rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=37cc/1/0x4000000000000000 softirq=50462/50463 fqs=4 rcu: (detected by 1, t=10502 jiffies, g=81977, q=169 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 21610 Comm: syz-executor.0 Not tainted 6.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 RIP: 0010:mark_lock+0x55/0xc50 kernel/locking/lockdep.c:4639 Code: 8a b5 41 48 8d 44 24 30 48 c7 44 24 38 30 1e 84 8c 48 c1 e8 03 48 c7 44 24 40 70 24 68 81 49 89 c7 48 01 d0 c7 00 f1 f1 f1 f1 40 04 00 f2 f2 f2 c7 40 08 00 f2 f2 f2 c7 40 10 00 00 00 f3 c7 RSP: 0018:ffffc900000079b0 EFLAGS: 00000086 RAX: fffff52000000f3c RBX: ffff88802a9046b2 RCX: 0000000000000002 RDX: dffffc0000000000 RSI: ffff88802a904690 RDI: ffff88802a903b80 RBP: ffffc90000007ae8 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff92157f4f R11: ffffffff8acf30a0 R12: ffff88802a904690 R13: ffffed10055208c7 R14: 0000000000000000 R15: 1ffff92000000f3c FS: 00007f05e4a956c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020fab030 CR3: 000000004130f000 CR4: 0000000000350ef0 Call Trace: mark_usage kernel/locking/lockdep.c:4564 [inline] __lock_acquire+0x137a/0x3b30 kernel/locking/lockdep.c:5091 lock_acquire kernel/locking/lockdep.c:5754 [inline] lock_acquire+0x1ae/0x520 kernel/locking/lockdep.c:5719 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x3a/0x50 kernel/locking/spinlock.c:162 debug_object_deactivate+0x138/0x370 lib/debugobjects.c:763 debug_hrtimer_deactivate kernel/time/hrtimer.c:427 [inline] debug_deactivate kernel/time/hrtimer.c:483 [inline] __run_hrtimer kernel/time/hrtimer.c:1656 [inline] __hrtimer_run_queues+0x470/0xc20 kernel/time/hrtimer.c:1752 hrtimer_interrupt+0x31b/0x800 kernel/time/hrtimer.c:1814 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1065 [inline] __sysvec_apic_timer_interrupt+0x105/0x400 arch/x86/kernel/apic/apic.c:1082 sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1076 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:649 RIP: 0010:save_stack+0x75/0x1f0 mm/page_owner.c:114 Code: f3 f3 f3 65 48 8b 04 25 28 00 00 00 48 89 84 24 d8 00 00 00 31 c0 e8 9a 2f 9f ff 31 c0 b9 10 00 00 00 4c 8d 64 24 20 4c 89 e7 48 ab 65 48 8b 2c 25 80 c2 03 00 48 8d bd 61 05 00 00 48 89 f8 RSP: 0018:ffffc90016246f38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff92002c48de7 RCX: 000000000000000f RDX: 0000000000040000 RSI: ffffffff81e8f706 RDI: ffffc90016246f60 RBP: 0000000000000000 R08: 0000160000000000 R09: 0000000000000000 R10: ffffed1006e02c00 R11: dffffc0000000000 R12: ffffc90016246f58 R13: 0000000000140dca R14: dffffc0000000000 R15: 0000000000000000 __set_page_owner+0x1f/0x60 mm/page_owner.c:195 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d0/0x350 mm/page_alloc.c:1533 prep_new_page mm/page_alloc.c:1540 [inline] get_page_from_freelist+0xa28/0x3780 mm/page_alloc.c:3311 __alloc_pages+0x22f/0x2440 mm/page_alloc.c:4567 alloc_pages_mpol+0x258/0x5f0 mm/mempolicy.c:2133 vma_alloc_folio+0xad/0x220 mm/mempolicy.c:2172 folio_prealloc mm/memory.c:1003 [inline] wp_page_copy mm/memory.c:3138 [inline] do_wp_page+0x1766/0x37b0 mm/memory.c:3525 handle_pte_fault mm/memory.c:5160 [inline] __handle_mm_fault+0x1f87/0x4900 mm/memory.c:5285 handle_mm_fault+0x47a/0xa10 mm/memory.c:5450 do_user_addr_fault+0x3f8/0x1030 arch/x86/mm/fault.c:1415 handle_page_fault arch/x86/mm/fault.c:1507 [inline] exc_page_fault+0x5d/0xc0 arch/x86/mm/fault.c:1563 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570 RIP: 0010:__put_user_nocheck_4+0x7/0x10 arch/x86/lib/putuser.S:97 Code: 01 ca c3 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 d9 0f 01 cb 89 01 31 c9 0f 01 ca c3 0f 1f 80 00 00 00 00 f3 0f 1e fa 0f 01 cb <89> 01 31 c9 0f 01 ca c3 90 f3 0f 1e fa 48 89 cb 48 c1 fb 3f 48 09 RSP: 0018:ffffc900162479d8 EFLAGS: 00050246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000020fab030 RDX: 0000000000040000 RSI: ffffffff8870a5ca RDI: 0000000000000005 RBP: ffffc90016247d98 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000020fab000 R14: ffffc90016247ddc R15: 0000000000000002 ____sys_recvmsg+0x2f5/0x5c0 net/socket.c:2816 ___sys_recvmsg+0x115/0x1a0 net/socket.c:2845 do_recvmmsg+0x2af/0x740 net/socket.c:2939 __sys_recvmmsg net/socket.c:3018 [inline] __do_sys_recvmmsg net/socket.c:3041 [inline] __se_sys_recvmmsg net/socket.c:3034 [inline] __x64_sys_recvmmsg+0x235/0x290 net/socket.c:3034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xd3/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f05e3c7cda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f05e4a950c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00007f05e3dac050 RCX: 00007f05e3c7cda9 RDX: 00000000040002db RSI: 0000000020000740 RDI: 0000000000000004 RBP: 00007f05e3cc947a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f05e3dac050 R15: 00007ffd093c1a28 rcu: rcu_preempt kthread starved for 10494 jiffies! g81977 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:27984 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5400 [inline] __schedule+0xf12/0x5c00 kernel/sched/core.c:6727 __schedule_loop kernel/sched/core.c:6802 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6817 schedule_timeout+0x137/0x290 kernel/time/timer.c:2183 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1862 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 2926 Comm: kworker/u4:11 Not tainted 6.8.0-rc2-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4e9/0x1550 kernel/smp.c:855 Code: 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 7e c5 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 24 0e 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc9000a277930 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b9844940 RCX: ffffffff817c6148 RDX: ffff88802a3bd940 RSI: ffffffff817c6122 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed1017308929 R13: 0000000000000001 R14: ffff8880b9844948 R15: ffff8880b993de80 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f410f578198 CR3: 000000000cf78000 CR4: 0000000000350ef0 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:2087 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2297 text_poke_flush arch/x86/kernel/alternative.c:2488 [inline] text_poke_flush arch/x86/kernel/alternative.c:2485 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2495 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:826 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:818 process_one_work+0x886/0x15d0 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2787 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242