INFO: task syz.3.87:6509 blocked for more than 143 seconds.
      Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.87        state:D stack:26920 pid:6509  tgid:6504  ppid:5836   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
 __rwbase_read_lock+0xbc/0x180 kernel/locking/rwbase_rt.c:114
 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline]
 __down_read kernel/locking/rwsem.c:1451 [inline]
 down_read+0x127/0x1f0 kernel/locking/rwsem.c:1524
 inode_lock_shared include/linux/fs.h:884 [inline]
 lookup_slow+0x46/0x70 fs/namei.c:1824
 walk_component fs/namei.c:2129 [inline]
 link_path_walk+0x935/0xea0 fs/namei.c:2497
 path_lookupat+0x97/0x430 fs/namei.c:2653
 filename_lookup+0x212/0x570 fs/namei.c:2683
 user_path_at+0x3a/0x60 fs/namei.c:3127
 do_fchmodat+0xef/0x200 fs/open.c:695
 __do_sys_fchmodat fs/open.c:716 [inline]
 __se_sys_fchmodat fs/open.c:713 [inline]
 __x64_sys_fchmodat+0x7d/0x90 fs/open.c:713
 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: 0033:0x7fa79f24eb69
RSP: 002b:00007fa79d08d038 EFLAGS: 00000246 ORIG_RAX: 000000000000010c
RAX: ffffffffffffffda RBX: 00007fa79f476080 RCX: 00007fa79f24eb69
RDX: 0000000000000090 RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007fa79f2d1df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa79f476080 R15: 00007ffe423feec8
 </TASK>
INFO: task syz.3.87:6513 blocked for more than 143 seconds.
      Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.87        state:D stack:27624 pid:6513  tgid:6504  ppid:5836   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
 inode_lock_nested include/linux/fs.h:914 [inline]
 filename_create+0x1f8/0x3c0 fs/namei.c:4139
 do_mknodat+0x184/0x4d0 fs/namei.c:4272
 __do_sys_mknod fs/namei.c:4318 [inline]
 __se_sys_mknod fs/namei.c:4316 [inline]
 __x64_sys_mknod+0x8c/0xa0 fs/namei.c:4316
 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: 0033:0x7fa79f24eb69
RSP: 002b:00007fa79d06c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000085
RAX: ffffffffffffffda RBX: 00007fa79f476160 RCX: 00007fa79f24eb69
RDX: 0000000000000707 RSI: 100000000000600d RDI: 0000200000000080
RBP: 00007fa79f2d1df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa79f476160 R15: 00007ffe423feec8
 </TASK>
INFO: task syz.3.87:6514 blocked for more than 143 seconds.
      Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.3.87        state:D stack:26632 pid:6514  tgid:6504  ppid:5836   task_flags:0x400040 flags:0x00004004
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 rt_mutex_schedule+0x77/0xf0 kernel/sched/core.c:7339
 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1647 [inline]
 __rt_mutex_slowlock kernel/locking/rtmutex.c:1721 [inline]
 __rt_mutex_slowlock_locked+0x1e04/0x25e0 kernel/locking/rtmutex.c:1760
 rt_mutex_slowlock+0xb5/0x160 kernel/locking/rtmutex.c:1800
 __rt_mutex_lock kernel/locking/rtmutex.c:1815 [inline]
 rwbase_write_lock+0x14f/0x750 kernel/locking/rwbase_rt.c:244
 inode_lock_nested include/linux/fs.h:914 [inline]
 filename_create+0x1f8/0x3c0 fs/namei.c:4139
 do_symlinkat+0xbc/0x3f0 fs/namei.c:4749
 __do_sys_symlink fs/namei.c:4777 [inline]
 __se_sys_symlink fs/namei.c:4775 [inline]
 __x64_sys_symlink+0x7a/0x90 fs/namei.c:4775
 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: 0033:0x7fa79f24eb69
RSP: 002b:00007fa79cc49038 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007fa79f476240 RCX: 00007fa79f24eb69
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 00002000000005c0
RBP: 00007fa79f2d1df1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa79f476240 R15: 00007ffe423feec8
 </TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/38:
 #0: ffffffff8d9a8b00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8d9a8b00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline]
 #0: ffffffff8d9a8b00 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775
5 locks held by kworker/u8:4/64:
4 locks held by kworker/u8:12/3546:
 #0: ffff8881404f4938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline]
 #0: ffff8881404f4938 ((wq_completion)writeback){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319
 #1: ffffc9000d7a7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline]
 #1: ffffc9000d7a7bc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319
 #2: ffff8880638980d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_trylock_shared+0x20/0xf0 fs/super.c:563
