INFO: task syz.2.506:5716 blocked for more than 430 seconds. Not tainted 6.16.0-rc7-syzkaller-g7b388bf7a9d9 #0 Blocked by coredump. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.506 state:D stack:0 pid:5716 tgid:5716 ppid:4333 task_flags:0x40044c flags:0x0000000c Call Trace: [] context_switch kernel/sched/core.c:5397 [inline] [] __schedule+0x105c/0x4088 kernel/sched/core.c:6786 [] __schedule_loop kernel/sched/core.c:6864 [inline] [] schedule+0xc4/0x35e kernel/sched/core.c:6879 [] schedule_timeout+0x1c6/0x2b2 kernel/time/sleep_timeout.c:75 [] do_wait_for_common+0x1c2/0x3d0 kernel/sched/completion.c:95 [] __wait_for_common kernel/sched/completion.c:116 [inline] [] wait_for_common kernel/sched/completion.c:127 [inline] [] wait_for_completion+0x40/0x5c kernel/sched/completion.c:148 [] rcu_barrier+0x2e4/0x66c kernel/rcu/tree.c:3854 [] netdev_run_todo+0x2bc/0x10de net/core/dev.c:11376 [] rtnl_unlock+0x14/0x1c net/core/rtnetlink.c:157 [] tun_detach drivers/net/tun.c:639 [inline] [] tun_chr_close+0xde/0x230 drivers/net/tun.c:3396 [] __fput+0x382/0xa8c fs/file_table.c:465 [] ____fput+0x1c/0x26 fs/file_table.c:493 [] task_work_run+0x16a/0x25e kernel/task_work.c:227 [] exit_task_work include/linux/task_work.h:40 [inline] [] do_exit+0x866/0x28b6 kernel/exit.c:964 [] do_group_exit+0xd4/0x26c kernel/exit.c:1105 [] get_signal+0x208c/0x230c kernel/signal.c:3034 [] arch_do_signal_or_restart+0x6ba/0x1cd4 arch/riscv/kernel/signal.c:534 [] exit_to_user_mode_loop+0x90/0x134 kernel/entry/common.c:111 [] exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] [] syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline] [] syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline] [] do_trap_ecall_u+0x3f0/0x530 arch/riscv/kernel/traps.c:357 [] handle_exception+0x15e/0x16a arch/riscv/kernel/entry.S:231 Showing all locks held in the system: 1 lock held by khungtaskd/38: #0: ffffffff885dbd80 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2a/0x1a0 kernel/locking/lockdep.c:6766 2 locks held by getty/3169: #0: ffffaf80190b60a0 (&tty->ldisc_sem){++++}-{0:0}, at: ldsem_down_read+0x3a/0x46 drivers/tty/tty_ldsem.c:340 #1: ffff8f800008e2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x3e4/0x12ba drivers/tty/n_tty.c:2222 1 lock held by syz-executor/3207: 2 locks held by kworker/1:1/3214: 4 locks held by kworker/1:5/3934: 3 locks held by kworker/0:0/4314: 2 locks held by kworker/1:0/4847: 2 locks held by kworker/1:6/5242: 2 locks held by kworker/1:2/5655: 1 lock held by syz.2.506/5716: #0: ffffffff885ebe80 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x56/0x66c kernel/rcu/tree.c:3786 2 locks held by kworker/1:4/5718: 2 locks held by kworker/1:7/5735: 2 locks held by kworker/1:8/5738: 2 locks held by syz-executor/5742: 2 locks held by kworker/1:9/5754: 2 locks held by kworker/1:10/5758: 2 locks held by kworker/1:11/5762: 2 locks held by kworker/1:13/5836: 2 locks held by kworker/1:14/5884: 3 locks held by kworker/1:15/5912: 2 locks held by kworker/1:16/5956: 2 locks held by kworker/1:18/6090: 3 locks held by kworker/u9:1/6134: 2 locks held by syz.0.537/6149: 2 locks held by syz.0.537/6153: 4 locks held by cmp/6154: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 38 Comm: khungtaskd Not tainted 6.16.0-rc7-syzkaller-g7b388bf7a9d9 #0 PREEMPT Hardware name: riscv-virtio,qemu (DT) Call Trace: [] dump_backtrace+0x2e/0x3c arch/riscv/kernel/stacktrace.c:132 [] show_stack+0x30/0x3c arch/riscv/kernel/stacktrace.c:138 [] __dump_stack lib/dump_stack.c:94 [inline] [] dump_stack_lvl+0x12e/0x1a6 lib/dump_stack.c:120 [] dump_stack+0x1c/0x24 lib/dump_stack.c:129 [] nmi_cpu_backtrace+0x3b0/0x3b2 