rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=9e4c/1/0x4000000000000000 softirq=51891/51893 fqs=0 rcu: (detected by 1, t=10502 jiffies, g=85457, q=253 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 18351 Comm: syz.0.5824 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:lock_is_held_type+0xf0/0x190 Code: 51 60 8e 48 89 ee e8 af 0b 34 f9 eb cb 31 db eb 1e 41 83 fe ff 74 13 31 c0 f6 43 22 03 0f 95 c0 31 db 44 39 f0 0f 94 c3 eb 05 01 00 00 00 48 c7 c7 e0 e6 ea 8b e8 cf 1a 00 00 b8 ff ff ff ff RSP: 0018:ffffc90000007d18 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff888028abe580 RCX: ffff888028abda00 RDX: ffff888028abda00 RSI: ffff8880b922c898 RDI: ffff888028abe580 RBP: 0000000000000004 R08: ffffffff8180d12e R09: 0000000000000000 R10: ffff8880200e2340 R11: ffffed100401c46b R12: 0000000000000046 R13: ffff888028abda00 R14: 00000000ffffffff R15: ffff8880b922c898 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3141eff8 CR3: 000000005f9ea000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:249 [inline] __run_hrtimer kernel/time/hrtimer.c:1655 [inline] __hrtimer_run_queues+0x2d9/0xd50 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x110/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x264/0x550 kernel/locking/lockdep.c:5763 Code: 2b 00 74 08 4c 89 f7 e8 fa d6 87 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900127573c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920024eae84 RCX: 20dde4fc1b9caf00 RDX: dffffc0000000000 RSI: ffffffff8beae6e0 RDI: ffffffff8c3f9980 RBP: ffffc90012757510 R08: ffffffff934f4847 R09: 1ffffffff269e908 R10: dffffc0000000000 R11: fffffbfff269e909 R12: 1ffff920024eae80 R13: dffffc0000000000 R14: ffffc90012757420 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock_sched include/linux/rcupdate.h:930 [inline] pfn_valid+0x113/0x450 include/linux/mmzone.h:2022 page_table_check_clear+0x1e/0x550 mm/page_table_check.c:70 get_and_clear_full_ptes include/linux/pgtable.h:678 [inline] zap_present_folio_ptes mm/memory.c:1493 [inline] zap_present_ptes mm/memory.c:1576 [inline] zap_pte_range mm/memory.c:1618 [inline] zap_pmd_range mm/memory.c:1736 [inline] zap_pud_range mm/memory.c:1765 [inline] zap_p4d_range mm/memory.c:1786 [inline] unmap_page_range+0x2b48/0x42c0 mm/memory.c:1807 unmap_vmas+0x3cc/0x5f0 mm/memory.c:1897 exit_mmap+0x264/0xc80 mm/mmap.c:3412 __mmput+0x115/0x380 kernel/fork.c:1345 exit_mm+0x220/0x310 kernel/exit.c:571 do_exit+0x9b2/0x27f0 kernel/exit.c:869 do_group_exit+0x207/0x2c0 kernel/exit.c:1031 __do_sys_exit_group kernel/exit.c:1042 [inline] __se_sys_exit_group kernel/exit.c:1040 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1040 x64_sys_call+0x2634/0x2640 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7595179e79 Code: Unable to access opcode bytes at 0x7f7595179e4f. RSP: 002b:00007fff2b28f638 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7595179e79 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff2b28f68c R08: 00007fff2b28f71f R09: 0000000000083523 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000083523 R14: 00000000000831ce R15: 00007fff2b28f6e0 rcu: rcu_preempt kthread starved for 10502 jiffies! g85457 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:25096 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0x17ae/0x4a10 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6621 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 185 Comm: kworker/u8:5 Not tainted 6.11.0-rc4-syzkaller-00033-g872cf28b8df9 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:312 [inline] RIP: 0010:smp_call_function_many_cond+0x1860/0x29d0 kernel/smp.c:856 Code: 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 19 15 0c 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c4 10 0c 00 eb 38 f3 90 <42> 0f b6 04 23 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 a8 10 RSP: 0018:ffffc90002e5f700 EFLAGS: 00000293 RAX: ffffffff81877a08 RBX: 1ffff11017248c59 RCX: ffff88801cf15a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90002e5f8e0 R08: ffffffff818779d7 R09: 1ffffffff269e908 R10: dffffc0000000000 R11: fffffbfff269e909 R12: dffffc0000000000 R13: ffff8880b92462c8 R14: ffff8880b933fb00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3271aff8 CR3: 000000000e534000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_disable_cpuslocked+0xd2/0x1c0 kernel/jump_label.c:240 static_key_disable+0x1a/0x20 kernel/jump_label.c:248 toggle_allocation_gate+0x1b8/0x250 mm/kfence/core.c:838 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 vkms_vblank_simulate: vblank timer overrun