab/0x1f0 kernel/locking/rwsem.c:1578
 inode_lock include/linux/fs.h:869 [inline]
 open_last_lookups fs/namei.c:3813 [inline]
 path_openat+0x8da/0x3830 fs/namei.c:4052
 do_filp_open+0x1fa/0x410 fs/namei.c:4082
 do_sys_openat2+0x121/0x1c0 fs/open.c:1437
 do_sys_open fs/open.c:1452 [inline]
 __do_sys_openat fs/open.c:1468 [inline]
 __se_sys_openat fs/open.c:1463 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1463
 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: 0033:0x7f1dd318e929
RSP: 002b:00007f1dd3fff038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f1dd33b6080 RCX: 00007f1dd318e929
RDX: 000000000000275a RSI: 0000200000000000 RDI: ffffffffffffff9c
RBP: 00007f1dd3210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1dd33b6080 R15: 00007ffd8f298948
 </TASK>
INFO: task syz.4.66:6636 blocked for more than 144 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.66        state:D stack:25128 pid:6636  tgid:6605  ppid:5836   task_flags:0x400140 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 rwsem_down_write_slowpath+0xbec/0x1030 kernel/locking/rwsem.c:1176
 __down_write_common kernel/locking/rwsem.c:1304 [inline]
 __down_write kernel/locking/rwsem.c:1313 [inline]
 down_write_nested+0x1b5/0x200 kernel/locking/rwsem.c:1694
 inode_lock_nested include/linux/fs.h:914 [inline]
 do_rmdir+0x1b2/0x630 fs/namei.c:4517
 __do_sys_rmdir fs/namei.c:4544 [inline]
 __se_sys_rmdir fs/namei.c:4542 [inline]
 __x64_sys_rmdir+0x47/0x50 fs/namei.c:4542
 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: 0033:0x7f1dd318e929
RSP: 002b:00007f1dd3fbd038 EFLAGS: 00000246 ORIG_RAX: 0000000000000054
RAX: ffffffffffffffda RBX: 00007f1dd33b6240 RCX: 00007f1dd318e929
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007f1dd3210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f1dd33b6240 R15: 00007ffd8f298948
 </TASK>
INFO: task syz.4.66:6646 blocked for more than 145 seconds.
      Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.4.66        state:D stack:28904 pid:6646  tgid:6605  ppid:5836   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785
 __schedule_loop kernel/sched/core.c:6863 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6878
 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6935
 rwsem_down_read_slowpath+0x552/0x880 kernel/locking/rwsem.c:1084
 __down_read_common kernel/locking/rwsem.c:1248 [inline]
 __down_read kernel/locking/rwsem.c:1261 [inline]
 down_read+0x98/0x2e0 kernel/locking/rwsem.c:1526
 inode_lock_shared include/linux/fs.h:884 [inline]
 lookup_slow+0x46/0x70 fs/namei.c:1833
 walk_component+0x2d2/0x400 fs/namei.c:2138
 lookup_last fs/namei.c:2639 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2663
 filename_lookup+0x212/0x570 fs/namei.c:2692
 user_path_at+0x3a/0x60 fs/namei.c:3136
 do_mount fs/namespace.c:4236 [inline]
 __do_sys_mount fs/namespace.c:4450 [inline]
 __se_sys_mount+0x2d3/0x410 fs/namespace.c:4427
 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: 0033:0x7f1dd318e929
RSP: 002b:00007f1dd3f7b038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f1dd33b6400 RCX: 00007f1dd318e929
RDX: 0000200000000340 RSI: 0000200000000300 RDI: 0000000000000000
RBP: 00007f1dd3210b39 R08: 0000200000000380 R09: 0000000000000000
R10: 0000000000010000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f1dd33b6400 R15: 00007ffd8f298948
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/31:
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8e13ee20 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6770
4 locks held by kworker/u8:3/49:
 #0: ffff888142edc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline]
 #0: ffff888142edc148 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3321
 #1: ffffc90000b97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline]
 #1: ffffc90000b97bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3321
 #2: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff8880592ed4c0 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
2 locks held by kworker/u8:4/77:
 #0: ffff8880b8639e18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:606
 #1: ffff8880b8623f08 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x39e/0x6d0 kernel/sched/psi.c:987
2 locks held by getty/5596:
 #0: ffff8880350620a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc9000333b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x43e/0x1400 drivers/tty/n_tty.c:2222
1 lock held by syz-executor/5841:
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
4 locks held by syz.4.66/6606:
2 locks held by syz.4.66/6628:
 #0: ffff888028f88428 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff8880592ed870 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:869 [inline]
 #1: ffff8880592ed870 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: open_last_lookups fs/namei.c:3813 [inline]
