syzbot

=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
kernel/events/callchain.c:161 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.0.17/5929:
 #0: ffffffff8d1322c0 (rcu_read_lock_trace){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1322c0 (rcu_read_lock_trace){....}-{0:0}, at: rcu_read_lock_trace+0x37/0x70 include/linux/rcupdate_trace.h:57

stack backtrace:
CPU: 0 PID: 5929 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 lockdep_rcu_suspicious+0x1e1/0x300 kernel/locking/lockdep.c:6731
 get_callchain_entry+0x2a9/0x3c0 kernel/events/callchain.c:161
 get_perf_callchain+0xc6/0x510 kernel/events/callchain.c:191
 __bpf_get_stack+0x2e4/0x540 kernel/bpf/stackmap.c:435
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1917 [inline]
 bpf_get_stack_raw_tp+0x1a9/0x210 kernel/trace/bpf_trace.c:1907
 bpf_prog_14d9fb3786f83342+0x45/0x49
 bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
 __bpf_prog_run include/linux/filter.h:616 [inline]
 bpf_prog_run include/linux/filter.h:623 [inline]
 bpf_prog_run_pin_on_cpu+0x64/0x150 include/linux/filter.h:640
 bpf_prog_test_run_syscall+0x317/0x4a0 net/bpf/test_run.c:1524
 bpf_prog_test_run+0x321/0x390 kernel/bpf/syscall.c:4132
 __sys_bpf+0x49d/0x890 kernel/bpf/syscall.c:5495
 __do_sys_bpf kernel/bpf/syscall.c:5581 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5579 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5579
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc72e79cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe4f6287a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fc72ea15fa0 RCX: 00007fc72e79cdd9
RDX: 0000000000000010 RSI: 0000200000000740 RDI: 000000000000000a
RBP: 00007fc72e832d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fc72ea15fac R14: 00007fc72ea15fa0 R15: 00007fc72ea15fa0
 </TASK>