=============================
WARNING: suspicious RCU usage
syzkaller #0 Tainted: G             L     
-----------------------------
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
locks held by syz.4.2531/15605: 1, last CPU#0:
 #0: ffffffff8edeb438 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:314 [inline]
 #0: ffffffff8edeb438 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: rcu_read_lock_trace include/linux/rcupdate_trace.h:101 [inline]
 #0: ffffffff8edeb438 (rcu_tasks_trace_srcu_struct){....}-{0:0}, at: bpf_prog_test_run_syscall+0x301/0xb30 net/bpf/test_run.c:1705

stack backtrace:
CPU: 0 UID: 0 PID: 15605 Comm: syz.4.2531 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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/0xb2 kernel/locking/lockdep.c:6972
 get_callchain_entry+0x278/0x3f0 kernel/events/callchain.c:163
 get_perf_callchain+0x2d6/0x9c0 kernel/events/callchain.c:231
 __bpf_get_stack+0x34a/0x7f0 kernel/bpf/stackmap.c:826
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1692 [inline]
 bpf_get_stack_raw_tp+0x1dd/0x280 kernel/trace/bpf_trace.c:1682
 bpf_prog_aa1f08ea8b241262+0x46/0x4e
 bpf_dispatcher_nop_func include/linux/bpf.h:1452 [inline]
 __bpf_prog_run include/linux/filter.h:779 [inline]
 bpf_prog_run include/linux/filter.h:786 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:803 [inline]
 bpf_prog_test_run_syscall+0x4ba/0xb30 net/bpf/test_run.c:1706
 bpf_prog_test_run kernel/bpf/syscall.c:4804 [inline]
 __sys_bpf+0x2265/0x4a30 kernel/bpf/syscall.c:6385
 __do_sys_bpf kernel/bpf/syscall.c:6486 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6483 [inline]
 __ia32_sys_bpf+0xcc/0x170 kernel/bpf/syscall.c:6483
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline]
 __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf702efec
Code: Unable to access opcode bytes at 0xf702efc2.
RSP: 002b:00000000f541d50c EFLAGS: 00000292 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 00000000800004c0
RDX: 000000000000000c RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>