rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9755/1:b..l P9758/1:b..l rcu: (detected by 1, t=10502 jiffies, g=45549, q=663 ncpus=2) task:syz.0.1582 state:R running task stack:27552 pid:9758 tgid:9754 ppid:5236 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 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 3a 13 9a 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:ffffc9000335f818 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200066bf05 RCX: 0000000000000001 RDX: 0000000000000001 RSI: ffffffff8b4cc880 RDI: ffffffff8bb08c00 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff28c4cd8 R10: ffffffff946266c7 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8ddb5220 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:326 [inline] rcu_read_lock include/linux/rcupdate.h:838 [inline] __pte_offset_map+0x48/0x540 mm/pgtable-generic.c:287 __pte_offset_map_lock+0x8e/0x300 mm/pgtable-generic.c:371 pte_offset_map_lock include/linux/mm.h:2985 [inline] follow_page_pte+0xde/0x1cf0 mm/gup.c:832 follow_pmd_mask mm/gup.c:974 [inline] follow_pud_mask mm/gup.c:1006 [inline] follow_p4d_mask mm/gup.c:1023 [inline] follow_page_mask+0x3a1/0x21d0 mm/gup.c:1066 __get_user_pages+0x32d/0x15c0 mm/gup.c:1491 populate_vma_page_range+0x27f/0x3a0 mm/gup.c:1932 __mm_populate+0x1d6/0x380 mm/gup.c:2035 mm_populate include/linux/mm.h:3429 [inline] vm_mmap_pgoff+0x293/0x360 mm/util.c:593 ksys_mmap_pgoff+0x332/0x5d0 mm/mmap.c:1514 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:79 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:79 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: 0033:0x7fe4569772d3 RSP: 002b:00007fe4576dbfd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fe456b06058 RCX: 00007fe4569772d3 RDX: 0000000000000003 RSI: 0000000000100000 RDI: 0000000000000000 RBP: 0000000020000080 R08: 0000000000000008 R09: 0000000010000000 R10: 0000000000008001 R11: 0000000000000246 R12: 0000000000000008 R13: 0000000020000100 R14: 00000000000024f5 R15: 0000000020000000 task:syz.0.1582 state:R running task stack:25888 pid:9755 tgid:9754 ppid:5236 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5188 [inline] __schedule+0xe37/0x5490 kernel/sched/core.c:6529 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6708 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3436 [inline] do_wp_page+0x15fd/0x3430 mm/memory.c:3727 handle_pte_fault mm/memory.c:5538 [inline] __handle_mm_fault+0x2468/0x5660 mm/memory.c:5665 handle_mm_fault+0x44e/0x7b0 mm/memory.c:5833 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:rep_movs_alternative+0x4a/0x70 arch/x86/lib/copy_user_64.S:71 Code: 75 f1 c3 cc cc cc cc 66 0f 1f 84 00 00 00 00 00 48 8b 06 48 89 07 48 83 c6 08 48 83 c7 08 83 e9 08 74 df 83 f9 08 73 e8 eb c9 a4 c3 cc cc cc cc 48 89 c8 48 c1 e9 03 83 e0 07 f3 48 a5 89 c1 RSP: 0018:ffffc9000330f958 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000000000 RSI: ffff88801322f180 RDI: 000000002018f000 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffed1002645fff R10: ffff88801322ffff R11: 0000000000000000 R12: 000000000018eb80 R13: ffffc9000330fd50 R14: ffff88801322f000 R15: 000000002018ee80 copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:131 [inline] copy_to_user_iter lib/iov_iter.c:25 [inline] iterate_iovec include/linux/iov_iter.h:51 [inline] iterate_and_advance2 include/linux/iov_iter.h:247 [inline] iterate_and_advance include/linux/iov_iter.h:271 [inline] _copy_to_iter+0x4d2/0x1150 lib/iov_iter.c:185 copy_page_to_iter lib/iov_iter.c:362 [inline] copy_page_to_iter+0xf1/0x180 lib/iov_iter.c:349 process_vm_rw_pages mm/process_vm_access.c:45 [inline] process_vm_rw_single_vec mm/process_vm_access.c:118 [inline] process_vm_rw_core.constprop.0+0x5c9/0xa10 mm/process_vm_access.c:216 process_vm_rw+0x301/0x360 mm/process_vm_access.c:284 __do_sys_process_vm_readv mm/process_vm_access.c:296 [inline] __se_sys_process_vm_readv mm/process_vm_access.c:292 [inline] __x64_sys_process_vm_readv+0xe2/0x1c0 mm/process_vm_access.c:292 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: 0033:0x7fe456977299 RSP: 002b:00007fe4576fd048 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007fe456b05f80 RCX: 00007fe456977299 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000377 RBP: 00007fe4569e48e6 R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fe456b05f80 R15: 00007ffff76fd178 rcu: rcu_preempt kthread starved for 10573 jiffies! g45549 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: 0 Comm: swapper/1 Not tainted 6.10.0-syzkaller-12708-g2f8c4f506285 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline] RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 48 69 f2 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d b8 82 aa 00 fb f4 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900001a7d58 EFLAGS: 00000246 RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b115519 RDX: 0000000000000001 RSI: ffff88801aa8b000 RDI: ffff88801aa8b064 RBP: ffff88801aa8b064 R08: 0000000000000001 R09: ffffed1017266fe1 R10: ffff8880b9337f0b R11: 0000000000000000 R12: ffff88801c73a800 R13: ffffffff8e94fdc0 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b317faff8 CR3: 000000006aee6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:702 cpuidle_enter_state+0x85/0x500 drivers/cpuidle/cpuidle.c:267 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:388 cpuidle_idle_call kernel/sched/idle.c:230 [inline] do_idle+0x313/0x3f0 kernel/sched/idle.c:326 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148