INFO: task syz-executor:4050 blocked for more than 122 seconds. Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor state:D stack:0 pid:4050 tgid:4050 ppid:1 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5924 [inline] __schedule+0x145b/0x1f10 kernel/sched/core.c:7750 __schedule_loop kernel/sched/core.c:7831 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7846 schedule_timeout+0xb2/0x3a0 kernel/time/timer.c:2595 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common+0x359/0x630 kernel/sched/completion.c:127 wait_for_completion+0x1c/0x40 kernel/sched/completion.c:148 rcu_barrier+0x415/0x530 kernel/rcu/tree.c:4642 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10864 rtnl_unlock+0x12/0x20 net/core/rtnetlink.c:152 tun_detach drivers/net/tun.c:704 [inline] tun_chr_close+0xc5/0x150 drivers/net/tun.c:3517 __fput+0x1fb/0xa00 fs/file_table.c:431 ____fput+0x20/0x30 fs/file_table.c:459 task_work_run+0x1e0/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9b4/0x2630 kernel/exit.c:944 do_group_exit+0x22a/0x300 kernel/exit.c:1094 get_signal+0x139d/0x14f0 kernel/signal.c:2934 arch_do_signal_or_restart+0x96/0x720 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fc09ff8d560 RSP: 002b:00007fffb33dac58 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 000000000001031c RCX: 00007fc09ff8d560 RDX: 00000000ffffffff RSI: 0000000040086602 RDI: 0000000000000005 RBP: 00007fffb33dad10 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fffb33dbda0 R13: 00007fc0a0010925 R14: 000055557bb114a8 R15: 0000000000000005 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:229 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:385 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 33 Comm: rcuop/1 Not tainted 6.12.23-syzkaller-gd9fd901baa98 #0 f1acc3ef52b3e732a05c4f7a2560722db90bb473 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x90 kernel/kcov.c:313 Code: 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 5d c3 cc cc cc cc cc 66 90 b8 c9 0f 6f b3 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 48 89 e5 48 8b 45 08 65 48 8b 14 25 40 e9 04 00 65 RSP: 0018:ffffc90000230150 EFLAGS: 00000246 RAX: ffffffff84de0bdb RBX: 0000000000000017 RCX: ffff888103678000 RDX: 0000000000000100 RSI: 0000000000000017 RDI: 0000000000000000 RBP: ffffc900002301e8 R08: ffffc90000230540 R09: ffffc90000230550 R10: ffffc900002306b0 R11: fffff520000460da R12: dffffc0000000000 R13: ffff8881087024c0 R14: 0000000000000003 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f07ba4cb010 CR3: 0000000109bf4000 CR4: 00000000003526b0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_match+0x176/0x10f0 net/ipv6/route.c:786 __find_rr_leaf+0x23c/0x790 net/ipv6/route.c:869 find_rr_leaf net/ipv6/route.c:890 [inline] rt6_select net/ipv6/route.c:934 [inline] fib6_table_lookup+0x2c5/0x9b0 net/ipv6/route.c:2229 ip6_pol_route+0x167/0x12c0 net/ipv6/route.c:2265 ip6_pol_route_input+0x5a/0x80 net/ipv6/route.c:2322 pol_lookup_func include/net/ip6_fib.h:626 [inline] fib6_rule_lookup+0x4cc/0x6b0 net/ipv6/fib6_rules.c:117 ip6_route_input_lookup net/ipv6/route.c:2334 [inline] ip6_route_input+0x59f/0x8d0 net/ipv6/route.c:2630 ip6_rcv_finish_core net/ipv6/ip6_input.c:66 [inline] ip6_rcv_finish+0x15a/0x3c0 net/ipv6/ip6_input.c:77 NF_HOOK include/linux/netfilter.h:317 [inline] ipv6_rcv+0xed/0x220 net/ipv6/ip6_input.c:309