rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (0 ticks this GP) idle=a87c/1/0x4000000000000000 softirq=16480/16480 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=9321, q=473 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6459 Comm: syz.0.153 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:hrtimer_cancel+0x33/0x50
Code: e8 a2 15 12 00 48 89 df e8 9a f9 ff ff 89 c5 31 ff 89 c6 e8 cf 19 12 00 85 ed 78 0c e8 86 15 12 00 eb 1a e8 7f 15 12 00 f3 90 <48> 89 df e8 75 f9 ff ff 85 c0 78 ed 89 c5 e8 6a 15 12 00 89 e8 5b
RSP: 0018:ffffc90000007990 EFLAGS: 00000006
RAX: ffffffff81adabe1 RBX: ffff88803c059a68 RCX: ffff8881114d3980
RDX: 0000000000010000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 00000000ffffffff R08: ffff88804b027a83 R09: 1ffff11009604f50
R10: dffffc0000000000 R11: ffffed1009604f51 R12: ffff88803c059b10
R13: dffffc0000000000 R14: ffff88803c059a68 R15: ffffffffffff36e5
FS:  00007fa50d44c6c0(0000) GS:ffff8880b8613000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555559b51808 CR3: 000000003b238000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 cpu_clock_event_stop+0xd9/0x130
 __perf_event_overflow+0x580/0xe40
 perf_swevent_hrtimer+0x3c5/0x550
 __hrtimer_run_queues+0x4e0/0xc60
 hrtimer_interrupt+0x45b/0xaa0
 __sysvec_apic_timer_interrupt+0x10b/0x410
 sysvec_apic_timer_interrupt+0xa1/0xc0
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:bpf_ksym_add+0x22e/0x340
Code: 0c 4c 8b 25 dc 6a 12 0c 4d 85 e4 0f 84 92 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 45 99 54 00 4c 8b 33 <49> 8d bc 24 c8 fd ff ff 48 89 f8 48 c1 e8 03 42 80 3c 28 00 74 05
RSP: 0018:ffffc9000644fb20 EFLAGS: 00000246
RAX: 1ffff110078b0241 RBX: ffff88803c581208 RCX: 1ffffffff1ea7b47
RDX: 0000000000000000 RSI: ffffffff8de113f0 RDI: ffff88803c581428
RBP: ffffffff8f53da38 R08: ffff88803c58143f R09: 0000000000000000
R10: ffff88803c581430 R11: ffffed10078b0288 R12: ffff88803c26c440
R13: dffffc0000000000 R14: ffffffffa0003898 R15: ffffffff8f53da48
 bpf_prog_load+0x1435/0x1930
 __sys_bpf+0x528/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa50c58eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa50d44c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fa50c7d5fa0 RCX: 00007fa50c58eba9
RDX: 0000000000000094 RSI: 0000200000000b40 RDI: 0000000000000005
RBP: 00007fa50c611e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa50c7d6038 R14: 00007fa50c7d5fa0 R15: 00007ffd9927aed8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g9321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=4730
rcu: rcu_preempt kthread starved for 10502 jiffies! g9321 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27224 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 schedule+0x165/0x360
 schedule_timeout+0x12b/0x270
 rcu_gp_fqs_loop+0x301/0x1540
 rcu_gp_kthread+0x99/0x390
 kthread+0x711/0x8a0
 ret_from_fork+0x439/0x7d0
 ret_from_fork_asm+0x1a/0x30
 </TASK>
