rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 GPs behind) idle=9954/1/0x4000000000000000 softirq=64697/64698 fqs=2 rcu: (detected by 1, t=10505 jiffies, g=75521, q=418 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12874 Comm: syz.1.2086 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:kasan_check_range+0xfc/0x1e0 mm/kasan/generic.c:201 Code: c0 01 48 39 c2 74 1d 80 38 00 74 f2 ba 01 00 00 00 48 85 c0 74 2c 41 83 e2 07 49 39 c1 75 15 45 3a 11 7d 10 ba 01 00 00 00 5b <5d> 89 d0 41 5c e9 4a 7a 41 09 41 0f b6 d0 e8 e1 e6 ff ff 83 f0 01 RSP: 0018:ffffc90000007ce0 EFLAGS: 00000046 RAX: fffffbfff3721e9d RBX: ffffffff9b90f4e0 RCX: ffffffff81e63659 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffffff9b90f4e0 RBP: fffffbfff3721e9c R08: 0000000000000001 R09: fffffbfff3721e9c R10: ffffffff9b90f4e3 R11: 0000000000000000 R12: 1ffff92000000fa0 R13: ffffffff9b90f4f0 R14: ffff88807b787300 R15: 1ffff92000000fb8 FS: 00007fd1b1c586c0(0000) GS:ffff888123ded000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32712ff8 CR3: 00000000345de000 CR4: 00000000003526f0 Call Trace: instrument_atomic_read_write include/linux/instrumented.h:112 [inline] atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1300 [inline] queued_spin_lock include/asm-generic/qspinlock.h:111 [inline] do_raw_spin_lock+0x119/0x260 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock_irqsave+0x42/0x60 kernel/locking/spinlock.c:166 debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:936 debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline] __run_hrtimer kernel/time/hrtimer.c:2000 [inline] __hrtimer_run_queues+0x2e9/0x9c0 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 51 27 2a 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 3f d3 21 00 48 85 ed 0f 85 d7 01 00 00 e8 91 d8 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:ffffc900053a7450 EFLAGS: 00000283 RAX: ffffffff8f9aa758 RBX: ffffffff8f9aa700 RCX: ffffc9000cbd1000 RDX: 0000000000080000 RSI: ffffffff81e87c4f RDI: ffff888027b48000 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000035ee R13: ffffffff8f9aa758 R14: ffffc900053a74d0 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 set_target_expiration arch/x86/kvm/lapic.c:2174 [inline] __start_apic_timer.cold+0xf4/0x152 arch/x86/kvm/lapic.c:2392 kvm_apic_set_state+0x540/0xa70 arch/x86/kvm/lapic.c:3333 kvm_vcpu_ioctl_set_lapic arch/x86/kvm/x86.c:5318 [inline] kvm_arch_vcpu_ioctl+0x3bd/0x57a0 arch/x86/kvm/x86.c:6235 kvm_vcpu_ioctl+0x8a0/0x1700 virt/kvm/kvm_main.c:4647 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7fd1b0d9e0d9 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:00007fd1b1c58028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd1b1025fa0 RCX: 00007fd1b0d9e0d9 RDX: 0000200000000040 RSI: 000000004400ae8f RDI: 0000000000000008 RBP: 00007fd1b0e35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1b1026038 R14: 00007fd1b1025fa0 R15: 00007ffdbc85ac28 rcu: rcu_preempt kthread starved for 10495 jiffies! g75521 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: 11173 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:get_current arch/x86/include/asm/current.h:23 [inline] RIP: 0010:write_comp_data+0x10/0x90 kernel/kcov.c:245 Code: 6d fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 8b 05 99 e2 58 12 49 89 f8 49 89 f1 49 89 d2 <65> 48 8b 3d 70 e2 58 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 RSP: 0018:ffffc90004fbf5f0 EFLAGS: 00000202 RAX: 0000000000000002 RBX: 0000000000000000 RCX: ffffffff81fdb952 RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000005 RBP: ffffe8ffffc29d80 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: fffff91ffff853b1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 0000555585bbe500(0000) GS:ffff888123eed000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3112b556c8 CR3: 000000007638c000 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 dup_mmap+0x1307/0x21b0 mm/mmap.c:1905 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: 0033:0x7f3111dc6b52 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:00007ffebb7b2a60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffebb7b2a60 RCX: 00007f3111dc6b52 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffebb7b2bec R08: 0000000000000000 R09: 0000000000000001 R10: 0000555585bbe7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000063 R14: 00000000000966af R15: 00007ffebb7b2c40 watchdog: BUG: