rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=12a4/1/0x4000000000000000 softirq=20916/20917 fqs=0 rcu: (detected by 1, t=10505 jiffies, g=34893, q=100 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8927 Comm: syz.1.1603 Not tainted 6.11.0-rc7-syzkaller-00020-g8d8d276ba2fb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:hlock_id kernel/locking/lockdep.c:429 [inline] RIP: 0010:__lock_acquire+0xac7/0x3cb0 kernel/locking/lockdep.c:5130 Code: 04 02 84 c0 74 08 3c 03 0f 8e 2b 2c 00 00 41 0f b7 45 20 66 25 ff 1f 66 89 44 24 20 41 0f b6 45 22 83 e0 03 48 83 7c 24 10 00 <88> 44 24 38 0f 84 b8 00 00 00 65 4c 8b 25 97 51 9a 7e 4d 8d 84 24 RSP: 0018:ffffc90000007be0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: ca5833516188a989 RCX: ffffffff81698ce8 RDX: 1ffff1100511f8f4 RSI: 0000000000000008 RDI: ffff8880288fc7a1 RBP: 0000000000000040 R08: 0000000000000000 R09: fffffbfff2d248e1 R10: ffffffff9692470f R11: 0000000000000000 R12: ffff8880288fc779 R13: ffff8880288fc780 R14: 0000000000000002 R15: ffff8880288fbc00 FS: 0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32b16ff8 CR3: 0000000031ac6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5759 [inline] lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] _raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170 __run_hrtimer kernel/time/hrtimer.c:1693 [inline] __hrtimer_run_queues+0x2c0/0xcc0 kernel/time/hrtimer.c:1753 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1815 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x10f/0x450 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 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+0x1f2/0x560 kernel/locking/lockdep.c:5727 Code: c1 05 1a ba 98 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000301f728 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff92000603ee7 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cda40 RDI: ffffffff8bb0fc00 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2d248e0 R10: ffffffff96924707 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb9f20 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock_sched include/linux/rcupdate.h:930 [inline] pfn_valid include/linux/mmzone.h:2022 [inline] page_table_check_clear mm/page_table_check.c:70 [inline] __page_table_check_pte_clear+0x1c0/0x580 mm/page_table_check.c:169 page_table_check_pte_clear include/linux/page_table_check.h:49 [inline] ptep_get_and_clear_full arch/x86/include/asm/pgtable.h:1284 [inline] 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+0x21ac/0x3c10 mm/memory.c:1807 unmap_single_vma+0x194/0x2b0 mm/memory.c:1853 unmap_vmas+0x22f/0x490 mm/memory.c:1897 exit_mmap+0x1b8/0xb20 mm/mmap.c:3412 __mmput+0x12a/0x480 kernel/fork.c:1345 mmput+0x62/0x70 kernel/fork.c:1367 exit_mm kernel/exit.c:571 [inline] do_exit+0x9bf/0x2bb0 kernel/exit.c:869 do_group_exit+0xd3/0x2a0 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+0x3e/0x50 kernel/exit.c:1040 x64_sys_call+0x14a9/0x16a0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d12f7def9 Code: Unable to access opcode bytes at 0x7f0d12f7decf. RSP: 002b:00007fff03be3168 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f0d12f7def9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fff03be31bc R08: 00007fff03be324f R09: 000000000004052b R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032 R13: 000000000004052b R14: 00000000000404c1 R15: 00007fff03be3210 rcu: rcu_preempt kthread starved for 10505 jiffies! g34893 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:27680 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 __schedule_loop kernel/sched/core.c:6606 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6621 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 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: 5239 Comm: syz-executor Not tainted 6.11.0-rc7-syzkaller-00020-g8d8d276ba2fb #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024 RIP: 0010:csd_lock_wait kernel/smp.c:312 [inline] RIP: 0010:smp_call_function_many_cond+0x4e7/0x1420 kernel/smp.c:856 Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 cb 34 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 f7 0c 00 00 8b 43 08 31 RSP: 0018:ffffc900037cf900 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8846940 RCX: ffffffff817f9bab RDX: ffff888065370000 RSI: ffffffff817f9b85 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1017108d29 R13: 0000000000000001 R14: ffff8880b8846948 R15: ffff8880b893ffc0 FS: 000055558e330500(0000) GS:ffff8880b8900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc7c2c656c0 CR3: 0000000031ac6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:941 [inline] flush_tlb_mm_range+0x293/0x330 arch/x86/mm/tlb.c:1027 dup_mmap kernel/fork.c:775 [inline] dup_mm kernel/fork.c:1672 [inline] copy_mm kernel/fork.c:1721 [inline] copy_process+0x7610/0x8de0 kernel/fork.c:2374 kernel_clone+0xfd/0x960 kernel/fork.c:2781 __do_sys_clone+0xba/0x100 kernel/fork.c:2924 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fc7c1f74753 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 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 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd84e19168 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fc7c1f74753 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 000055558e3307d0 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000004059d R14: 000000000004059d R15: 00007ffd84e192f0