rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10508 ticks this GP) idle=88f/1/0x4000000000000000 softirq=68312/68314 fqs=3 (t=10500 jiffies g=115161 q=2) rcu: rcu_preempt kthread starved for 10491 jiffies! g115161 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:28696 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4969 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6250 schedule+0xd2/0x260 kernel/sched/core.c:6323 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 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: 5 Comm: kworker/0:0 Not tainted 5.15.0-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:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_preemption_disabled+0x1b/0x170 lib/smp_processor_id.c:16 Code: 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 3d 87 ca 76 <65> 8b 1d ae e1 ca 76 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 RSP: 0018:ffffc90000ca7970 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff898c0920 RDI: ffffffff89e46e40 RBP: ffffffff89e46e40 R08: 0000000000000000 R09: ffffffff8d6f5757 R10: fffffbfff1adeaea R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff898c0920 R14: 00000000ffffffff R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f6057c489e0 CR3: 000000000b68e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:433 [inline] lock_is_held_type+0x63/0x140 kernel/locking/lockdep.c:5667 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5596 __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 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 1 CPU: 1 PID: 16723 Comm: kworker/1:11 Not tainted 5.15.0-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:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 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:1421 __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:5673 Code: 00 00 b8 ff ff ff ff 65 0f c1 05 5c f8 ca 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:ffffc900043079a8 EFLAGS: 00000282 RAX: 0000000000000046 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffffff8b982ce0 R08: 0000000000000000 R09: ffffffff8d6f5757 R10: fffffbfff1adeaea R11: 0000000000000000 R12: ffff888025541d00 R13: 0000000000000000 R14: 00000000ffffffff R15: ffff888025542788 lock_is_held include/linux/lockdep.h:283 [inline] rcu_read_lock_sched_held+0x3a/0x70 kernel/rcu/update.c:125 trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x442/0x510 kernel/locking/lockdep.c:5596 __mutex_lock_common kernel/locking/mutex.c:607 [inline] __mutex_lock+0x12f/0x12f0 kernel/locking/mutex.c:740 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: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 5: 0f 0b ud2 7: e9 23 ff ff ff jmpq 0xffffff2f c: cc int3 d: cc int3 e: cc int3 f: 41 56 push %r14 11: 41 55 push %r13 13: 49 89 f5 mov %rsi,%r13 16: 41 54 push %r12 18: 55 push %rbp 19: 48 89 fd mov %rdi,%rbp 1c: 53 push %rbx 1d: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1) 22: 65 44 8b 25 3d 87 ca mov %gs:0x76ca873d(%rip),%r12d # 0x76ca8767 29: 76 * 2a: 65 8b 1d ae e1 ca 76 mov %gs:0x76cae1ae(%rip),%ebx # 0x76cae1df <-- trapping instruction 31: 81 e3 ff ff ff 7f and $0x7fffffff,%ebx 37: 31 ff xor %edi,%edi 39: 89 de mov %ebx,%esi 3b: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)