rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14564/1:b..l rcu: (detected by 1, t=10502 jiffies, g=111705, q=483 ncpus=2) task:syz.4.1680 state:R running task stack:25920 pid:14564 tgid:14563 ppid:13704 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7067 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:debug_lockdep_rcu_enabled+0x28/0x40 kernel/rcu/update.c:320 Code: 90 90 f3 0f 1e fa 8b 05 b2 ad fc 04 85 c0 74 20 8b 05 94 df fc 04 85 c0 74 16 65 48 8b 05 f0 fe 1b 75 8b 80 dc 0a 00 00 85 c0 <0f> 94 c0 0f b6 c0 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 0f RSP: 0018:ffffc900032e7560 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000020367000 RCX: 00000000f014e05e RDX: 0000000000000001 RSI: ffffffff8b2cb200 RDI: ffffffff8b9039c0 RBP: 0000000020367000 R08: 0000000000000000 R09: fffffbfff284d858 R10: ffffffff9426c2c7 R11: 0000000000000001 R12: ffffc900032e75d0 R13: ffff888062865808 R14: ffffc900032e7748 R15: ffff88806961a9b0 rcu_read_lock include/linux/rcupdate.h:782 [inline] __pte_offset_map+0x4d/0x540 mm/pgtable-generic.c:287 pte_offset_map_nolock+0x84/0x1c0 mm/pgtable-generic.c:314 handle_pte_fault mm/memory.c:5367 [inline] __handle_mm_fault+0xbbe/0x5410 mm/memory.c:5524 handle_mm_fault+0x476/0xa00 mm/memory.c:5689 do_user_addr_fault+0x2e5/0xe50 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:ffffc900032e7958 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000000000 RSI: ffff888012e75180 RDI: 0000000020367000 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffed10025cebff R10: ffff888012e75fff R11: 0000000000000000 R12: 0000000000366b80 R13: ffffc900032e7d50 R14: ffff888012e75000 R15: 0000000020366e80 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+0x4d2/0x1140 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: 0033:0x7fc3fe375bd9 RSP: 002b:00007fc3ff0a7048 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007fc3fe503f60 RCX: 00007fc3fe375bd9 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 0000000000000033 RBP: 00007fc3fe3e4e60 R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc3fe503f60 R15: 00007ffe85f17c68 rcu: rcu_preempt kthread starved for 10510 jiffies! g111705 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:5408 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6745 __schedule_loop kernel/sched/core.c:6822 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6837 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2000 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2202 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 PID: 0 Comm: swapper/1 Not tainted 6.10.0-rc7-syzkaller-00254-g528dd46d0fc3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 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:72 [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 c8 d4 1b 75 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 78 72 b3 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: ffffffff8ae7e759 RDX: 0000000000000001 RSI: ffff888019a83800 RDI: ffff888019a83864 RBP: ffff888019a83864 R08: 0000000000000001 R09: ffffed1017266fdd R10: ffff8880b9337eeb R11: 0000000000000000 R12: ffff88801bb61000 R13: ffffffff8e745940 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 000000002c0fe000 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:236 [inline] do_idle+0x313/0x3f0 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 start_secondary+0x220/0x2b0 arch/x86/kernel/smpboot.c:313 common_startup_64+0x13e/0x148