rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (0 ticks this GP) idle=1d84/1/0x4000000000000000 softirq=264313/264313 fqs=0 rcu: (detected by 0, t=10502 jiffies, g=273381, q=226 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 25261 Comm: syz.1.23520 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:advance_sched+0x94a/0xc90 net/sched/sch_taprio.c:-1 Code: 89 df 49 8d 5c 24 80 48 83 c5 10 48 89 e8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 48 89 ef e8 26 f3 a4 f8 <4c> 8b 74 24 20 4c 89 75 00 48 89 df 4c 89 fe 48 8b 54 24 08 e8 3d RSP: 0018:ffffc90000a08c70 EFLAGS: 00000046 RAX: 1ffff110043e7c2a RBX: ffff88804ad602c0 RCX: dffffc0000000000 RDX: 0000000000010000 RSI: 0000000004000000 RDI: 0000000000000000 RBP: ffff888021f3e150 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: ffff88804ad60340 R13: ffff88804ad60000 R14: ffff888021f3e008 R15: ffff888021f3c800 FS: 0000000000000000(0000) GS:ffff888125d99000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3e8105 CR3: 000000000df36000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 db 48 fa 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003b8f4d8 EFLAGS: 00000206 RAX: 9e1bfb61fd350800 RBX: 0000000000000000 RCX: 9e1bfb61fd350800 RDX: 0000000000000000 RSI: ffffffff8db46f77 RDI: ffffffff8be19200 RBP: ffffffff822c66ea R08: 0000000000000000 R09: ffffffff822c66ea R10: dffffc0000000000 R11: fffff94000310739 R12: 0000000000000002 R13: ffffffff8e13cd40 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock_sched include/linux/rcupdate.h:932 [inline] pfn_valid+0xd6/0x490 include/linux/mmzone.h:2116 page_table_check_clear+0x21/0x700 mm/page_table_check.c:70 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1501 [inline] zap_present_ptes mm/memory.c:1586 [inline] do_zap_pte_range mm/memory.c:1687 [inline] zap_pte_range mm/memory.c:1731 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x32fd/0x4580 mm/memory.c:1894 unmap_vmas+0x25d/0x3c0 mm/memory.c:1984 exit_mmap+0x245/0xba0 mm/mmap.c:1284 __mmput+0x118/0x420 kernel/fork.c:1381 exit_mm+0x1da/0x2c0 kernel/exit.c:595 do_exit+0x864/0x2550 kernel/exit.c:947 do_group_exit+0x21c/0x2d0 kernel/exit.c:1108 __do_sys_exit_group kernel/exit.c:1119 [inline] __se_sys_exit_group kernel/exit.c:1117 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1117 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb9d8b8e969 Code: Unable to access opcode bytes at 0x7fb9d8b8e93f. RSP: 002b:00007fffac480328 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9d8b8e969 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fffac48038c R08: 00000005ac48041f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 00000000000012b8 R13: 00000000000927c0 R14: 0000000000175cb9 R15: 00007fffac4803e0 rcu: rcu_preempt kthread starved for 10502 jiffies! g273381 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:26856 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5392 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6781 __schedule_loop kernel/sched/core.c:6859 [inline] schedule+0x165/0x360 kernel/sched/core.c:6874 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 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: 25268 Comm: syz.9.23521 Not tainted 6.15.0-syzkaller-09113-g8477ab143069 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x46/0x70 kernel/kcov.c:222 Code: ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 <48> 8d 7e 01 8b 89 1c 16 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 RSP: 0018:ffffc90004b57ab8 EFLAGS: 00000246 RAX: ffffffff81b4c990 RBX: ffff8880b863ca80 RCX: ffff888027000000 RDX: ffffc9000f7d3000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc90004b57c20 R08: ffffffff8f9f7ef7 R09: 1ffffffff1f3efde R10: dffffc0000000000 R11: fffffbfff1f3efdf R12: 1ffff110170e823d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b87411e8 FS: 00007f48f517a6c0(0000) GS:ffff888125c99000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ea1fffc CR3: 0000000045d80000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: csd_lock_wait kernel/smp.c:340 [inline] smp_call_function_many_cond+0xe80/0x11c0 kernel/smp.c:885 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline] smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2870 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_slow_inc_cpuslocked+0x80/0xf0 kernel/jump_label.c:168 static_key_slow_inc+0x1a/0x30 kernel/jump_label.c:191 kvm_create_vm virt/kvm/kvm_main.c:1212 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5402 [inline] kvm_dev_ioctl+0x16a8/0x18e0 virt/kvm/kvm_main.c:5444 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f48f438e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f48f517a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f48f45b5fa0 RCX: 00007f48f438e969 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003 RBP: 00007f48f4410ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f48f45b5fa0 R15: 00007ffdbcf54bb8 vkms_vblank_simulate: vblank timer overrun