lib/nmi_backtrace.c:113 [] nmi_trigger_cpumask_backtrace+0x2c4/0x466 lib/nmi_backtrace.c:62 [] arch_trigger_cpumask_backtrace+0x2c/0x42 arch/riscv/kernel/smp.c:350 [] trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:307 [inline] [] watchdog+0xd0e/0x11fe kernel/hung_task.c:470 [] kthread+0x3a4/0x7e0 kernel/kthread.c:464 [] ret_from_fork_kernel+0x2a/0xbec arch/riscv/kernel/process.c:228 [] ret_from_fork_kernel_asm+0x16/0x18 arch/riscv/kernel/entry.S:362 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 3934 Comm: kworker/1:5 Not tainted 6.16.0-rc7-syzkaller-g7b388bf7a9d9 #0 PREEMPT Hardware name: riscv-virtio,qemu (DT) Workqueue: wg-crypt-wg2 wg_packet_encrypt_worker epc : skb_dst include/linux/skbuff.h:1156 [inline] epc : l3mdev_l3_out include/net/l3mdev.h:210 [inline] epc : l3mdev_ip_out include/net/l3mdev.h:229 [inline] epc : __ip_local_out+0x256/0xbe4 net/ipv4/ip_output.c:112 ra : __ip_local_out+0x23c/0xbe4 net/ipv4/ip_output.c:107 epc : ffffffff8583981c ra : ffffffff85839802 sp : ffff8f8000016e70 gp : ffffffff89e816e0 tp : ffffaf801baacec0 t0 : ffff8f8000016ec8 t1 : fffffffff2f20000 t2 : fffffffff2f20000 s0 : ffff8f8000016fa0 s1 : ffffaf8018c31280 a0 : 0000000000000000 a1 : ffffaf801baacec0 a2 : 00000000000f0000 a3 : 0000000000f00000 a4 : 0000000000000000 a5 : 0000000000000000 a6 : fffffffff3f30000 a7 : fffffffff1f1f1f1 s2 : ffffaf801f0b9e00 s3 : 1ffff1f000002dd4 s4 : ffff8f8000016f40 s5 : 1ffff5f00318625b s6 : 0000000000000000 s7 : ffffaf8018c312d8 s8 : 0000000000010000 s9 : 0000000000002800 s10: 0000000000000000 s11: 1ffff1f000002e3c t3 : ffffaf8036346408 t4 : 0000000000001fff t5 : 00000000000000c8 t6 : ffff8f8000016d14 ssp : 0000000000000000 status: 0000000200000120 badaddr: 0000000000000000 cause: 8000000000000001 [] skb_dst include/linux/skbuff.h:1156 [inline] [] l3mdev_l3_out include/net/l3mdev.h:210 [inline] [] l3mdev_ip_out include/net/l3mdev.h:229 [inline] [] __ip_local_out+0x256/0xbe4 net/ipv4/ip_output.c:112 [] ip_local_out+0x2e/0x1a8 net/ipv4/ip_output.c:127 [] synproxy_send_tcp.isra.0+0x3de/0x5d2 net/netfilter/nf_synproxy_core.c:439 [] synproxy_send_client_synack+0x6cc/0x94e net/netfilter/nf_synproxy_core.c:484 [] nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:59 [inline] [] nft_synproxy_do_eval+0x858/0xab8 net/netfilter/nft_synproxy.c:141 [] nft_synproxy_eval+0x28/0x4e net/netfilter/nft_synproxy.c:247 [] expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] [] nft_do_chain+0x328/0x1598 net/netfilter/nf_tables_core.c:285 [] nft_do_chain_inet+0x180/0x34c net/netfilter/nft_chain_filter.c:161 [] nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] [] nf_hook_slow+0xb8/0x1ec net/netfilter/core.c:623 [] nf_hook include/linux/netfilter.h:272 [inline] [] NF_HOOK include/linux/netfilter.h:315 [inline] [] ip_local_deliver+0x2ea/0x568 net/ipv4/ip_input.c:254 [] dst_input include/net/dst.h:469 [inline] [] ip_rcv_finish+0x1b0/0x2d2 net/ipv4/ip_input.c:448 [] NF_HOOK include/linux/netfilter.h:317 [inline] [] NF_HOOK include/linux/netfilter.h:311 [inline] [] ip_rcv+0xd6/0x44e net/ipv4/ip_input.c:568 [] __netif_receive_skb_one_core+0x106/0x16e net/core/dev.c:5977 [] __netif_receive_skb+0x2e/0x146 net/core/dev.c:6090 [] process_backlog+0x4fe/0x1dc8 net/core/dev.c:6442 [] __napi_poll.constprop.0+0xaa/0x4c2 net/core/dev.c:7414 [] napi_poll net/core/dev.c:7478 [inline] [] net_rx_action+0xb42/0xffa net/core/dev.c:7605 [] handle_softirqs+0x500/0x1436 kernel/softirq.c:579 [] __do_softirq+0x12/0x1a kernel/softirq.c:613 [] ___do_softirq+0x18/0x20 arch/riscv/kernel/irq.c:85 [] call_on_irq_stack+0x32/0x40 arch/riscv/kernel/entry.S:395