INFO: task syz.1.72:4196 blocked for more than 430 seconds.
      Not tainted 6.12.0-rc1-syzkaller-00012-g5f153a692bac #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz.1.72        state:D stack:0     pid:4196  tgid:4195  ppid:3156   flags:0x00000002
Call Trace:
[<ffffffff85fe3a74>] context_switch kernel/sched/core.c:5315 [inline]
[<ffffffff85fe3a74>] __schedule+0xd5a/0x3886 kernel/sched/core.c:6675
[<ffffffff85fe6664>] __schedule_loop kernel/sched/core.c:6752 [inline]
[<ffffffff85fe6664>] schedule+0xc4/0x324 kernel/sched/core.c:6767
[<ffffffff85ff9412>] schedule_timeout+0x1e2/0x296 kernel/time/timer.c:2591
[<ffffffff85fe8042>] do_wait_for_common kernel/sched/completion.c:95 [inline]
[<ffffffff85fe8042>] __wait_for_common+0x1ca/0x4b6 kernel/sched/completion.c:116
[<ffffffff85fe8348>] wait_for_common kernel/sched/completion.c:127 [inline]
[<ffffffff85fe8348>] wait_for_completion+0x1a/0x22 kernel/sched/completion.c:148
[<ffffffff802d83b6>] rcu_barrier+0x2dc/0x6cc kernel/rcu/tree.c:4629
[<ffffffff84d323f6>] netdev_run_todo+0x294/0x105e net/core/dev.c:10778
[<ffffffff84d5e85e>] rtnl_unlock+0x14/0x1c net/core/rtnetlink.c:152
[<ffffffff82f49534>] tun_detach drivers/net/tun.c:704 [inline]
[<ffffffff82f49534>] tun_chr_close+0xde/0x230 drivers/net/tun.c:3517
[<ffffffff80a2c758>] __fput+0x378/0x9e6 fs/file_table.c:431
[<ffffffff80a2ce6c>] ____fput+0x1c/0x26 fs/file_table.c:459
[<ffffffff8014fb7c>] task_work_run+0x16a/0x25e kernel/task_work.c:228
[<ffffffff800d8f4c>] exit_task_work include/linux/task_work.h:40 [inline]
[<ffffffff800d8f4c>] do_exit+0xa4c/0x2986 kernel/exit.c:939
[<ffffffff800db3e6>] do_group_exit+0xd4/0x26c kernel/exit.c:1088
[<ffffffff8010db36>] get_signal+0x1e98/0x23b0 kernel/signal.c:2917
[<ffffffff8000bb06>] arch_do_signal_or_restart+0x8d6/0x1190 arch/riscv/kernel/signal.c:437
[<ffffffff85fdac04>] exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
[<ffffffff85fdac04>] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
[<ffffffff85fdac04>] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
[<ffffffff85fdac04>] syscall_exit_to_user_mode+0x2a6/0x31e kernel/entry/common.c:218
[<ffffffff85fd9b26>] do_trap_ecall_u+0x86/0x216 arch/riscv/kernel/traps.c:345
[<ffffffff85ffcac6>] _new_vmalloc_restore_context_a0+0xc2/0xce

Showing all locks held in the system:
2 locks held by kworker/1:1/32:
1 lock held by khungtaskd/36:
 #0: ffffffff87fcc100 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x68/0x2d6 kernel/locking/lockdep.c:6716
2 locks held by kworker/1:2/1447:
2 locks held by syslogd/2966:
 #0: ff6000006ec2dd18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested kernel/sched/core.c:593 [inline]
 #0: ff6000006ec2dd18 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock kernel/sched/sched.h:1505 [inline]
 #0: ff6000006ec2dd18 (&rq->__lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1804 [inline]
 #0: ff6000006ec2dd18 (&rq->__lock){-.-.}-{2:2}, at: __schedule+0x280/0x3886 kernel/sched/core.c:6575
 #1: ff6000001bb4b298 (rlock-AF_UNIX){....}-{2:2}, at: __skb_try_recv_datagram+0x148/0x48a net/core/datagram.c:263
2 locks held by getty/3119:
 #0: ff60000017be90a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3a/0x46 drivers/tty/tty_ldsem.c:340
 #1: ff2000000008b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xd7c/0x129a drivers/tty/n_tty.c:2211
1 lock held by sshd/3149:
2 locks held by syz-executor/3151:
2 locks held by kworker/1:0/3668:
2 locks held by kworker/1:3/3841:
2 locks held by kworker/1:4/3844:
1 lock held by syz.1.72/4196:
 #0: ffffffff87fdc6c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x56/0x6cc kernel/rcu/tree.c:4561
2 locks held by kworker/1:6/4422:
5 locks held by kworker/0:6/4424:
2 locks held by kworker/1:7/4450:
2 locks held by kworker/1:8/4507:
