=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
kernel/events/callchain.c:163 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz.2.882/8440:
 #0: ffffffff8e7e8458 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:317 [inline]
 #0: ffffffff8e7e8458 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: rcu_read_lock_trace include/linux/rcupdate_trace.h:100 [inline]
 #0: ffffffff8e7e8458 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: bpf_prog_test_run_syscall+0x301/0xad0 net/bpf/test_run.c:1639

stack backtrace:
CPU: 3 UID: 0 PID: 8440 Comm: syz.2.882 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
 lockdep_rcu_suspicious.cold+0x4f/0xb1 kernel/locking/lockdep.c:6876
 get_callchain_entry+0x278/0x3f0 kernel/events/callchain.c:163
 get_perf_callchain+0x2d6/0x9c0 kernel/events/callchain.c:231
 __bpf_get_stack+0x531/0xa90 kernel/bpf/stackmap.c:472
 ____bpf_get_stack kernel/bpf/stackmap.c:517 [inline]
 bpf_get_stack+0x32/0x40 kernel/bpf/stackmap.c:514
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1661 [inline]
 bpf_get_stack_raw_tp+0x1dd/0x280 kernel/trace/bpf_trace.c:1651
 bpf_prog_aa1f08ea8b241262+0x46/0x4e
 bpf_dispatcher_nop_func include/linux/bpf.h:1402 [inline]
 __bpf_prog_run include/linux/filter.h:712 [inline]
 bpf_prog_run include/linux/filter.h:730 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:747 [inline]
 bpf_prog_test_run_syscall+0x6e0/0xad0 net/bpf/test_run.c:1640
 bpf_prog_test_run kernel/bpf/syscall.c:4722 [inline]
 __sys_bpf+0x1725/0x4b90 kernel/bpf/syscall.c:6246
 __do_sys_bpf kernel/bpf/syscall.c:6341 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6339 [inline]
 __ia32_sys_bpf+0x79/0xf0 kernel/bpf/syscall.c:6339
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe3/0x8c0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf706ef6c
Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 58 b8 77 00 00 00 cd 80 0f 0b 8d b6 00 00 00 00 b8 ad
RSP: 002b:00000000f545d50c EFLAGS: 00000292 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000080000740
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess):
   0:	d2 74 05 c1          	shlb   %cl,-0x3f(%rbp,%rax,1)
   4:	e8 0c 89 02 8b       	call   0x8b028915
   9:	5d                   	pop    %rbp
   a:	fc                   	cld
   b:	31 c0                	xor    %eax,%eax
   d:	c9                   	leave
   e:	c3                   	ret
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	0f 1f 00             	nopl   (%rax)
  21:	51                   	push   %rcx
  22:	52                   	push   %rdx
  23:	55                   	push   %rbp
  24:	89 e5                	mov    %esp,%ebp
  26:	0f 34                	sysenter
  28:	cd 80                	int    $0x80
* 2a:	5d                   	pop    %rbp <-- trapping instruction
  2b:	5a                   	pop    %rdx
  2c:	59                   	pop    %rcx
  2d:	c3                   	ret
  2e:	58                   	pop    %rax
  2f:	b8 77 00 00 00       	mov    $0x77,%eax
  34:	cd 80                	int    $0x80
  36:	0f 0b                	ud2
  38:	8d b6 00 00 00 00    	lea    0x0(%rsi),%esi
  3e:	b8                   	.byte 0xb8
  3f:	ad                   	lods   %ds:(%rsi),%eax