rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P8706/1:b.el
rcu: 	(detected by 0, t=10502 jiffies, g=22609, q=214 ncpus=2)
task:syz.4.729       state:R  running task     stack:23224 pid:8706  tgid:8705  ppid:7228   task_flags:0x400140 flags:0x00004006
Call Trace:
 <TASK>
 __schedule+0x1798/0x4cc0
 preempt_schedule_common+0x83/0xd0
 preempt_schedule+0xae/0xc0
 preempt_schedule_thunk+0x16/0x30
 __local_bh_enable_ip+0x13e/0x1c0
 bpf_test_run+0x376/0x7b0
 bpf_prog_test_run_skb+0xc73/0x1700
 bpf_prog_test_run+0x2c7/0x340
 __sys_bpf+0x581/0x870
 __x64_sys_bpf+0x7c/0x90
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f84f2b8eba9
RSP: 002b:00007f84f3a18038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f84f2dd5fa0 RCX: 00007f84f2b8eba9
RDX: 0000000000000050 RSI: 00002000000003c0 RDI: 000000000000000a
RBP: 00007f84f2c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f84f2dd6038 R14: 00007f84f2dd5fa0 R15: 00007ffd94c614d8
 </TASK>
rcu: rcu_preempt kthread starved for 10435 jiffies! g22609 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:27160 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>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 8709 Comm: syz.5.730 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:check_preemption_disabled+0x49/0x120
Code: 8b 0d bb 5e 26 07 f7 c1 ff ff ff 7f 74 23 65 48 8b 0d 9b 5e 26 07 48 3b 4c 24 08 0f 85 cc 00 00 00 48 83 c4 10 5b 41 5e 41 5f <5d> e9 81 ca 02 00 cc 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24
RSP: 0018:ffffc900001e07b0 EFLAGS: 00000082
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 463dea331fada400
RDX: 0000000000000000 RSI: ffffffff8be33de0 RDI: ffffffff8be33da0
RBP: ffffffff81ada78b R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1026cc4f51 R12: 0000000000000000
R13: ffff888136627a98 R14: 0000000000000000 R15: 0000000000000001
FS:  00007faae2ada6c0(0000) GS:ffff8881a3c13000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000035c0 CR3: 000000010a09e000 CR4: 00000000000006f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_is_watching+0x15/0xb0
 lock_acquire+0x5f/0x360
 _raw_spin_lock_irqsave+0xa7/0xf0
 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:unwind_next_frame+0x12f6/0x2390
Code: 43 06 00 00 49 89 d5 48 89 d5 48 89 d8 48 29 e8 48 89 c1 48 c1 f9 02 48 c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 <49> 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6
RSP: 0018:ffffc90007797638 EFLAGS: 00000202
RAX: 0000000000000002 RBX: ffffffff8fc18ad0 RCX: 0000000000000002
RDX: ffffffff8fc18aa0 RSI: ffffffff9042920e RDI: ffffffff8be33da0
RBP: ffffffff8fc18ac8 R08: 000000000000000d R09: ffffffff8172d195
R10: ffffc90007797758 R11: ffffffff81ac4d00 R12: ffffffff823943a6
R13: ffffffff8fc18ac4 R14: ffffc90007797708 R15: 0000000000000004
 arch_stack_walk+0x11c/0x150
 stack_trace_save+0x9c/0xe0
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_noprof+0x27a/0x4f0
 tomoyo_encode+0x28b/0x550
 tomoyo_realpath_from_path+0x58d/0x5d0
 tomoyo_path_number_perm+0x1e8/0x5a0
 security_file_ioctl+0xcb/0x2d0
 __se_sys_ioctl+0x47/0x170
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7faae1b8eba9
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:00007faae2ada038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007faae1dd5fa0 RCX: 00007faae1b8eba9
RDX: 0000000000000003 RSI: 0000000000002402 RDI: 0000000000000005
RBP: 00007faae1c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007faae1dd6038 R14: 00007faae1dd5fa0 R15: 00007ffdd8d76248
 </TASK>