 #1: ffff8880592ed870 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: path_openat+0x8da/0x3830 fs/namei.c:4052
2 locks held by syz.4.66/6636:
 #0: ffff888028f88428 (sb_writers#24){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff8880592ed870 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
 #1: ffff8880592ed870 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: do_rmdir+0x1b2/0x630 fs/namei.c:4517
1 lock held by syz.4.66/6646:
 #0: ffff8880592ed870 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline]
 #0: ffff8880592ed870 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1833
1 lock held by syz-executor/6828:
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: exp_funnel_lock kernel/rcu/tree_exp.h:336 [inline]
 #0: ffffffff8e144938 (rcu_state.exp_mutex){+.+.}-{4:4}, at: synchronize_rcu_expedited+0x3b9/0x730 kernel/rcu/tree_exp.h:998
2 locks held by syz-executor/7366:
 #0: ffff8880777fc0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock fs/super.c:57 [inline]
 #0: ffff8880777fc0e0 (&type->s_umount_key#65){++++}-{4:4}, at: __super_lock_excl fs/super.c:72 [inline]
 #0: ffff8880777fc0e0 (&type->s_umount_key#65){++++}-{4:4}, at: deactivate_super+0xa9/0xe0 fs/super.c:506
 #1: ffffffff8e144800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x570 kernel/rcu/tree.c:3786
2 locks held by syz.2.250/8402:
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.2.250/8405:
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
2 locks held by syz.2.250/8406:
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff888028f880e0 (&type->s_umount_key#71){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8880252e47d0 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19f/0xa10 fs/fs-writeback.c:2831
5 locks held by syz-executor/8536:
 #0: ffff88807904a428 (sb_writers#9){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:3096 [inline]
 #0: ffff88807904a428 (sb_writers#9){.+.+}-{0:0}, at: vfs_write+0x211/0xa90 fs/read_write.c:682
 #1: ffff88807becec88 (&of->mutex){+.+.}-{4:4}, at: kernfs_fop_write_iter+0x1e0/0x4f0 fs/kernfs/file.c:325
 #2: ffffffff8e176608 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_lock include/linux/cgroup.h:387 [inline]
 #2: ffffffff8e176608 (cgroup_mutex){+.+.}-{4:4}, at: cgroup_kn_lock_live+0x13c/0x230 kernel/cgroup/cgroup.c:1686
 #3: ffffffff8dfd6f90 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2480 [inline]
 #3: ffffffff8dfd6f90 (cpu_hotplug_lock){++++}-{0:0}, at: cgroup_procs_write_start+0x186/0x600 kernel/cgroup/cgroup.c:2984
 #4: ffffffff8e1768b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2482 [inline]
 #4: ffffffff8e1768b0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x19c/0x600 kernel/cgroup/cgroup.c:2984

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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:158 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline]
 watchdog+0xfee/0x1030 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: 5888 Comm: udevd Not tainted 6.16.0-rc4-syzkaller-00123-g4c06e63b9203 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:bpf_lsm_inode_permission+0x4/0x20 include/linux/lsm_hook_defs.h:142
Code: c0 c3 cc cc cc cc cc 66 66 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 <e8> e7 1d d3 ff 31 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e 0f 1f
RSP: 0018:ffffc900042df8b8 EFLAGS: 00000293
RAX: ffffffff84725ed1 RBX: 0000000000000001 RCX: ffff888059ba1e00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff888078581e30
RBP: 0000000000000000 R08: ffffc900042df7e0 R09: 0000000000000000
R10: ffffc900042df800 R11: fffff5200085bf05 R12: ffffc900042dfa80
R13: ffffc900042dfab0 R14: ffff888078581e30 R15: 0000000000000000
FS:  00007f4e02f5e880(0000) GS:ffff888125d51000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055763c625df0 CR3: 0000000032494000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 security_inode_permission+0x125/0x310 security/security.c:2324
 may_lookup fs/namei.c:1845 [inline]
 link_path_walk+0x232/0xea0 fs/namei.c:2454
 path_lookupat+0x97/0x430 fs/namei.c:2662
 filename_lookup+0x212/0x570 fs/namei.c:2692
 vfs_statx+0xf8/0x550 fs/stat.c:353
 vfs_fstatat+0x118/0x170 fs/stat.c:375
 __do_sys_newfstatat fs/stat.c:542 [inline]
 __se_sys_newfstatat fs/stat.c:536 [inline]
 __x64_sys_newfstatat+0x116/0x190 fs/stat.c:536
 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: 0033:0x7f4e02911b0a
Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
RSP: 002b:00007ffcd21bdf28 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffcd21be820 RCX: 00007f4e02911b0a
RDX: 00007ffcd21bdf90 RSI: 00007ffcd21be420 RDI: 00000000ffffff9c
RBP: 00007ffcd21be420 R08: feda080000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000055763c572160
R13: 000055763c577430 R14: 000055763c562538 R15: 0000557614a69bcc
 </TASK>