rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6024/1:b..l P6021/1:b..l P22534/1:b..l P5664/1:b..l rcu: (detected by 1, t=10502 jiffies, g=265377, q=430 ncpus=2) task:syz-executor state:R running task stack:22888 pid:5664 tgid:5664 ppid:5657 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 f1 2d 07 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db a8 97 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ab 89 6e ff cc 48 8d 3d 88 68 92 RSP: 0018:ffffc9000314e3b8 EFLAGS: 00000286 RAX: 83b25d07e39ac500 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000c3bf0ffa RSI: ffffffff8e21de51 RDI: ffffffff8c28af60 RBP: ffffffff8176f256 R08: ffffffff8176f256 R09: ffffffff8e95cde0 R10: dffffc0000000000 R11: ffffffff81b0efc0 R12: 0000000000000002 R13: ffffffff8e95cde0 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] class_rcu_constructor include/linux/rcupdate.h:1181 [inline] unwind_next_frame+0xc3/0x2550 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5295 [inline] __kmalloc_noprof+0x35c/0x760 mm/slub.c:5307 kmalloc_noprof include/linux/slab.h:954 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] new_dir fs/proc/proc_sysctl.c:966 [inline] get_subdir fs/proc/proc_sysctl.c:1010 [inline] sysctl_mkdir_p fs/proc/proc_sysctl.c:1320 [inline] __register_sysctl_table+0xba1/0x1340 fs/proc/proc_sysctl.c:1395 neigh_sysctl_register+0x9b1/0xa90 net/core/neighbour.c:3922 devinet_sysctl_register+0xad/0x200 net/ipv4/devinet.c:2749 inetdev_init+0x2a4/0x4e0 net/ipv4/devinet.c:291 inetdev_event+0x30d/0x1610 net/ipv4/devinet.c:1590 notifier_call_chain+0x1ad/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_extack net/core/dev.c:2287 [inline] call_netdevice_notifiers net/core/dev.c:2301 [inline] register_netdevice+0x18c9/0x1ec0 net/core/dev.c:11461 veth_newlink+0x67b/0xb70 drivers/net/veth.c:1890 rtnl_newlink_create+0x329/0xb70 net/core/rtnetlink.c:3864 __rtnl_newlink net/core/rtnetlink.c:3995 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4110 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:6996 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] __sys_sendto+0x672/0x710 net/socket.c:2265 __do_sys_sendto net/socket.c:2272 [inline] __se_sys_sendto net/socket.c:2268 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2268 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f14b735d68e RSP: 002b:00007ffc1374ba68 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 000055556e206500 RCX: 00007f14b735d68e RDX: 0000000000000084 RSI: 00007f14b8144670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007ffc1374bae4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007f14b8144670 R15: 0000000000000000 task:syz-executor state:R running task stack:22424 pid:22534 tgid:22534 ppid:22512 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] copy_pte_range mm/memory.c:1331 [inline] copy_pmd_range+0x4f04/0x5970 mm/memory.c:1392 copy_pud_range mm/memory.c:1429 [inline] copy_p4d_range mm/memory.c:1453 [inline] copy_page_range+0xbe8/0x11f0 mm/memory.c:1539 dup_mmap+0xf40/0x1d90 mm/mmap.c:1840 dup_mm kernel/fork.c:1534 [inline] copy_mm+0x13b/0x4a0 kernel/fork.c:1586 copy_process+0x1f1c/0x4440 kernel/fork.c:2264 kernel_clone+0x284/0x8f0 kernel/fork.c:2721 __do_sys_clone kernel/fork.c:2862 [inline] __se_sys_clone kernel/fork.c:2846 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2846 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f792f1c58d2 RSP: 002b:00007ffef60298d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffef60298d0 RCX: 00007f792f1c58d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffef6029a5c R08: 0000000000000000 R09: 0000000000000001 R10: 0000555572e237d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000001b639d R15: 00007ffef6029ab0 task:syz.6.9801 state:R running task stack:25592 pid:6021 tgid:6021 ppid:21068 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7370 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1948 [inline] zap_pmd_range mm/memory.c:2004 [inline] zap_pud_range mm/memory.c:2032 [inline] zap_p4d_range mm/memory.c:2053 [inline] __zap_vma_range+0x3d17/0x4b40 mm/memory.c:2093 unmap_vmas+0x379/0x530 mm/memory.c:2162 exit_mmap+0x280/0x9e0 mm/mmap.c:1300 __mmput+0x118/0x430 kernel/fork.c:1178 exit_mm+0x1f6/0x2d0 kernel/exit.c:582 do_exit+0x6a2/0x22c0 kernel/exit.c:964 do_group_exit+0x21b/0x2d0 kernel/exit.c:1119 __do_sys_exit_group kernel/exit.c:1130 [inline] __se_sys_exit_group kernel/exit.c:1128 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128 x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f86cc19ce59 RSP: 002b:00007ffef4550c58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f86cc19ce59 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffef4550cbc R08: 0000000000000000 R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 