1 lock held by syz.0.95/4619:
2 locks held by kworker/1:10/4652:
1 lock held by syz-executor/4660:
 #0: ffffffff87fdc6c0 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x56/0x6cc kernel/rcu/tree.c:4561
3 locks held by kworker/1:11/4665:
2 locks held by kworker/u9:0/4670:
 #0: ff60000011071148 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work+0x848/0x1dae kernel/workqueue.c:3204
 #1: ff20000003da7c90 ((work_completion)(&sub_info->work)){+.+.}-{0:0}, at: process_one_work+0x870/0x1dae kernel/workqueue.c:3204
2 locks held by kworker/1:12/4741:
2 locks held by kworker/1:13/5026:
2 locks held by kworker/1:14/5090:
2 locks held by kworker/1:15/5229:
6 locks held by syz-executor/5270:
 #0: ff6000001dbb8420 (sb_writers#8){.+.+}-{0:0}, at: __sb_start_write include/linux/fs.h:1716 [inline]
 #0: ff6000001dbb8420 (sb_writers#8){.+.+}-{0:0}, at: sb_start_write include/linux/fs.h:1852 [inline]
 #0: ff6000001dbb8420 (sb_writers#8){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #0: ff6000001dbb8420 (sb_writers#8){.+.+}-{0:0}, at: vfs_write+0x728/0x9b4 fs/read_write.c:679
 #1: ff6000003b732888 (&of->mutex#2){+.+.}-{3:3}, at: kernfs_fop_write_iter+0x23a/0x460 fs/kernfs/file.c:325
 #2: ffffffff88021488 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_lock include/linux/cgroup.h:368 [inline]
 #2: ffffffff88021488 (cgroup_mutex){+.+.}-{3:3}, at: cgroup_kn_lock_live+0x11c/0x50c kernel/cgroup/cgroup.c:1662
 #3: ffffffff87e72150 (cpu_hotplug_lock){++++}-{0:0}, at: cpus_read_lock+0x14/0x1c kernel/cpu.c:490
 #4: ffffffff88021db0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2437 [inline]
 #4: ffffffff88021db0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_attach_lock kernel/cgroup/cgroup.c:2433 [inline]
 #4: ffffffff88021db0 (cgroup_threadgroup_rwsem){++++}-{0:0}, at: cgroup_procs_write_start+0x1aa/0x5d4 kernel/cgroup/cgroup.c:2939
 #5: ffffffff87fdc7f8 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock+0x266/0x384 kernel/rcu/tree_exp.h:297
2 locks held by kworker/1:17/5734:
2 locks held by syz.4.105/5748:

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

NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 36 Comm: khungtaskd Not tainted 6.12.0-rc1-syzkaller-00012-g5f153a692bac #0
Hardware name: riscv-virtio,qemu (DT)
Call Trace:
[<ffffffff80010a14>] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:130
[<ffffffff85f7c3cc>] show_stack+0x34/0x40 arch/riscv/kernel/stacktrace.c:136
[<ffffffff85fd797a>] __dump_stack lib/dump_stack.c:94 [inline]
[<ffffffff85fd797a>] dump_stack_lvl+0x122/0x196 lib/dump_stack.c:120
[<ffffffff85fd7a0a>] dump_stack+0x1c/0x24 lib/dump_stack.c:129
[<ffffffff85f3faae>] nmi_cpu_backtrace+0x39c/0x39e lib/nmi_backtrace.c:113
[<ffffffff85f3fd66>] nmi_trigger_cpumask_backtrace+0x2b6/0x456 lib/nmi_backtrace.c:62
[<ffffffff80019974>] arch_trigger_cpumask_backtrace+0x2c/0x3c arch/riscv/kernel/smp.c:347
[<ffffffff80432c3c>] trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline]
[<ffffffff80432c3c>] check_hung_uninterruptible_tasks kernel/hung_task.c:223 [inline]
[<ffffffff80432c3c>] watchdog+0xcfa/0x1178 kernel/hung_task.c:379
[<ffffffff80154e14>] kthread+0x28c/0x3a6 kernel/kthread.c:389
[<ffffffff85ffcbde>] ret_from_fork+0xe/0x18 arch/riscv/kernel/entry.S:326
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 4450 Comm: kworker/1:7 Not tainted 6.12.0-rc1-syzkaller-00012-g5f153a692bac #0
Hardware name: riscv-virtio,qemu (DT)
Workqueue: events_power_efficient neigh_periodic_work
epc : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
epc : _raw_spin_unlock_irqrestore+0x36/0xd6 kernel/locking/spinlock.c:194
 ra : __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
 ra : _raw_spin_unlock_irqrestore+0x86/0xd6 kernel/locking/spinlock.c:194
