rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=90ac/1/0x4000000000000000 softirq=187438/187438 fqs=60 rcu: (detected by 1, t=10502 jiffies, g=220337, q=746 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6570 Comm: dhcpcd-run-hook Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__raw_callee_save___pv_queued_spin_unlock+0x10/0x18 Code: 90 90 90 90 90 90 90 90 90 90 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 e9 18 3e 00 00 56 0f b6 f0 e8 9f ff ff ff 5e 5a e9 08 3e RSP: 0018:ffffc90000007cb8 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff8880b1af92a8 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880b1af92a8 RBP: 1ffff1101635f256 R08: ffff8880b1af92ab R09: 1ffff1101635f255 R10: dffffc0000000000 R11: ffffed101635f256 R12: dffffc0000000000 R13: 1ffff1101635f257 R14: ffff8880b1af92b8 R15: ffff8880b1af92b0 FS: 0000000000000000(0000) GS:ffff888125287000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa53054a286 CR3: 0000000058200000 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+0xf5/0x210 kernel/locking/spinlock_debug.c:142 __raw_spin_unlock include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock+0x1e/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] advance_sched+0x94f/0xc20 net/sched/sch_taprio.c:988 __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:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline] RIP: 0010:anon_vma_free mm/rmap.c:112 [inline] RIP: 0010:__put_anon_vma+0x5a/0x2d0 mm/rmap.c:2915 Code: 89 f7 e8 59 92 13 00 49 8b 1e 4d 8d be 98 00 00 00 4c 89 ff be 04 00 00 00 e8 b2 94 13 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 1e 02 00 00 41 8b 2f 31 ff 89 ee e8 42 56 a8 ff 85 ed RSP: 0018:ffffc9000633f470 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffff88808872dc60 RCX: ffffffff821d729e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880595e5bf0 RBP: ffff8880a7139030 R08: ffff8880595e5bf3 R09: 1ffff1100b2bcb7e R10: dffffc0000000000 R11: ffffed100b2bcb7f R12: dffffc0000000000 R13: 1ffff1100b2bcb6b R14: ffff8880595e5b58 R15: ffff8880595e5bf0 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: 0033:0x7fa530490107 Code: Unable to access opcode bytes at 0x7fa5304900dd. RSP: 002b:00007fff61a8f538 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 0000564b4a2121b8 RCX: 00007fa530490107 RDX: 0000564b4a2121d8 RSI: 0000564b4a2121b8 RDI: 0000564b4a212288 RBP: 0000564b4a212288 R08: 00007fff61a93d10 R09: 0000000000000000 R10: 0000000000000008 R11: 0000000000000246 R12: 0000564b4a2121d8 R13: 00007fa530655e8b R14: 0000564b4a2121d8 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10157 jiffies! g220337 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:27544 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: 1 UID: 0 PID: 5562 Comm: udevd 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+0xfcf/0x13d0 kernel/smp.c:892 Code: 79 45 8b 2e 44 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 RSP: 0000:ffffc9000e38f840 EFLAGS: 00000293 RAX: ffffffff81b9c2b6 RBX: ffff8880b873c148 RCX: ffff8880323e1ec0 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000e38f970 R08: ffffffff9030d4f7 R09: 1ffffffff2061a9e R10: dffffc0000000000 R11: fffffbfff2061a9f R12: 1ffff110170c8589 R13: dffffc0000000000 R14: ffff8880b8642c48 R15: 0000000000000000 FS: 00007f105146a880(0000) GS:ffff888125387000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d2b3d45f28 CR3: 00000000a716c000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451 flush_tlb_page arch/x86/include/asm/tlbflush.h:345 [inline] ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:104 wp_page_copy mm/memory.c:3941 [inline] do_wp_page+0x3da7/0x4cc0 mm/memory.c:4336 handle_pte_fault mm/memory.c:6443 [inline] __handle_mm_fault mm/memory.c:6565 [inline] handle_mm_fault+0x151f/0x3170 mm/memory.c:6734 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f1050cb5b69 Code: 10 48 81 f9 ff 03 00 00 76 28 48 8b 57 20 48 85 d2 74 1f 48 3b 7a 28 75 76 48 8b 4f 28 48 3b 79 20 75 6c 48 83 78 20 00 74 17 <48> 89 4a 28 48 89 51 20 48 83 c4 08 c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe857a7a00 EFLAGS: 00010202 RAX: 00007f1050df2260 RBX: 0000000000007da0 RCX: 000055d2b3d45f00 RDX: 000055d2b3d45f00 RSI: 00007f1050df2260 RDI: 000055d2b3d45f00 RBP: 00007f1050df1ac0 R08: 0000000000007da0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055d2b3d41540 R13: 00007f1050df1ac0 R14: 0000000000007da0 R15: 00007f1050df1ac0