rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=4e14/1/0x4000000000000000 softirq=83616/83616 fqs=0
rcu: 	(detected by 0, t=10506 jiffies, g=68981, q=109 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 17745 Comm: syz.4.2940 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:do_raw_spin_lock+0x155/0x290
Code: 0f b1 0b 0f 85 dd 00 00 00 65 8b 1d 69 bb 02 11 48 b9 00 00 00 00 00 fc ff df 41 0f b6 04 0f 49 89 cf 84 c0 0f 85 0b 01 00 00 <41> 89 5d 00 43 80 3c 3e 00 74 08 4c 89 e7 e8 e8 2a 85 00 48 8b 44
RSP: 0018:ffffc900001e07c0 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000001 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc900001e0800
RBP: ffffc900001e0870 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200003c100 R12: ffff888136627a90
R13: ffff888136627a88 R14: 1ffff11026cc4f52 R15: dffffc0000000000
FS:  00007f905e95c6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003ff6 CR3: 00000001307c4000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 _raw_spin_lock_irqsave+0xb3/0xf0
 hrtimer_try_to_cancel+0x22b/0x420
 hrtimer_cancel+0x3b/0x50
 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:rcu_is_watching+0x15/0xb0
Code: 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 53 65 ff 05 30 5e fa 10 e8 1b ff d3 09 <89> c3 83 f8 08 73 65 49 bf 00 00 00 00 00 fc ff df 4c 8d 34 dd 10
RSP: 0018:ffffc90007c46f98 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffffff8b7a001a RCX: b6ffdd8182a9dd00
RDX: 0000000000000001 RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff8172d195
R10: ffffc90007c470d8 R11: ffffffff81ac4d00 R12: 1ffff92000f88e11
R13: ffffc90007c470c0 R14: ffffc90007c47088 R15: ffffffff8172d195
 unwind_next_frame+0xd4/0x2390
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 compute_live_registers+0x1920/0x1a50
 bpf_check+0x17418/0x1d2c0
 bpf_prog_load+0x1318/0x1930
 __sys_bpf+0x528/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f905db8eba9
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:00007f905e95c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f905ddd5fa0 RCX: 00007f905db8eba9
RDX: 0000000000000048 RSI: 000020000000e000 RDI: 0000000000000005
RBP: 00007f905dc11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f905ddd6038 R14: 00007f905ddd5fa0 R15: 00007fffec20a778
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g68981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=31893
rcu: rcu_preempt kthread starved for 10506 jiffies! g68981 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26664 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>