soft lockup - CPU#1 stuck for 246s! [syz-executor:11173] Modules linked in: irq event stamp: 1520314 hardirqs last enabled at (1520313): [] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline] hardirqs last enabled at (1520313): [] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:542 [inline] hardirqs last enabled at (1520313): [] irqentry_exit+0x24d/0xa00 kernel/entry/common.c:167 hardirqs last disabled at (1520314): [] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1062 softirqs last enabled at (1520312): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last enabled at (1520312): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last enabled at (1520312): [] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 softirqs last disabled at (1520239): [] __do_softirq kernel/softirq.c:656 [inline] softirqs last disabled at (1520239): [] invoke_softirq kernel/softirq.c:496 [inline] softirqs last disabled at (1520239): [] __irq_exit_rcu+0x162/0x210 kernel/softirq.c:735 CPU: 1 UID: 0 PID: 11173 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP 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 b4 9b 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:ffffc90004fbf5f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fdb952 RDX: ffff88802d66a540 RSI: ffffffff81fdb92c RDI: ffff88802d66a540 RBP: ffffe8ffffc29d80 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003 R13: fffff91ffff853b1 R14: 0000000000000001 R15: ffff8880b853c880 FS: 0000555585bbe500(0000) GS:ffff888123eed000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3112b556c8 CR3: 000000007638c000 CR4: 00000000003526f0 Call Trace: 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 dup_mmap+0x1307/0x21b0 mm/mmap.c:1905 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: 0033:0x7f3111dc6b52 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:00007ffebb7b2a60 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffebb7b2a60 RCX: 00007f3111dc6b52 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffebb7b2bec R08: 0000000000000000 R09: 0000000000000001 R10: 0000555585bbe7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000063 R14: 00000000000966af R15: 00007ffebb7b2c40 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 12874 Comm: syz.1.2086 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:__sanitizer_cov_trace_pc+0xb/0x70 kernel/kcov.c:213 Code: 64 00 be 03 00 00 00 5b e9 22 bb 12 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 45 db 58 12 <48> 8b 34 24 65 48 8b 15 21 db 58 12 a9 00 01 ff 00 74 1b f6 c4 01 RSP: 0018:ffffc90000007e60 EFLAGS: 00000002 RAX: 0000000000010002 RBX: ffff8880b8428640 RCX: ffffffff81f5d358 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888027b48000 RBP: ffff88807b787300 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: ffff8880b8428690 FS: 00007fd1b1c586c0(0000) GS:ffff888123ded000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32712ff8 CR3: 00000000345de000 CR4: 00000000003526f0 Call Trace: enqueue_hrtimer+0x223/0x2f0 kernel/time/hrtimer.c:1107 __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:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3270 Code: 00 e8 51 27 2a 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 3f d3 21 00 48 85 ed 0f 85 d7 01 00 00 e8 91 d8 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:ffffc900053a7450 EFLAGS: 00000283 RAX: ffffffff8f9aa758 RBX: ffffffff8f9aa700 RCX: ffffc9000cbd1000 RDX: 0000000000080000 RSI: ffffffff81e87c4f RDI: ffff888027b48000 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 00000000000035ee R13: ffffffff8f9aa758 R14: ffffc900053a74d0 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 set_target_expiration arch/x86/kvm/lapic.c:2174 [inline] __start_apic_timer.cold+0xf4/0x152 arch/x86/kvm/lapic.c:2392 kvm_apic_set_state+0x540/0xa70 arch/x86/kvm/lapic.c:3333 kvm_vcpu_ioctl_set_lapic arch/x86/kvm/x86.c:5318 [inline] kvm_arch_vcpu_ioctl+0x3bd/0x57a0 arch/x86/kvm/x86.c:6235 kvm_vcpu_ioctl+0x8a0/0x1700 virt/kvm/kvm_main.c:4647 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7fd1b0d9e0d9 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:00007fd1b1c58028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd1b1025fa0 RCX: 00007fd1b0d9e0d9 RDX: 0000200000000040 RSI: 000000004400ae8f RDI: 0000000000000008 RBP: 00007fd1b0e35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd1b1026038 R14: 00007fd1b1025fa0 R15: 00007ffdbc85ac28