INFO: task syz.0.17:6077 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.17 state:D stack:27272 pid:6077 tgid:6073 ppid:5991 task_flags:0x400740 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5352 [inline] __schedule+0x1665/0x5590 kernel/sched/core.c:6964 __schedule_loop kernel/sched/core.c:7047 [inline] schedule+0x164/0x360 kernel/sched/core.c:7062 schedule_timeout+0xc3/0x2c0 kernel/time/sleep_timeout.c:75 do_wait_for_common kernel/sched/completion.c:100 [inline] __wait_for_common+0x3c0/0x690 kernel/sched/completion.c:121 wait_for_common kernel/sched/completion.c:132 [inline] wait_for_completion_state+0x1c/0x40 kernel/sched/completion.c:269 coredump_wait fs/coredump.c:534 [inline] vfs_coredump+0x9c7/0x4280 fs/coredump.c:1197 get_signal+0x1107/0x1330 kernel/signal.c:3020 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline] exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:269 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline] do_syscall_64+0x32d/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f65eb39c799 RSP: 002b:00007f65ea9fe0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 00000000000000ca RBX: 00007f65eb616098 RCX: 00007f65eb39c799 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f65eb61609c RBP: 00007f65eb616090 R08: 3fffffffffffffff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f65eb616128 R14: 00007fff290e5c80 R15: 00007fff290e5d68 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 4 locks held by kworker/u8:5/114: #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x31/0x150 kernel/sched/core.c:647 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:1004 [inline] #2: ffff8880b8626118 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1ae/0xf30 kernel/time/timer.c:1085 #3: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: spin_lock_bh include/linux/spinlock.h:348 [inline] #3: ffffffff8e75f420 (rcu_read_lock){....}-{1:3}, at: cfg80211_inform_single_bss_data+0xbb8/0x1b70 net/wireless/scan.c:2367 2 locks held by getty/5592: #0: ffff888037cb80a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 31 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0x1002/0x1060 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/27/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x2e/0x70 kernel/kcov.c:217 Code: 48 8b 04 24 65 48 8b 0d 48 8c 57 11 65 8b 15 69 8c 57 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 a4 16 00 00 00 <74> 2c 8b 91 80 16 00 00 83 fa 02 75 21 48 8b 91 88 16 00 00 48 8b RSP: 0018:ffffc90000006f38 EFLAGS: 00000246 RAX: ffffffff8985c449 RBX: ffffffff9ae2b800 RCX: ffffffff8e494ec0 RDX: 0000000000000100 RSI: ffffffff8188dc0a RDI: ffffffff8188dc0a RBP: ffffc900000070c8 R08: ffffc90000006ebf R09: 0000000000000000 R10: ffffc90000006ea0 R11: fffff52000000dd8 R12: e00000000ca3a8ff R13: e00000000ca3a8fe R14: 1ffffffff35c5700 R15: e00000000ca3a8fe FS: 0000000000000000(0000) GS:ffff88812543d000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000562b21b561b8 CR3: 000000000e54c000 CR4: 00000000003526f0 Call Trace: save_dst_trace_buffer+0x1a9/0x540 net/core/dst.c:106 ip6_route_output_flags+0x3df/0x5e0 net/ipv6/route.c:-1 ip6_route_output include/net/ip6_route.h:93 [inline] ip6_dst_lookup_tail+0x1c3/0x15a0 net/ipv6/ip6_output.c:1128 ip6_dst_lookup_flow+0x47/0xe0 net/ipv6/ip6_output.c:1259 udp_tunnel6_dst_lookup+0x24d/0x470 net/ipv6/ip6_udp_tunnel.c:165 geneve6_xmit_skb drivers/net/geneve.c:1428 [inline] geneve_xmit+0x13a0/0x3160 drivers/net/geneve.c:1515 __netdev_start_xmit include/linux/netdevice.h:5339 [inline] netdev_start_xmit include/linux/netdevice.h:5348 [inline] xmit_one net/core/dev.c:3873 [inline] dev_hard_start_xmit+0x2d8/0x870 net/core/dev.c:3889 __dev_queue_xmit+0x17a7/0x38d0 net/core/dev.c:4839 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip6_output+0x340/0x550 net/ipv6/ip6_output.c:246 dst_output include/net/dst.h:488 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] ndisc_send_skb+0xd0b/0x1670 net/ipv6/ndisc.c:512 addrconf_rs_timer+0x395/0x6d0 net/ipv6/addrconf.c:4041 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748 expire_timers kernel/time/timer.c:1799 [inline] __run_timers kernel/time/timer.c:2373 [inline] __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385 run_timer_base kernel/time/timer.c:2394 [inline] run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404 handle_softirqs+0x22a/0x870 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x220 kernel/softirq.c:739 irq_exit_rcu+0x9/0x30 kernel/softirq.c:756 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63 Code: 7d 69 02 e9 93 ec 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d b3 e3 15 00 fb f4 cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e407dc0 EFLAGS: 00000246 RAX: 000000000018bb4d RBX: ffffffff819b829a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8df14eff RDI: ffffffff8c285fe0 RBP: ffffffff8e407eb0 R08: ffff8880b863399b R09: 1ffff110170c6733 R10: dffffc0000000000 R11: ffffed10170c6734 R12: ffffffff901250f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1c929d8 arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ba/0x5d0 kernel/sched/idle.c:341 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:439 rest_init+0x2de/0x300 init/main.c:761 start_kernel+0x38a/0x3e0 init/main.c:1212 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147