INFO: task syz.3.1985:9350 blocked for more than 143 seconds. Not tainted 6.1.143-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.3.1985 state:D stack:22976 pid:9350 ppid:4269 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 perf_pending_task_sync kernel/events/core.c:5031 [inline] _free_event+0x171/0x10a0 kernel/events/core.c:5037 put_event kernel/events/core.c:5162 [inline] perf_event_release_kernel+0x832/0x8c0 kernel/events/core.c:5287 perf_release+0x37/0x40 kernel/events/core.c:5297 __fput+0x22c/0x920 fs/file_table.c:320 task_work_run+0x1ca/0x250 kernel/task_work.c:203 get_signal+0x11a6/0x1350 kernel/signal.c:2648 arch_do_signal_or_restart+0xb0/0x1230 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 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+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f638878e929 RSP: 002b:00007f63896a8fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: fffffffffffffffc RBX: 00007f63889b5fa0 RCX: 00007f638878e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000 RBP: 00007f6388810b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f63889b5fa0 R15: 00007ffd248b5b58 Showing all locks held in the system: 3 locks held by kworker/0:0/7: #0: ffff888017470938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc900000c7d00 ((work_completion)(&data->fib_event_work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffff888058c70240 (&data->fib_lock){+.+.}-{3:3}, at: nsim_fib_event_work+0x26b/0x32b0 drivers/net/netdevsim/fib.c:1491 3 locks held by kworker/u4:0/9: 1 lock held by rcu_tasks_kthre/12: #0: ffffffff8cb2b430 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by rcu_tasks_trace/13: #0: ffffffff8cb2bc50 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x33/0xf00 kernel/rcu/tasks.h:517 1 lock held by khungtaskd/27: #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2aaa0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x290 kernel/locking/lockdep.c:6513 2 locks held by getty/4032: #0: ffff88814c9c1098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:244 #1: ffffc9000327b2f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x41b/0x1380 drivers/tty/n_tty.c:2198 3 locks held by kworker/0:6/4318: #0: ffff88803050bd38 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #1: ffffc90004d27d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267 #2: ffffffff8dd419a8 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xc4/0x14d0 net/ipv6/addrconf.c:4137 4 locks held by syz.7.2346/10957: 1 lock held by syz-executor/10974: #0: ffffffff8dd419a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock net/core/rtnetlink.c:74 [inline] #0: ffffffff8dd419a8 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x740/0xed0 net/core/rtnetlink.c:6150 1 lock held by syz.8.2366/11005: #0: ffffffff8dd419a8 (rtnl_mutex){+.+.}-{3:3}, at: ppp_release+0x86/0x1f0 drivers/net/ppp/ppp_generic.c:417 2 locks held by syz.6.2356/11007: #0: ffffffff8dd34d10 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:504 #1: ffffffff8dd419a8 (rtnl_mutex){+.+.}-{3:3}, at: ip_tunnel_init_net+0x281/0x740 net/ipv4/ip_tunnel.c:1117 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 27 Comm: khungtaskd Not tainted 6.1.143-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 nmi_cpu_backtrace+0x3f4/0x470 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1d4/0x450 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+0xeee/0xf30 kernel/hung_task.c:377 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10957 Comm: syz.7.2346 Not tainted 6.1.143-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 af b2 f8 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000007e38 EFLAGS: 00000046 RAX: 000000000000003e RBX: 000000000000003e RCX: 0000000000000838 RDX: 0000000000000000 RSI: 000000000000003e RDI: 0000000000000838 RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1c3ec16 R10: fffffbfff1c3ec16 R11: 1ffffffff1c3ec15 R12: dffffc0000000000 R13: 0000000010004d2c R14: ffffffff8c5e3b30 R15: dffffc0000000000 FS: 00007f19d07ff6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f224637f2d8 CR3: 000000004263e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:478 clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x59d/0x9c0 kernel/time/hrtimer.c:1891 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__sanitizer_cov_trace_pc+0x41/0x60 kernel/kcov.c:221 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b 91 00 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 fc 15 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc90003597248 EFLAGS: 00000246 RAX: ffffffff8139444d RBX: ffff888056974000 RCX: ffff8880259a8000 RDX: ffffc9001c26b000 RSI: 000000000007ffff RDI: ffff888056974000 RBP: dffffc0000000000 R08: dffffc0000000000 R09: fffffbfff1c3ec16 R10: fffffbfff1c3ec16 R11: 1ffffffff1c3ec15 R12: ffff8880559ebe3e R13: ffff8880559ebdc0 R14: ffff8880569742c0 R15: dffffc0000000000 __phys_addr+0xd/0x170 arch/x86/mm/physaddr.c:16 virt_to_head_page include/linux/mm.h:895 [inline] page_frag_free+0x14/0x150 mm/page_alloc.c:5839 skb_free_frag include/linux/skbuff.h:3241 [inline] skb_free_head net/core/skbuff.c:760 [inline] skb_release_data+0x646/0x7c0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] kfree_skb_reason+0x163/0x370 net/core/skbuff.c:893 kfree_skb include/linux/skbuff.h:1220 [inline] napi_free_frags include/linux/netdevice.h:3888 [inline] napi_get_frags_check+0x5f/0x90 net/core/skbuff.c:217 netif_napi_add_weight+0x9c0/0xdb0 net/core/dev.c:6472 netif_napi_add include/linux/netdevice.h:2596 [inline] gro_cells_init+0x199/0x250 net/core/gro_cells.c:84 ip_tunnel_init+0x20c/0x400 net/ipv4/ip_tunnel.c:1286 register_netdevice+0x65b/0x1aa0 net/core/dev.c:10118 __ip_tunnel_create+0x33e/0x440 net/ipv4/ip_tunnel.c:267 ip_tunnel_init_net+0x28f/0x740 net/ipv4/ip_tunnel.c:1118 vti_init_net+0x2b/0xf0 net/ipv4/ip_vti.c:504 ops_init+0x355/0x5f0 net/core/net_namespace.c:138 setup_net+0x4e1/0xbb0 net/core/net_namespace.c:336 copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:508 create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110 copy_namespaces+0x3b0/0x410 kernel/nsproxy.c:178 copy_process+0x199c/0x4020 kernel/fork.c:2354 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2882 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f19d098e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f19d07fefe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007f19d0bb5fa0 RCX: 00007f19d098e929 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000640c7000 RBP: 00007f19d0a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f19d0bb5fa0 R15: 00007ffe0ce9f3e8