rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=df84/1/0x4000000000000000 softirq=43933/43933 fqs=1 rcu: (detected by 0, t=10505 jiffies, g=44429, q=514 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5625 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x12/0x18 Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 52 b8 01 00 00 00 31 d2 f0 0f b0 17 75 06 <5a> c3 cc cc cc cc 56 0f b6 f0 e8 9f ff ff ff 5e 5a c3 cc cc cc cc RSP: 0018:ffffc90000a08d28 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffffffff9b9bd1a8 RCX: ffffffff81e64813 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff9b9bd1a8 RBP: ffffffff9b9bd1b0 R08: 0000000000000000 R09: fffffbfff3737a35 R10: ffffffff9b9bd1ab R11: 0000000000000000 R12: ffffffff9b9bd1b8 R13: ffff88807db5e300 R14: dffffc0000000000 R15: 1ffff920001411b2 FS: 000055558108e500(0000) GS:ffff888123eda000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb6c85556c8 CR3: 0000000059bd3000 CR4: 00000000003526f0 Call Trace: pv_queued_spin_unlock arch/x86/include/asm/paravirt-spinlock.h:40 [inline] queued_spin_unlock arch/x86/include/asm/paravirt-spinlock.h:72 [inline] do_raw_spin_unlock+0x145/0x1e0 kernel/locking/spinlock_debug.c:142 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:177 [inline] _raw_spin_unlock_irqrestore+0x22/0x80 kernel/locking/spinlock.c:198 debug_object_activate+0x343/0x4b0 lib/debugobjects.c:891 debug_hrtimer_activate kernel/time/hrtimer.c:485 [inline] debug_activate kernel/time/hrtimer.c:528 [inline] enqueue_hrtimer+0x75/0x2f0 kernel/time/hrtimer.c:1109 __run_hrtimer kernel/time/hrtimer.c:2048 [inline] __hrtimer_run_queues+0x6ed/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_is_held_type+0xf5/0x140 kernel/locking/lockdep.c:5945 Code: ff ff ff ff 65 0f c1 15 19 f5 a8 08 83 fa 01 8b 44 24 04 75 2d 9c 5a 80 e6 02 75 47 41 f7 c5 00 02 00 00 74 01 fb 48 83 c4 08 <5b> 5d 41 5c 41 5d 41 5e 41 5f e9 fc 40 03 00 c3 cc cc cc cc 31 c0 RSP: 0018:ffffc90002f6f3f0 EFLAGS: 00000296 RAX: 0000000000000001 RBX: ffffffff8ebe8200 RCX: 0000000000000001 RDX: 0000000000000046 RSI: ffffffff8e1817ed RDI: ffffffff8c402680 RBP: ffff88807aa80000 R08: 0000000000000006 R09: 0000000000001000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000ffffffff R13: 0000000000000246 R14: ffff88807aa80c18 R15: 0000000000000003 lookup_page_ext+0x6e/0x100 mm/page_ext.c:258 page_ext_iter_begin include/linux/page_ext.h:137 [inline] page_table_check_set+0x314/0x930 mm/page_table_check.c:113 __page_table_check_ptes_set+0x27a/0x4e0 mm/page_table_check.c:212 page_table_check_ptes_set include/linux/page_table_check.h:83 [inline] set_ptes include/linux/pgtable.h:447 [inline] __copy_present_ptes mm/memory.c:1118 [inline] copy_present_ptes mm/memory.c:1197 [inline] copy_pte_range mm/memory.c:1320 [inline] copy_pmd_range mm/memory.c:1408 [inline] copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0x2197/0x5b20 mm/memory.c:1555 dup_mmap+0xd44/0x21b0 mm/mmap.c:1840 dup_mm kernel/fork.c:1543 [inline] copy_mm kernel/fork.c:1595 [inline] copy_process+0x4588/0x8030 kernel/fork.c:2289 kernel_clone+0x176/0x9d0 kernel/fork.c:2748 __do_sys_clone+0xd9/0x120 kernel/fork.c:2889 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb6c77c6a92 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:00007ffd431f38c0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd431f38c0 RCX: 00007fb6c77c6a92 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd431f3a4c R08: 0000000000000000 R09: 0000000000000001 R10: 000055558108e7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000049394 R15: 00007ffd431f3aa0 rcu: rcu_preempt kthread starved for 10500 jiffies! g44429 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:26344 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 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: 10011 Comm: syz.2.1227 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0x58e/0x1870 kernel/smp.c:912 Code: b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 64 99 0c 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 a8 10 00 00 8b 45 08 31 RSP: 0018:ffffc90005aa7840 EFLAGS: 00000246 RAX: 0000000000080000 RBX: 0000000000000001 RCX: ffffc9000de7a000 RDX: 0000000000080000 RSI: ffffffff81fdc79c RDI: ffff88807e6a2540 RBP: ffff8880b8541240 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170a8249 R14: 0000000000000001 R15: ffff8880b843c880 FS: 00007f39890d86c0(0000) GS:ffff888123dda000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b33920ff8 CR3: 000000007562f000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077 bpf_prog_pack_alloc+0x2d9/0x8c0 kernel/bpf/core.c:1022 bpf_jit_binary_pack_alloc+0xab/0x2b0 kernel/bpf/core.c:1202 bpf_int_jit_compile+0x531/0x1790 arch/x86/net/bpf_jit_comp.c:3966 bpf_prog_jit_compile kernel/bpf/core.c:2627 [inline] __bpf_prog_select_runtime+0x8ac/0xc50 kernel/bpf/core.c:2696 bpf_migrate_filter net/core/filter.c:1318 [inline] bpf_prepare_filter+0xd3f/0x11e0 net/core/filter.c:1366 bpf_prog_create_from_user+0x1e8/0x2f0 net/core/filter.c:1460 seccomp_prepare_filter kernel/seccomp.c:701 [inline] seccomp_prepare_user_filter kernel/seccomp.c:738 [inline] seccomp_set_mode_filter kernel/seccomp.c:1990 [inline] do_seccomp+0x870/0x27d0 kernel/seccomp.c:2110 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f398819e019 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:00007f39890d8028 EFLAGS: 00000246 ORIG_RAX: 000000000000013d RAX: ffffffffffffffda RBX: 00007f3988425fa0 RCX: 00007f398819e019 RDX: 0000200000000040 RSI: 0000000000000000 RDI: 0000000000000001 RBP: 00007f398823500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3988426038 R14: 00007f3988425fa0 R15: 00007ffc2bad1398