rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16549/1:b..l rcu: (detected by 0, t=10502 jiffies, g=159021, q=173 ncpus=2) task:syz.1.4941 state:R running task stack:25776 pid:16549 tgid:16548 ppid:5266 flags:0x00004006 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:__page_table_check_zero+0x195/0x370 mm/page_table_check.c:156 Code: df e8 ff be f5 ff 48 89 d8 48 c1 e8 03 42 0f b6 14 38 48 89 d8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 99 01 00 00 44 8b 33 <31> ff 44 89 f6 e8 f1 8d 98 ff 45 85 f6 0f 85 50 01 00 00 e8 a3 8b RSP: 0018:ffffc9000323ef68 EFLAGS: 00000246 RAX: 0000000000000003 RBX: ffff888018533488 RCX: ffffffff81f1ec41 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888018533488 RBP: ffff888018533440 R08: 0000000000000000 R09: ffffed10030a6691 R10: ffff88801853348b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 page_table_check_alloc include/linux/page_table_check.h:33 [inline] post_alloc_hook+0x2c0/0x350 mm/page_alloc.c:1494 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3442 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4700 alloc_pages_mpol_noprof+0x275/0x610 mm/mempolicy.c:2263 folio_alloc_mpol_noprof+0x36/0xd0 mm/mempolicy.c:2281 vma_alloc_folio_noprof+0xee/0x1b0 mm/mempolicy.c:2312 folio_prealloc mm/memory.c:1060 [inline] wp_page_copy mm/memory.c:3335 [inline] do_wp_page+0xfd7/0x3430 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:ffffc9000323f958 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000001000 RCX: 0000000000000e80 RDX: 0000000000000000 RSI: ffff888013233180 RDI: 00000000206c3000 RBP: 0000000000001000 R08: 0000000000000000 R09: ffffed10026467ff R10: ffff888013233fff R11: 0000000000000000 R12: 00000000006c2b80 R13: ffffc9000323fd50 R14: ffff888013233000 R15: 00000000206c2e80 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+0x5c9/0x9f0 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: 0033:0x7fef70979e79 RSP: 002b:00007fef71699038 EFLAGS: 00000246 ORIG_RAX: 0000000000000136 RAX: ffffffffffffffda RBX: 00007fef70b15f80 RCX: 00007fef70979e79 RDX: 0000000000000002 RSI: 0000000020008400 RDI: 000000000000089f RBP: 00007fef709e7916 R08: 0000000000000286 R09: 0000000000000000 R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fef70b15f80 R15: 00007ffd71e78e58 rcu: rcu_preempt kthread starved for 10492 jiffies! g159021 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:27584 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: 0 UID: 0 PID: 2580 Comm: kworker/u8:11 Not tainted 6.11.0-rc3-syzkaller-00279-ge5fa841af679 #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+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 0b 33 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:ffffc900090e7908 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9344b80 RCX: ffffffff817e453b RDX: ffff88802a823c00 RSI: ffffffff817e4515 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: ffffed1017268971 R13: 0000000000000001 R14: ffff8880b9344b88 R15: ffff8880b923ffc0 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f38d8e1d723 CR3: 000000000db7c000 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 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2085 [inline] text_poke_bp_batch+0x22b/0x760 arch/x86/kernel/alternative.c:2295 text_poke_flush arch/x86/kernel/alternative.c:2486 [inline] text_poke_flush arch/x86/kernel/alternative.c:2483 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2493 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:900 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate mm/kfence/core.c:833 [inline] toggle_allocation_gate+0xf8/0x250 mm/kfence/core.c:825 process_one_work+0x9c5/0x1b40 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf20 kernel/workqueue.c:3390 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