 #3: ffff88806a45da38 (&jfs_ip->commit_mutex){+.+.}-{4:4}, at: jfs_commit_inode+0x1ca/0x530 fs/jfs/inode.c:102
3 locks held by kworker/u8:14/4191:
2 locks held by getty/5596:
 #0: ffff88823bf5a8a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243
 #1: ffffc90003e762e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x444/0x1410 drivers/tty/n_tty.c:2222
8 locks held by kworker/1:3/5889:
4 locks held by syz.3.87/6505:
1 lock held by syz.3.87/6509:
 #0: ffff88806a45de08 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: inode_lock_shared include/linux/fs.h:884 [inline]
 #0: ffff88806a45de08 (&type->i_mutex_dir_key#16){++++}-{4:4}, at: lookup_slow+0x46/0x70 fs/namei.c:1824
2 locks held by syz.3.87/6513:
 #0: ffff888063898488 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff88806a45de08 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
 #1: ffff88806a45de08 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4139
2 locks held by syz.3.87/6514:
 #0: ffff888063898488 (sb_writers#19){.+.+}-{0:0}, at: mnt_want_write+0x41/0x90 fs/namespace.c:557
 #1: ffff88806a45de08 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: inode_lock_nested include/linux/fs.h:914 [inline]
 #1: ffff88806a45de08 (&type->i_mutex_dir_key#16/1){+.+.}-{4:4}, at: filename_create+0x1f8/0x3c0 fs/namei.c:4139
2 locks held by syz.4.104/6622:
 #0: ffff8880638980d0 (&type->s_umount_key#72){++++}-{4:4}, at: __super_lock fs/super.c:59 [inline]
 #0: ffff8880638980d0 (&type->s_umount_key#72){++++}-{4:4}, at: super_lock+0x2a9/0x3b0 fs/super.c:121
 #1: ffff8881433ae870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:387 [inline]
 #1: ffff8881433ae870 (&bdi->wb_switch_rwsem){+.+.}-{4:4}, at: sync_inodes_sb+0x19b/0xa50 fs/fs-writeback.c:2831
3 locks held by syz-executor/6656:
9 locks held by syz-executor/6739:
3 locks held by udevd/7105:
2 locks held by syz.5.303/8444:
 #0: ffff8880392ce1a0 (&tty->legacy_mutex){+.+.}-{4:4}, at: tty_init_dev+0x74/0x4d0 drivers/tty/tty_io.c:1406
 #1: ffff8881427c11a0 (&port->mutex){+.+.}-{4:4}, at: tty_port_open+0x121/0x2b0 drivers/tty/tty_port.c:758
3 locks held by syz.1.307/8469:
3 locks held by syz.6.308/8476:
6 locks held by udevadm/8494:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
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:307 [inline]
 watchdog+0xf93/0xfe0 kernel/hung_task.c:470
 kthread+0x70e/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: 101 PID: 5502 Comm: dhcpcd Tainted: G        W           6.16.0-syzkaller-11241-g186f3edfdd41 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:validate_chain+0x24/0x2140 kernel/locking/lockdep.c:3875
Code: 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 48 81 ec e0 00 00 00 49 89 cf 65 48 8b 05 74 eb 58 10 48 89 84 24 d8 00 00 00 <8b> 46 20 89 c1 81 e1 00 80 04 00 81 f9 00 00 04 00 0f 85 61 02 00
RSP: 0018:ffffc900047df978 EFLAGS: 00000086
RAX: 92a4b08a07da6b00 RBX: 0000000000000000 RCX: 4c17aa7073b9eb82
RDX: 0000000000000001 RSI: ffff88802f24a8e0 RDI: ffff88802f249dc0
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff81878b39
R10: ffffc900047dfd40 R11: fffff520008fbfaa R12: 000000000000010d
R13: ffff88802f24a8e0 R14: ffff88802f24a8e0 R15: 4c17aa7073b9eb82
FS:  00007f5392ead740(0000) GS:ffff8881269ce000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055556bc235c8 CR3: 0000000039f16000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
 rt_spin_lock+0x88/0x2c0 kernel/locking/spinlock_rt.c:56
 spin_lock_irq include/linux/spinlock_rt.h:93 [inline]
 __set_current_blocked+0xe9/0x2c0 kernel/signal.c:3222
 restore_saved_sigmask include/linux/sched/signal.h:539 [inline]
 restore_saved_sigmask_unless include/linux/sched/signal.h:549 [inline]
 poll_select_finish+0x1e7/0x5f0 fs/select.c:301
 __do_sys_ppoll fs/select.c:1116 [inline]
 __se_sys_ppoll+0x213/0x260 fs/select.c:1095
 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: 0033:0x7f5392f37407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007fff9ddae340 EFLAGS: 00000202 ORIG_RAX: 000000000000010f
RAX: ffffffffffffffda RBX: 00007f5392ead740 RCX: 00007f5392f37407
RDX: 00007fff9ddae380 RSI: 0000000000000005 RDI: 0000564f9c731c30
RBP: 00007fff9ddae680 R08: 0000000000000008 R09: 0000000000000000
R10: 00007fff9ddae680 R11: 0000000000000202 R12: 0000564f8a8c95e0
R13: 0000564f9c749df0 R14: 0000000000000000 R15: 00007fff9ddae430
 </TASK>