epc : ffffffff85ffb7aa ra : ffffffff85ffb7fa sp : ff20000000016e60
 gp : ffffffff897bea80 tp : ff60000011b13480 t0 : ff60000011b13fa0
 t1 : fffffffef215129b t2 : 0000000000000001 s0 : ff20000000016e80
 s1 : 0000000000000002 a0 : 0000000000000001 a1 : ffffffff8643e620
 a2 : 0000000000000003 a3 : 0000000000000102 a4 : 0000000000000001
 a5 : 0000000000000000 a6 : ff60000011b13fe8 a7 : 1fec0000023627fd
 s2 : ffffffff90a894d8 s3 : dead000000000100 s4 : dead000000000122
 s5 : dfffffff00000000 s6 : ff6000003c03dc00 s7 : ff6000003c03d800
 s8 : 0000000000000001 s9 : 0000000000000001 s10: ff6000003c03dc00
 s11: ff6000003c03d000 t3 : 1fec0000023627f3 t4 : fffffffef215129b
 t5 : fffffffef215129c t6 : 1fec00000236280c
status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000001
[<ffffffff85ffb7aa>] arch_local_irq_restore arch/riscv/include/asm/irqflags.h:51 [inline]
[<ffffffff85ffb7aa>] __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:151 [inline]
[<ffffffff85ffb7aa>] _raw_spin_unlock_irqrestore+0x36/0xd6 kernel/locking/spinlock.c:194
[<ffffffff814ad66a>] __debug_check_no_obj_freed lib/debugobjects.c:998 [inline]
[<ffffffff814ad66a>] debug_check_no_obj_freed+0x26a/0x4fc lib/debugobjects.c:1019
[<ffffffff808d709c>] slab_free_hook mm/slub.c:2274 [inline]
[<ffffffff808d709c>] slab_free mm/slub.c:4580 [inline]
[<ffffffff808d709c>] kfree+0x316/0x4ce mm/slub.c:4728
[<ffffffff84c971b4>] skb_kfree_head net/core/skbuff.c:1086 [inline]
[<ffffffff84c971b4>] skb_free_head+0x230/0x2ec net/core/skbuff.c:1098
[<ffffffff84ca2952>] skb_release_data+0x6ec/0x86a net/core/skbuff.c:1125
[<ffffffff84cb041e>] skb_release_all net/core/skbuff.c:1190 [inline]
[<ffffffff84cb041e>] __kfree_skb net/core/skbuff.c:1204 [inline]
[<ffffffff84cb041e>] consume_skb net/core/skbuff.c:1436 [inline]
[<ffffffff84cb041e>] consume_skb+0xca/0xfa net/core/skbuff.c:1430
[<ffffffff852a7176>] nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
[<ffffffff852a7176>] nft_synproxy_do_eval+0x8b6/0xa52 net/netfilter/nft_synproxy.c:141
[<ffffffff852a7370>] nft_synproxy_eval+0x28/0x36 net/netfilter/nft_synproxy.c:247
[<ffffffff851dd7c2>] expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline]
[<ffffffff851dd7c2>] nft_do_chain+0x328/0x1598 net/netfilter/nf_tables_core.c:288
[<ffffffff8523729c>] nft_do_chain_inet+0x180/0x316 net/netfilter/nft_chain_filter.c:161
[<ffffffff85112730>] nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
[<ffffffff85112730>] nf_hook_slow+0xb8/0x1ec net/netfilter/core.c:626
[<ffffffff8533038a>] nf_hook include/linux/netfilter.h:269 [inline]
[<ffffffff8533038a>] NF_HOOK include/linux/netfilter.h:312 [inline]
[<ffffffff8533038a>] ip_local_deliver+0x2ea/0x568 net/ipv4/ip_input.c:254
[<ffffffff8532ee32>] dst_input include/net/dst.h:460 [inline]
[<ffffffff8532ee32>] ip_rcv_finish+0x1b0/0x2d2 net/ipv4/ip_input.c:449
[<ffffffff853306de>] NF_HOOK include/linux/netfilter.h:314 [inline]
[<ffffffff853306de>] NF_HOOK include/linux/netfilter.h:308 [inline]
[<ffffffff853306de>] ip_rcv+0xd6/0x44e net/ipv4/ip_input.c:569
[<ffffffff84d21a54>] __netif_receive_skb_one_core+0x106/0x16e net/core/dev.c:5662
[<ffffffff84d21cd4>] __netif_receive_skb+0x2c/0x144 net/core/dev.c:5775
[<ffffffff84d22d58>] process_backlog+0x4fc/0x1cbc net/core/dev.c:6107
[<ffffffff84d2760a>] __napi_poll.constprop.0+0xaa/0x4b8 net/core/dev.c:6771
[<ffffffff84d2842a>] napi_poll net/core/dev.c:6840 [inline]
[<ffffffff84d2842a>] net_rx_action+0xa12/0xf10 net/core/dev.c:6962
[<ffffffff800e0fba>] handle_softirqs+0x4a6/0x10de kernel/softirq.c:554
[<ffffffff85ffccb8>] __do_softirq+0x12/0x1a kernel/softirq.c:588
[<ffffffff80006f74>] ___do_softirq+0x18/0x20 arch/riscv/kernel/irq.c:85
[<ffffffff85ffcc1a>] call_on_irq_stack+0x32/0x40 arch/riscv/kernel/entry.S:355