syzbot

=============================
WARNING: suspicious RCU usage
6.16.0-syzkaller-08685-g260f6f4fda93 #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-executor419/5824:
 #0: ffffffff8e5c06e0 (rcu_read_lock_trace){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 #0: ffffffff8e5c06e0 (rcu_read_lock_trace){....}-{0:0}, at: rcu_read_lock_trace include/linux/rcupdate_trace.h:58 [inline]
 #0: ffffffff8e5c06e0 (rcu_read_lock_trace){....}-{0:0}, at: bpf_prog_test_run_syscall+0x344/0x780 net/bpf/test_run.c:1563

stack backtrace:
CPU: 1 UID: 0 PID: 5824 Comm: syz-executor419 Not tainted 6.16.0-syzkaller-08685-g260f6f4fda93 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120
 lockdep_rcu_suspicious+0x166/0x260 kernel/locking/lockdep.c:6876
 get_callchain_entry+0x278/0x3f0 kernel/events/callchain.c:163
 get_perf_callchain+0xdb/0x760 kernel/events/callchain.c:227
 __bpf_get_stack+0x4f5/0xa10 kernel/bpf/stackmap.c:454
 ____bpf_get_stack kernel/bpf/stackmap.c:499 [inline]
 bpf_get_stack+0x32/0x40 kernel/bpf/stackmap.c:496
 ____bpf_get_stack_raw_tp kernel/trace/bpf_trace.c:1835 [inline]
 bpf_get_stack_raw_tp+0x1dd/0x280 kernel/trace/bpf_trace.c:1825
 bpf_prog_d43750871481577d+0x46/0x4e
 bpf_dispatcher_nop_func include/linux/bpf.h:1322 [inline]
 __bpf_prog_run include/linux/filter.h:718 [inline]
 bpf_prog_run include/linux/filter.h:725 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:742 [inline]
 bpf_prog_test_run_syscall+0x3ad/0x780 net/bpf/test_run.c:1564
 bpf_prog_test_run kernel/bpf/syscall.c:4583 [inline]
 __sys_bpf+0x104d/0x4de0 kernel/bpf/syscall.c:6040
 __do_sys_bpf kernel/bpf/syscall.c:6132 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:6130 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6130
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1cc616bc39
Code: d8 5b 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffdecebddf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RC