rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=38d/1/0x4000000000000000 softirq=10159/10160 fqs=234 (t=10500 jiffies g=11181 q=11) rcu: rcu_preempt kthread starved for 9849 jiffies! g11181 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:29304 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 2713 Comm: kworker/0:3 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:check_preemption_disabled+0x2/0x170 lib/smp_processor_id.c:13 Code: 1f 44 00 00 e8 6f 16 4e f8 65 48 8b 3c 25 40 70 02 00 e8 41 43 05 f8 eb 99 0f 1f 44 00 00 0f 0b e9 23 ff ff ff cc cc cc 41 56 <41> 55 49 89 f5 41 54 55 48 89 fd 53 0f 1f 44 00 00 65 44 8b 25 cd RSP: 0018:ffffc9000b95fa68 EFLAGS: 00000046 RAX: 0000000000000002 RBX: c8757c4f6cfa24cc RCX: ffffc9000b95fac8 RDX: 1ffff110046b014b RSI: ffffffff89ac08c0 RDI: ffffffff8a046f60 RBP: 1ffff9200172bf51 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000003 R14: ffff888023580a60 R15: ffff888023580000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555567352c0 CR3: 000000000b88e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:438 [inline] lock_release+0x3bb/0x720 kernel/locking/lockdep.c:5659 __mutex_unlock_slowpath+0x99/0x5e0 kernel/locking/mutex.c:892 fd_array_map_delete_elem+0x1b0/0x2e0 kernel/bpf/arraymap.c:824 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 1 CPU: 1 PID: 23 Comm: kworker/1:1 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_is_held_type+0xff/0x140 kernel/locking/lockdep.c:5685 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 0c 1a b5 76 83 f8 01 75 29 9c 58 f6 c4 02 75 3d 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 45 31 ed eb b9 0f 0b 48 RSP: 0018:ffffc90000ddfa30 EFLAGS: 00000296 RAX: 0000000000000046 RBX: 0000000000000003 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8bb82de0 R08: 0000000000000000 R09: ffffffff8d8fd297 R10: fffffbfff1b1fa52 R11: 0000000000000000 R12: ffff8880157b0000 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff8880157b0ab8 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_release include/trace/events/lock.h:58 [inline] lock_release+0x522/0x720 kernel/locking/lockdep.c:5648 __mutex_unlock_slowpath+0x99/0x5e0 kernel/locking/mutex.c:892 fd_array_map_delete_elem+0x1b0/0x2e0 kernel/bpf/arraymap.c:824 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), 1 bytes skipped: 0: 44 00 00 add %r8b,(%rax) 3: e8 6f 16 4e f8 callq 0xf84e1677 8: 65 48 8b 3c 25 40 70 mov %gs:0x27040,%rdi f: 02 00 11: e8 41 43 05 f8 callq 0xf8054357 16: eb 99 jmp 0xffffffb1 18: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 1d: 0f 0b ud2 1f: e9 23 ff ff ff jmpq 0xffffff47 24: cc int3 25: cc int3 26: cc int3 27: 41 56 push %r14 * 29: 41 55 push %r13 <-- trapping instruction 2b: 49 89 f5 mov %rsi,%r13 2e: 41 54 push %r12 30: 55 push %rbp 31: 48 89 fd mov %rdi,%rbp 34: 53 push %rbx 35: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 3a: 65 gs 3b: 44 rex.R 3c: 8b .byte 0x8b 3d: 25 .byte 0x25 3e: cd .byte 0xcd