INFO: task syz.0.16:4369 blocked for more than 143 seconds.
      Not tainted 5.15.187-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.0.16        state:D stack:26056 pid: 4369 ppid:  4300 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 d_wait_lookup+0x18b/0x250 fs/dcache.c:2569
 d_alloc_parallel+0xa01/0x12d0 fs/dcache.c:2651
 lookup_open fs/namei.c:3387 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x935/0x2f30 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7fdf594929
RSP: 002b:00007f7fde804038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f7fdf7bbfa0 RCX: 00007f7fdf594929
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007f7fdf616b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7fdf7bbfa0 R15: 00007ffd2d7231b8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
 #0: ffffffff8c11c2e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30
1 lock held by kswapd0/254:
2 locks held by kworker/u4:4/1510:
2 locks held by getty/3951:
 #0: ffff88802bfab098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:252
 #1: ffffc900025ce2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x5ba/0x1a30 drivers/tty/n_tty.c:2158
1 lock held by syz.0.16/4369:
 #0: ffff88806e7e8188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806e7e8188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: open_last_lookups fs/namei.c:3531 [inline]
 #0: ffff88806e7e8188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: path_openat+0x7e4/0x2f30 fs/namei.c:3739
1 lock held by syz.0.16/4370:
2 locks held by syz.1.17/4393:
1 lock held by syz.1.17/4394:
 #0: ffff888045e60188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888045e60188 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.2.18/4415:
1 lock held by syz.2.18/4416:
 #0: ffff888045e606d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888045e606d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.3.19/4443:
1 lock held by syz.3.19/4444:
 #0: ffff88806e7e86d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806e7e86d0 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.4.20/4474:
1 lock held by syz.4.20/4475:
 #0: ffff888045e60c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888045e60c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.5.21/4503:
1 lock held by syz.5.21/4504:
 #0: ffff88806e7e8c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806e7e8c18 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.6.22/4540:
1 lock held by syz.6.22/4541:
 #0: ffff888045e61160 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff888045e61160 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
1 lock held by syz.7.23/4573:
1 lock held by syz.7.23/4574:
 #0: ffff88806e7e9160 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: inode_lock_shared include/linux/fs.h:797 [inline]
 #0: ffff88806e7e9160 (&type->i_mutex_dir_key#8){.+.+}-{3:3}, at: lookup_slow+0x46/0x70 fs/namei.c:1679
2 locks held by syz-executor/4576:
 #0: ffffffff8d237548 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:72 [inline]
 #0: ffffffff8d237548 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x974/0xe60 net/core/rtnetlink.c:5647
 #1: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:290 [inline]
 #1: ffffffff8c120d68 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x347/0x6b0 kernel/rcu/tree_exp.h:845

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

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.15.187-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
 watchdog+0xe0f/0xe50 kernel/hung_task.c:369
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4503 Comm: syz.5.21 Not tainted 5.15.187-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:lock_release+0x6/0x870 kernel/locking/lockdep.c:5631
Code: c1 03 38 c1 0f 8c c1 f8 ff ff 48 89 df e8 12 d5 60 00 e9 b4 f8 ff ff bb 2f 00 00 00 e9 ca f8 ff ff 0f 1f 00 55 48 89 e5 41 57 <41> 56 41 55 41 54 53 48 83 e4 e0 48 81 ec e0 00 00 00 48 89 74 24
RSP: 0018:ffffc90003c5f4d8 EFLAGS: 00000287
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 5ee43c1b0c0f7600
RDX: 0000000000000000 RSI: ffffffff81bcf290 RDI: ffffffff8c11c2e0
RBP: ffffc90003c5f4e0 R08: dffffc0000000000 R09: fffffbfff1ff7619
R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: 0000000000000001
R13: ffffea0005b0df40 R14: 0000000000000000 R15: ffffc90003c5f558
FS:  00007ff97aeb46c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f9e045e4e9c CR3: 000000007b339000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 rcu_read_unlock include/linux/rcupdate.h:772 [inline]
 percpu_ref_get_many include/linux/percpu-refcount.h:209 [inline]
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 obj_cgroup_get include/linux/memcontrol.h:805 [inline]
 memcg_slab_post_alloc_hook mm/slab.h:320 [inline]
 slab_post_alloc_hook+0x240/0x380 mm/slab.h:526
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
 kmem_cache_zalloc include/linux/slab.h:725 [inline]
 alloc_buffer_head+0x21/0x100 fs/buffer.c:3311
 alloc_page_buffers+0x341/0x600 fs/buffer.c:832
 create_empty_buffers+0x3a/0x6d0 fs/buffer.c:1562
 create_page_buffers+0x1c4/0x320 fs/buffer.c:1679
 block_read_full_page+0xe5/0xd10 fs/buffer.c:2270
 do_read_cache_page+0x8a1/0x1030 mm/filemap.c:-1
 read_mapping_page include/linux/pagemap.h:515 [inline]
 dir_get_page fs/sysv/dir.c:58 [inline]
 sysv_find_entry+0x186/0x5e0 fs/sysv/dir.c:146
 sysv_inode_by_name+0x2f/0x310 fs/sysv/dir.c:360
 sysv_lookup+0x66/0xe0 fs/sysv/namei.c:38
 lookup_open fs/namei.c:3440 [inline]
 open_last_lookups fs/namei.c:3532 [inline]
 path_openat+0x1003/0x2f30 fs/namei.c:3739
 do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
 do_sys_openat2+0x142/0x4a0 fs/open.c:1253
 do_sys_open fs/open.c:1269 [inline]
 __do_sys_openat fs/open.c:1285 [inline]
 __se_sys_openat fs/open.c:1280 [inline]
 __x64_sys_openat+0x135/0x160 fs/open.c:1280
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7ff97bc44929
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff97aeb4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ff97be6bfa0 RCX: 00007ff97bc44929
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007ff97bcc6b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007ff97be6bfa0 R15: 00007ffc3bf13a48
 </TASK>