INFO: task syz-executor:13455 blocked for more than 143 seconds. Not tainted 6.1.119-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:20472 pid:13455 ppid:1 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 wb_wait_for_completion+0x162/0x290 fs/fs-writeback.c:191 sync_inodes_sb+0x28f/0xb10 fs/fs-writeback.c:2739 sync_filesystem+0x16b/0x220 fs/sync.c:64 generic_shutdown_super+0x6b/0x340 fs/super.c:474 kill_block_super+0x7a/0xe0 fs/super.c:1470 deactivate_locked_super+0xa0/0x110 fs/super.c:332 cleanup_mnt+0x490/0x520 fs/namespace.c:1186 task_work_run+0x246/0x300 kernel/task_work.c:203 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop+0xde/0x100 kernel/entry/common.c:177 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbfb7f7fb47 RSP: 002b:00007ffdf9b27ff8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6 RAX: 0000000000000000 RBX: 00007fbfb7ff15fc RCX: 00007fbfb7f7fb47 RDX: 0000000000000000 RSI: 0000000000000009 RDI: 00007ffdf9b280b0 RBP: 00007ffdf9b280b0 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007ffdf9b29130 R13: 00007fbfb7ff15fc R14: 00000000001714d6 R15: 00007ffdf9b29170 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8d32b110 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8d32b910 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x29/0xe30 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32af40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6510 2 locks held by getty/4011: #0: ffff88814d634098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc900032462f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a7/0x1db0 drivers/tty/n_tty.c:2198 4 locks held by kworker/u4:23/9174: 2 locks held by syz-executor/13455: #0: ffff888076c8a0e0 (&type->s_umount_key#48 ){++++}-{3:3}, at: deactivate_super+0xa9/0xe0 fs/super.c:362 #1: ffff888024c5c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:362 [inline] #1: ffff888024c5c7d0 (&bdi->wb_switch_rwsem){+.+.}-{3:3}, at: sync_inodes_sb+0x270/0xb10 fs/fs-writeback.c:2737 3 locks held by syz.1.2771/17558: 1 lock held by syz.1.2808/17664: ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 27 Comm: khungtaskd Not tainted 6.1.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 nmi_cpu_backtrace+0x4e1/0x560 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1ae/0x3f0 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:220 [inline] watchdog+0xf88/0xfd0 kernel/hung_task.c:377 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 0 to CPUs 1: IPVS: fo: UDP 224.0.0.2:0 - no destination available NMI backtrace for cpu 1 CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.1.119-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:serial_lsr_in drivers/tty/serial/8250/8250.h:140 [inline] RIP: 0010:wait_for_lsr drivers/tty/serial/8250/8250_port.c:2100 [inline] RIP: 0010:serial8250_console_fifo_write drivers/tty/serial/8250/8250_port.c:3367 [inline] RIP: 0010:serial8250_console_write+0x1063/0x1750 drivers/tty/serial/8250/8250_port.c:3445 Code: 38 00 74 0d 48 8b bc 24 88 00 00 00 e8 d6 ae 2e fd 48 8b 7c 24 20 be 05 00 00 00 ff 57 50 09 c3 48 8b 44 24 58 42 0f b6 04 38 <84> c0 4d 89 fc 75 5e 48 8b 44 24 38 44 0f b7 38 66 41 21 df 48 8b RSP: 0018:ffffc900001b65a0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 00000000000003fd RSI: 0000000000000000 RDI: 0000000000000020 RBP: ffffc900001b6770 R08: ffffffff84b39472 R09: ffffed10048fc047 R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff9737ae30 R13: 0000000000002702 R14: 0000000000000000 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000203c9030 CR3: 000000001fb58000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: call_console_driver kernel/printk/printk.c:1977 [inline] console_emit_next_record+0xbb4/0x1000 kernel/printk/printk.c:2777 console_unlock+0x278/0x7c0 kernel/printk/printk.c:2906 vprintk_emit+0x523/0x740 kernel/printk/printk.c:2303 _printk+0xd1/0x111 kernel/printk/printk.c:2328 ip_vs_fo_schedule+0x1c3/0x1e0 net/netfilter/ipvs/ip_vs_fo.c:49 ip_vs_sched_persist net/netfilter/ipvs/ip_vs_core.c:353 [inline] ip_vs_schedule+0xe69/0x2270 net/netfilter/ipvs/ip_vs_core.c:508 udp_conn_schedule+0x38d/0x740 net/netfilter/ipvs/ip_vs_proto_udp.c:78 ip_vs_try_to_schedule net/netfilter/ipvs/ip_vs_core.c:1488 [inline] ip_vs_in_hook+0xe16/0x2230 net/netfilter/ipvs/ip_vs_core.c:2056 nf_hook_entry_hookfn include/linux/netfilter.h:142 [inline] nf_hook_slow+0xae/0x1e0 net/netfilter/core.c:614 nf_hook+0x2c0/0x450 include/linux/netfilter.h:257 __ip_local_out+0x38b/0x4a0 net/ipv4/ip_output.c:115 ip_local_out+0x26/0x120 net/ipv4/ip_output.c:124 iptunnel_xmit+0x513/0x920 net/ipv4/ip_tunnel_core.c:82 udp_tunnel_xmit_skb+0x230/0x350 net/ipv4/udp_tunnel_core.c:172 tipc_udp_xmit+0x5ee/0xaf0 net/tipc/udp_media.c:198 tipc_bearer_xmit_skb+0x2ed/0x450 net/tipc/bearer.c:577 tipc_disc_timeout+0x5ea/0x760 net/tipc/discover.c:338 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504 expire_timers kernel/time/timer.c:1549 [inline] __run_timers+0x67c/0x890 kernel/time/timer.c:1820 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833 handle_softirqs+0x2ee/0xa40 kernel/softirq.c:571 run_ksoftirqd+0xc6/0x120 kernel/softirq.c:938 smpboot_thread_fn+0x52c/0xa30 kernel/smpboot.c:164 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295