INFO: task syz.0.253:1042 blocked for more than 122 seconds. Not tainted 6.12.38-syzkaller-gc98acaeb71d4 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.0.253 state:D stack:0 pid:1042 tgid:1042 ppid:288 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 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:4657 netdev_run_todo+0x10e/0xcb0 net/core/dev.c:10868 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+0x1fe/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9bc/0x2630 kernel/exit.c:953 do_group_exit+0x22a/0x300 kernel/exit.c:1095 get_signal+0x139d/0x14f0 kernel/signal.c:2933 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: 0033:0x7faba2bc1265 RSP: 002b:00007faba3933f80 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: fffffffffffffdfc RBX: 00007faba2db5fa0 RCX: 00007faba2bc1265 RDX: 00007faba3933fc0 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007faba2c10d69 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faba2db5fa0 R15: 00007ffe9398fc58 NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 37 Comm: khungtaskd Not tainted 6.12.38-syzkaller-gc98acaeb71d4 #0 12f313afd6af6cbe2ef80fd9c185925320fe8e2c Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 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:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 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: 280 Comm: sshd-session Not tainted 6.12.38-syzkaller-gc98acaeb71d4 #0 12f313afd6af6cbe2ef80fd9c185925320fe8e2c Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x87/0x90 kernel/kcov.c:316 Code: 8d 52 28 4d 39 ca 77 22 89 ff 89 f6 49 ff c0 4c 89 01 48 c7 44 11 08 05 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 <5d> e9 13 2b 03 04 cc 66 90 b8 84 a1 7c 23 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000230770 EFLAGS: 00000246 RAX: ffffffff84ef1584 RBX: ffff88817ea9fea0 RCX: 0000000000000100 RDX: ffff88812e9cdf00 RSI: 00000000fffffffe RDI: 00000000fffffffb RBP: ffffc90000230770 R08: ffff888117b14000 R09: 0000000000000000 R10: ffffc900002308d0 R11: fffff5200004611e R12: ffff888117b140f0 R13: dffffc0000000000 R14: ffff888117b14040 R15: fffffffffffffffe FS: 00007f946f744300(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f188c8e7d60 CR3: 000000010b2a4000 CR4: 00000000003526b0 Call Trace: ip6t_do_table+0xeb4/0x14d0 net/ipv6/netfilter/ip6_tables.c:339 ip6table_mangle_hook+0x29a/0x6b0 net/ipv6/netfilter/ip6table_mangle.c:73 nf_hook_entry_hookfn include/linux/netfilter.h:155 [inline] nf_hook_slow+0xd2/0x240 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:272 [inline] NF_HOOK include/linux/netfilter.h:315 [inline] ipv6_rcv+0x1c7/0x220 net/ipv6/ip6_input.c:309 __netif_receive_skb_one_core net/core/dev.c:5757 [inline] __netif_receive_skb net/core/dev.c:5870 [inline] process_backlog+0x44b/0xae0 net/core/dev.c:6206 __napi_poll+0xd0/0x610 net/core/dev.c:6857 napi_poll net/core/dev.c:6926 [inline] net_rx_action+0x584/0xce0 net/core/dev.c:7048 handle_softirqs+0x1ab/0x630 kernel/softirq.c:621 __do_softirq+0xf/0x16 kernel/softirq.c:659 do_softirq+0xa6/0x100 kernel/softirq.c:503 __local_bh_enable_ip+0x74/0x80 kernel/softirq.c:430 local_bh_enable include/linux/bottom_half.h:33 [inline] fpregs_unlock arch/x86/include/asm/fpu/api.h:80 [inline] restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:323 [inline] __fpu_restore_sig arch/x86/kernel/fpu/signal.c:351 [inline] fpu__restore_sig+0x85f/0xf90 arch/x86/kernel/fpu/signal.c:485 restore_sigcontext arch/x86/kernel/signal_64.c:95 [inline] __ia32_sys_rt_sigreturn+0x67e/0x7a0 arch/x86/kernel/signal_64.c:268 x64_sys_call+0x2c14/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:16 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f946f080f60 Code: 48 85 f6 74 15 48 b9 00 00 00 80 01 00 00 00 48 8b 06 48 85 c8 75 33 48 89 f0 48 89 c6 41 ba 08 00 00 00 b8 0e 00 00 00 0f 05 <89> c2 f7 da 3d 00 f0 ff ff b8 00 00 00 00 0f 47 c2 48 83 c4 10 c3 RSP: 002b:00007fffbc77b8d8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 000055d4211e9420 RCX: 00007f946f080f60 RDX: 0000000000000000 RSI: 00007fffbc77b9e0 RDI: 0000000000000002 RBP: 00007fffbc77b950 R08: 000000000000013a R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fffbc77b9e0 R14: 0000000000000000 R15: 0000000000000004 net_ratelimit: 66475 callbacks suppressed bridge0: received packet on veth0_to_bridge with own address as source address (addr:46:4e:2e:4b:27:78, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:46:4e:2e:4b:27:78, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) net_ratelimit: 70912 callbacks suppressed bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:46:4e:2e:4b:27:78, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0) bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0) bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)