rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=c18c/1/0x4000000000000000 softirq=60814/60814 fqs=3 rcu: (detected by 0, t=10502 jiffies, g=46953, q=129 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12945 Comm: syz.2.1996 Not tainted 6.14.0-syzkaller-13546-g16cd1c265776 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:117 [inline] RIP: 0010:_raw_spin_lock_irq+0xb/0x50 kernel/locking/spinlock.c:170 Code: 23 f6 48 89 df 58 5b e9 c3 9e 23 f6 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 53 48 89 fb 9c 58 fa c4 02 75 30 bf 01 00 00 00 e8 56 66 14 f6 ff 74 24 08 48 8d 7b RSP: 0018:ffffc90000a08e30 EFLAGS: 00000046 RAX: 0000000000000046 RBX: ffff8880b8527840 RCX: ffffffff81a86eba RDX: ffff8880521aa440 RSI: ffffffff81a86964 RDI: ffff8880b8527840 RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffff8880b8527840 R13: 0000000000000001 R14: ffff88805bdb3340 R15: 0000000000000001 FS: 00007f5b6a2ac6c0(0000) GS:ffff888124ab3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000044466000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1765 [inline] __hrtimer_run_queues+0x2bc/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870 Code: b1 0e 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 22 34 ee 0e 0f 82 74 02 00 00 8b 35 9a 63 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 f9 b0 0e 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc900038ff188 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c1580 RCX: 00000000229baeef RDX: 0000000000000000 RSI: ffffffff8dbc95cf RDI: ffffffff8bf46580 RBP: 0000000000000002 R08: a9a6a1e1b6f5bd3a R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] is_bpf_text_address+0x36/0x1a0 kernel/bpf/core.c:772 kernel_text_address kernel/extable.c:125 [inline] kernel_text_address+0x8d/0x100 kernel/extable.c:94 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x59/0xa0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xa6/0x100 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x2d4/0x4d0 mm/slub.c:4748 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1120 __kfree_skb net/core/skbuff.c:1177 [inline] consume_skb net/core/skbuff.c:1408 [inline] consume_skb+0xcc/0x100 net/core/skbuff.c:1402 netlink_broadcast_filtered+0x3d5/0xf10 net/netlink/af_netlink.c:1524 nlmsg_multicast_filtered include/net/netlink.h:1129 [inline] nlmsg_multicast include/net/netlink.h:1148 [inline] nlmsg_notify+0x9e/0x220 net/netlink/af_netlink.c:2577 mpls_netconf_notify_devconf+0xa1/0x110 net/mpls/af_mpls.c:1201 mpls_dev_sysctl_register+0x1c9/0x2a0 net/mpls/af_mpls.c:1409 mpls_add_dev net/mpls/af_mpls.c:1460 [inline] mpls_dev_notify+0x4ab/0xa20 net/mpls/af_mpls.c:1600 notifier_call_chain+0xb9/0x410 kernel/notifier.c:85 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:2183 call_netdevice_notifiers_extack net/core/dev.c:2221 [inline] call_netdevice_notifiers net/core/dev.c:2235 [inline] register_netdevice+0x182e/0x2270 net/core/dev.c:11054 __ip_tunnel_create+0x4a8/0x680 net/ipv4/ip_tunnel.c:268 ip_tunnel_init_net+0x22f/0x7d0 net/ipv4/ip_tunnel.c:1161 ops_init+0x1df/0x5f0 net/core/net_namespace.c:138 setup_net+0x21e/0x850 net/core/net_namespace.c:364 copy_net_ns+0x2a6/0x5f0 net/core/net_namespace.c:518 create_new_namespaces+0x3ea/0xad0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:228 ksys_unshare+0x45b/0xa40 kernel/fork.c:3375 __do_sys_unshare kernel/fork.c:3446 [inline] __se_sys_unshare kernel/fork.c:3444 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3444 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5b6938d169 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:00007f5b6a2ac038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f5b695a5fa0 RCX: 00007f5b6938d169 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000006a040000 RBP: 00007f5b6940e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5b695a5fa0 R15: 00007fff70ce6f68 rcu: rcu_preempt kthread starved for 10496 jiffies! g46953 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:27848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 12930 Comm: syz.2.1990 Not tainted 6.14.0-syzkaller-13546-g16cd1c265776 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x4a5/0x1290 kernel/smp.c:885 Code: 89 ee e8 8e 12 0c 00 85 ed 74 48 48 8b 44 24 20 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 2d 17 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 de 0b 00 00 8b 43 08 31 RSP: 0018:ffffc900032877f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b853f740 RCX: ffffffff81af2709 RDX: ffff88807df28000 RSI: ffffffff81af26e3 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170a7ee9 R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b843b040 FS: 0000000000000000(0000) GS:ffff8881249b3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4de3102f98 CR3: 0000000063cf6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline] flush_tlb_mm_range+0x322/0x1780 arch/x86/mm/tlb.c:1365 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:470 [inline] tlb_flush_mmu mm/mmu_gather.c:403 [inline] tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:496 exit_mmap+0x403/0xb90 mm/mmap.c:1297 __mmput+0x12a/0x410 kernel/fork.c:1379 mmput+0x62/0x70 kernel/fork.c:1401 exit_mm kernel/exit.c:589 [inline] do_exit+0x9d1/0x2c30 kernel/exit.c:940 do_group_exit+0xd3/0x2a0 kernel/exit.c:1102 get_signal+0x2673/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7d0 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:329 [inline] irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7f5b6938d171 Code: Unable to access opcode bytes at 0x7f5b6938d147. RSP: 002b:0000200000000960 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f5b695a5fa0 RCX: 00007f5b6938d169 RDX: 0000200000000980 RSI: 0000200000000960 RDI: 0000000000080000 RBP: 00007f5b6940e2a0 R08: 0000200000000a00 R09: 0000200000000a00 R10: 00002000000009c0 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f5b695a5fa0 R15: 00007fff70ce6f68