rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (3 ticks this GP) idle=57c4/1/0x4000000000000000 softirq=14657/14657 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=11005, q=1193 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 30 Comm: kauditd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__lock_acquire+0x4be/0x1a40 kernel/locking/lockdep.c:5207 Code: 48 89 de 48 89 ef e8 f1 ee ff ff 85 c0 0f 84 e9 fe ff ff 44 8b 1d a2 d9 8d 19 45 85 db 75 11 4d 63 e4 4c 0f a3 25 72 2d 85 14 <0f> 83 69 0b 00 00 48 8b b5 90 0b 00 00 45 85 ed 0f 84 93 01 00 00 RSP: 0018:ffffc90000007d48 EFLAGS: 00000047 RAX: 0000000000000001 RBX: ffff88801f6ed620 RCX: 0000000000000100 RDX: 0000000000000000 RSI: ffff88801f6ed620 RDI: ffff88801f6eca80 RBP: ffff88801f6eca80 R08: 0000000000000001 R09: 0000000000000002 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000071 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888123ddc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f15131eb158 CR3: 0000000061fa4000 CR4: 00000000003526f0 Call Trace: lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5825 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:174 __run_hrtimer kernel/time/hrtimer.c:2036 [inline] __hrtimer_run_queues+0x1b7/0x9c0 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:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3270 Code: 00 e8 91 24 2a 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 df d0 21 00 48 85 ed 0f 85 d7 01 00 00 e8 31 d6 21 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b RSP: 0018:ffffc90000a67980 EFLAGS: 00000293 RAX: ffffffff8f9ac7d8 RBX: ffffffff8f9ac780 RCX: ffffffff81e88a01 RDX: ffff88801f6eca80 RSI: ffffffff81e88a0f RDI: ffff88801f6eca80 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000009fb R13: ffffffff8f9ac7d8 R14: ffffc90000a67a00 R15: dffffc0000000000 console_flush_all kernel/printk/printk.c:3343 [inline] __console_flush_and_unlock kernel/printk/printk.c:3373 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3413 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2479 _printk+0xcf/0x110 kernel/printk/printk.c:2504 kauditd_printk_skb kernel/audit.c:588 [inline] kauditd_hold_skb.cold+0x3f/0x4e kernel/audit.c:623 kauditd_send_queue+0x232/0x2e0 kernel/audit.c:808 kauditd_thread+0x645/0xb30 kernel/audit.c:932 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: rcu_preempt kthread starved for 8840 jiffies! g11005 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:28824 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: 1 UID: 0 PID: 5606 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:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:write_comp_data+0x3a/0x90 kernel/kcov.c:246 Code: 65 48 8b 3d 10 e7 59 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 e9 40 f8 b3 09 8b 87 24 17 00 00 85 c0 74 f1 <8b> 87 f8 16 00 00 83 f8 03 75 e6 48 8b 87 00 17 00 00 8b bf fc 16 RSP: 0018:ffffc9000453f628 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81fdc702 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88807e21ca80 RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 0000000000000000(0000) GS:ffff888123edc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f802fbf0000 CR3: 000000002b222000 CR4: 00000000003526f0 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0x5b2/0x1870 kernel/smp.c:912 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1077 __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+0x45f/0x16f0 arch/x86/mm/tlb.c:1451 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:499 [inline] tlb_flush_mmu mm/mmu_gather.c:423 [inline] tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549 exit_mmap+0x454/0xa00 mm/mmap.c:1313 __mmput+0x12a/0x410 kernel/fork.c:1187 mmput+0x67/0x80 kernel/fork.c:1210 exit_mm kernel/exit.c:615 [inline] do_exit+0x8b1/0x2ae0 kernel/exit.c:997 do_group_exit+0xd5/0x2a0 kernel/exit.c:1152 get_signal+0x1ec7/0x21e0 kernel/signal.c:3046 arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x139/0x6f0 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x666/0x870 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f1512f5e6ce Code: Unable to access opcode bytes at 0x7f1512f5e6a4. RSP: 002b:00007ffe44d240e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: fffffffffffffe00 RBX: 0000555574414500 RCX: 00007f1512f5e6ce RDX: 0000000000000030 RSI: 00007ffe44d241e0 RDI: 00000000000000f9 RBP: 00007ffe44d2418c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 0000000000011b44 R15: 00007ffe44d241e0 sched: DL replenish lagged too much