000000000000031d R13: 00000000000927c0 R14: 00000000001b6334 R15: 00007ffef4550d10 task:dhcpcd-run-hook state:R running task stack:26456 pid:6024 tgid:6024 ppid:6023 task_flags:0x400040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline] irqentry_exit+0x14f/0x760 kernel/entry/common.c:164 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:56 [inline] RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline] RIP: 0010:deref_stack_reg+0x69/0x230 arch/x86/kernel/unwind_orc.c:419 Code: b9 00 4c 8b 04 24 48 be 00 00 00 00 00 fc ff df 48 89 5c 24 10 49 8b 5f 08 4d 8d 77 10 4d 89 f5 49 c1 ed 03 41 80 7c 35 00 00 <74> 16 4c 89 f7 e8 1d e8 b9 00 4c 8b 04 24 48 be 00 00 00 00 00 fc RSP: 0018:ffffc9000384ef60 EFLAGS: 00000246 RAX: fffffffffffffff0 RBX: ffffc90003848000 RCX: 0000000000000000 RDX: ffffc9000384f0c8 RSI: dffffc0000000000 RDI: ffffc9000384f088 RBP: dffffc0000000000 R08: ffffc9000384f918 R09: ffffc9000384f0d8 R10: dffffc0000000000 R11: fffff52000709e1d R12: 1ffff92000709e12 R13: 1ffff92000709e13 R14: ffffc9000384f098 R15: ffffc9000384f088 unwind_next_frame+0x19d5/0x2550 arch/x86/kernel/unwind_orc.c:-1 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 slab_free_hook mm/slub.c:2650 [inline] slab_free mm/slub.c:6250 [inline] kmem_cache_free+0x44f/0x650 mm/slub.c:6377 anon_vma_free mm/rmap.c:137 [inline] __put_anon_vma+0x12b/0x2d0 mm/rmap.c:2915 put_anon_vma mm/internal.h:216 [inline] unlink_anon_vmas+0x58b/0x730 mm/rmap.c:536 free_pgtables+0x836/0xb70 mm/memory.c:414 exit_mmap+0x490/0x9e0 mm/mmap.c:1312 __mmput+0x118/0x430 kernel/fork.c:1178 exec_mmap+0x3b4/0x440 fs/exec.c:893 begin_new_exec+0x134a/0x2480 fs/exec.c:1148 load_elf_binary+0xa47/0x2980 fs/binfmt_elf.c:1010 search_binary_handler fs/exec.c:1664 [inline] exec_binprm fs/exec.c:1696 [inline] bprm_execve+0x94a/0x1510 fs/exec.c:1748 do_execveat_common+0x50d/0x690 fs/exec.c:1846 __do_sys_execve fs/exec.c:1930 [inline] __se_sys_execve fs/exec.c:1924 [inline] __x64_sys_execve+0x97/0xc0 fs/exec.c:1924 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe675cb8107 RSP: 002b:00007fffdbee46f8 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055b10c15f078 RCX: 00007fe675cb8107 RDX: 000055b10c15f0a0 RSI: 000055b10c15f078 RDI: 000055b10c15f130 RBP: 000055b10c15f130 R08: 00007fffdbee9e6f R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 000055b10c15f0a0 R13: 00007fe675e7de8b R14: 000055b10c15f0a0 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g265377 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=113104 rcu: rcu_preempt kthread starved for 10502 jiffies! g265377 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27336 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5388 [inline] __schedule+0x1821/0x5740 kernel/sched/core.c:7189 __schedule_loop kernel/sched/core.c:7268 [inline] schedule+0x164/0x360 kernel/sched/core.c:7283 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297 kthread+0x389/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__netif_schedule+0x7/0x200 net/core/dev.c:3395 Code: 48 f8 eb bd e8 5a fc 48 f8 bb 01 00 00 00 eb db 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 <41> 56 41 55 41 54 53 50 48 89 fb 49 bd 00 00 00 00 00 fc ff df e8 RSP: 0018:ffffc90000007cf8 EFLAGS: 00000006 RAX: ffffffff89b88fbd RBX: ffffffff89b88f7b RCX: ffffffff8e692ec0 RDX: 0000000000010000 RSI: ffffffff8c28af40 RDI: ffff8880120ee000 RBP: 0000000000000001 R08: ffffffff89b88f7b R09: ffffffff8e95cde0 R10: dffffc0000000000 R11: ffffed100241dc56 R12: ffff8880543a4c00 R13: ffff8880120ee000 R14: ffff8880543a7800 R15: 18afe4c01fd47226 FS: 0000000000000000(0000) GS:ffff88812528a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055b10c14e950 CR3: 00000000b2dcd000 CR4: 0000000000350ef0 Call Trace: advance_sched+0xa3d/0xc20 net/sched/sch_taprio.c:993 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x3c0/0xa20 kernel/time/hrtimer.c:1994 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 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: bb 7d 02 e9 fe 5f 67 f5 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 13 82 20 00 fb f4 d7 5f 67 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e607dc0 EFLAGS: 00000242 RAX: 000000000089b12f RBX: ffffffff819a958a RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dfaa81a RDI: ffffffff8c28af60 RBP: ffffffff8e607eb0 R08: ffff8880b86339db R09: 1ffff110170c673b R10: dffffc0000000000 R11: ffffed10170c673c R12: 0000000000000000 R13: 1ffffffff1cd25d8 R14: 0000000000000000 R15: 1ffffffff1cd25d8 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:199 [inline] do_idle+0x36a/0x5f0 kernel/sched/idle.c:352 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:451 rest_init+0x2de/0x300 init/main.c:762 start_kernel+0x38a/0x3e0 init/main.c:1220 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