rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=c054/1/0x4000000000000000 softirq=74944/74944 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=70909, q=1194 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5623 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:146 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:153 [inline] RIP: 0010:lock_acquire+0x12e/0x350 kernel/locking/lockdep.c:5871 Code: 00 00 48 83 c4 28 48 c7 c7 cb 49 22 8e e8 4a ab 08 0a b8 ff ff ff ff 65 0f c1 05 5d ef 98 11 83 f8 01 0f 85 ae 00 00 00 9c 58 00 02 00 00 0f 85 c1 00 00 00 f7 44 24 08 00 02 00 00 0f 85 c6 RSP: 0018:ffffc90000a08c60 EFLAGS: 00000046 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000010003 RDX: 00000000393acb00 RSI: ffffffff8e2249cb RDI: ffffffff8c28afe0 RBP: ffffffff89b89fa4 R08: ffffffff89b89fa4 R09: ffff88803474d2c0 R10: dffffc0000000000 R11: ffffffff89b89ef0 R12: 0000000000000000 R13: ffff88803474d2c0 R14: 0000000000000001 R15: 0000000000000046 FS: 0000555574e72500(0000) GS:ffff88812537a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5d641456b8 CR3: 00000000676e8000 CR4: 00000000003526f0 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158 spin_lock include/linux/spinlock.h:342 [inline] advance_sched+0xb4/0xc20 net/sched/sch_taprio.c:930 __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:kasan_check_byte include/linux/kasan.h:402 [inline] RIP: 0010:lock_acquire+0x7c/0x350 kernel/locking/lockdep.c:5842 Code: a3 05 68 66 8f 0e 73 0d e8 11 28 09 00 84 c0 0f 84 ca 01 00 00 83 3d 22 99 8f 0e 00 0f 84 d3 00 00 00 48 8b b4 24 90 00 00 00 <4c> 89 ef e8 1c 22 8f 00 83 3d 05 99 8f 0e 00 0f 84 ce 00 00 00 65 RSP: 0018:ffffc9000400f208 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000080000003 RDX: 0000000000000000 RSI: ffffffff823c9d23 RDI: ffffffff8c28af80 RBP: ffffffff823c9d06 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff94000366ee1 R12: 0000000000000002 R13: ffffffff8e95cda0 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] page_table_check_set+0x143/0x510 mm/page_table_check.c:112 page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:413 [inline] __copy_present_ptes mm/memory.c:1102 [inline] copy_present_ptes mm/memory.c:1181 [inline] copy_pte_range mm/memory.c:1304 [inline] copy_pmd_range+0x486a/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: 0033:0x7f5d633c58d2 Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc82ca0a90 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc82ca0a90 RCX: 00007f5d633c58d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc82ca0c1c R08: 0000000000000000 R09: 0000000000000001 R10: 0000555574e727d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000059ae2 R15: 00007ffc82ca0c70 rcu: rcu_preempt kthread starved for 10502 jiffies! g70909 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:27536 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: CPU: 0 UID: 0 PID: 17449 Comm: syz.4.2857 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xfd4/0x13d0 kernel/smp.c:892 Code: 89 ee 83 e6 01 31 ff e8 7a 06 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 02 0c 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 0a 02 0c 00 eb e5 44 89 RSP: 0018:ffffc90005976900 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8880b863c148 RCX: 0000000000080000 RDX: ffffc9000ccf9000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90005976a40 R08: ffffffff90311bf7 R09: 1ffffffff206237e R10: dffffc0000000000 R11: fffffbfff206237f R12: 1ffff110170e8169 R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001 FS: 00007f4f015f76c0(0000) GS:ffff88812527a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34514ff8 CR3: 000000007dbd8000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 on_each_cpu include/linux/smp.h:72 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline] smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2983 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 __static_key_slow_dec_cpuslocked+0xbb/0x110 kernel/jump_label.c:315 __static_key_slow_dec kernel/jump_label.c:321 [inline] static_key_slow_dec+0x45/0x90 kernel/jump_label.c:336 unblock_netpoll_tx include/net/bonding.h:100 [inline] bond_enslave+0x22a5/0x3c10 drivers/net/bonding/bond_main.c:2287 do_set_master+0x533/0x6d0 net/core/rtnetlink.c:2999 rtnl_newlink_create+0x6af/0xb70 net/core/rtnetlink.c:3891 __rtnl_newlink net/core/rtnetlink.c:4008 [inline] rtnl_newlink+0x166a/0x1bb0 net/core/rtnetlink.c:4123 rtnetlink_rcv_msg+0x7d5/0xbe0 net/core/rtnetlink.c:7009 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2551 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1895 sock_sendmsg_nosec net/socket.c:787 [inline] __sock_sendmsg net/socket.c:802 [inline] ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752 __sys_sendmsg net/socket.c:2784 [inline] __do_sys_sendmsg net/socket.c:2789 [inline] __se_sys_sendmsg net/socket.c:2787 [inline] __x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787 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: 0033:0x7f4f0079ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f4f015f7028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f4f00a15fa0 RCX: 00007f4f0079ce59 RDX: 00000000000440b0 RSI: 0000200000000280 RDI: 0000000000000004 RBP: 00007f4f00832d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4f00a16038 R14: 00007f4f00a15fa0 R15: 00007ffd612506c8