rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10499 ticks this GP) idle=f87/1/0x4000000000000000 softirq=45478/45478 fqs=13 (t=10500 jiffies g=75809 q=157) rcu: rcu_preempt kthread starved for 10472 jiffies! g75809 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:28208 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4965 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6246 schedule+0xd2/0x260 kernel/sched/core.c:6319 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1966 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2139 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 17904 Comm: kworker/1:15 Not tainted 5.15.0-rc5-next-20211015-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events prog_array_map_clear_deferred RIP: 0010:__lock_acquire+0xb58/0x54a0 kernel/locking/lockdep.c:5022 Code: b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 c7 c0 a8 06 90 8d 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 90 45 00 00 <8b> 05 9a d6 33 0c 85 c0 0f 85 a3 00 00 00 8b 44 24 18 85 c0 0f 85 RSP: 0000:ffffc9000493f8b0 EFLAGS: 00000046 RAX: 0000000000000003 RBX: 000000001468e735 RCX: ffffffff815c34ca RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888088a7c4d9 RBP: ffff888088a7c4da R08: 0000000000000000 R09: ffffffff8ff44b77 R10: fffffbfff1fe896e R11: 0000000000000000 R12: ffff888088a7c4b8 R13: ffff888088a7ba00 R14: 0000000000000000 R15: 51468e7399dc752c FS: 0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000c8e818 CR3: 000000007f49b000 CR4: 00000000003526e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 __mutex_lock_common kernel/locking/mutex.c:599 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:732 fd_array_map_delete_elem+0x120/0x2e0 kernel/bpf/arraymap.c:821 bpf_fd_array_map_clear kernel/bpf/arraymap.c:871 [inline] prog_array_map_clear_deferred+0x10b/0x1b0 kernel/bpf/arraymap.c:1050 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 NMI backtrace for cpu 0 CPU: 0 PID: 9393 Comm: kworker/0:16 Not tainted 5.15.0-rc5-next-20211015-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events prog_array_map_clear_deferred Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3889 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2608 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: ec a5 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 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: 0000:ffffc90001b7f9f0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200036ff40 RCX: ffffffff815c3adf RDX: 1ffff11002fdc4ec RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ff44b77 R10: fffffbfff1fe896e R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880a06de488 R15: 0000000000000000 __mutex_lock_common kernel/locking/mutex.c:599 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:732 fd_array_map_delete_elem+0x120/0x2e0 kernel/bpf/arraymap.c:821 bpf_fd_array_map_clear kernel/bpf/arraymap.c:871 [inline] prog_array_map_clear_deferred+0x10b/0x1b0 kernel/bpf/arraymap.c:1050 process_one_work+0x9b2/0x1690 kernel/workqueue.c:2297 worker_thread+0x658/0x11f0 kernel/workqueue.c:2444 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 ---------------- Code disassembly (best guess): 0: b8 00 00 00 00 mov $0x0,%eax 5: 00 fc add %bh,%ah 7: ff (bad) 8: df 48 c1 fisttps -0x3f(%rax) b: ea (bad) c: 03 0f add (%rdi),%ecx e: b6 14 mov $0x14,%dh 10: 02 48 c7 add -0x39(%rax),%cl 13: c0 a8 06 90 8d 83 e0 shrb $0xe0,-0x7c726ffa(%rax) 1a: 07 (bad) 1b: 83 c0 03 add $0x3,%eax 1e: 38 d0 cmp %dl,%al 20: 7c 08 jl 0x2a 22: 84 d2 test %dl,%dl 24: 0f 85 90 45 00 00 jne 0x45ba * 2a: 8b 05 9a d6 33 0c mov 0xc33d69a(%rip),%eax # 0xc33d6ca <-- trapping instruction 30: 85 c0 test %eax,%eax 32: 0f 85 a3 00 00 00 jne 0xdb 38: 8b 44 24 18 mov 0x18(%rsp),%eax 3c: 85 c0 test %eax,%eax 3e: 0f .byte 0xf 3f: 85 .byte 0x85