syzbot

============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
syz.0.679/6683 is trying to acquire lock:
ffffc900050450d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d6/0x5c0 kernel/bpf/ringbuf.c:425

but task is already holding lock:
ffffc90004e350d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d6/0x5c0 kernel/bpf/ringbuf.c:425

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(&rb->spinlock);
  lock(&rb->spinlock);

 *** DEADLOCK ***

 May be due to missing lock nesting notation

4 locks held by syz.0.679/6683:
 #0: ffffffff8d17a708 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_unregister+0x30/0x930 kernel/tracepoint.c:548
 #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
 #1: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xe6/0x3e0 kernel/trace/bpf_trace.c:2361
 #2: ffffc90004e350d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1d6/0x5c0 kernel/bpf/ringbuf.c:425
 #3: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #3: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #3: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
 #3: ffffffff8d131fe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xe6/0x3e0 kernel/trace/bpf_trace.c:2361

stack backtrace:
CPU: 0 PID: 6683 Comm: syz.0.679 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_deadlock kernel/locking/lockdep.c:3062 [inline]
 validate_chain kernel/locking/lockdep.c:3856 [inline]
 __lock_acquire+0x5dbc/0x7d40 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1d6/0x5c0 kernel/bpf/ringbuf.c:425
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:476 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:468
 bpf_prog_fe0ed97373b08409+0x2d/0x4a
 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_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run2+0x1d9/0x3e0 kernel/trace/bpf_trace.c:2361
 __bpf_trace_contention_end+0x105/0x150 include/trace/events/lock.h:122
 __traceiter_contention_end+0x78/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0xe2/0x100 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x23e/0x2c0 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xc0/0x100 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1d6/0x5c0 kernel/bpf/ringbuf.c:425
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:476 [inline]
 bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:468
 bpf_prog_fe0ed97373b08409+0x2d/0x4a
 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_trace_run kernel/trace/bpf_trace.c:2322 [inline]
 bpf_trace_run2+0x1d9/0x3e0 kernel/trace/bpf_trace.c:2361
 __bpf_trace_contention_end+0x105/0x150 include/trace/events/lock.h:122
 __traceiter_contention_end+0x78/0xb0 include/trace/events/lock.h:122
 trace_contention_end+0xc1/0xe0 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:612 [inline]
 __mutex_lock+0x30b/0xcc0 kernel/locking/mutex.c:747
 tracepoint_probe_unregister+0x30/0x930 kernel/tracepoint.c:548
 bpf_raw_tp_link_release+0x63/0x90 kernel/bpf/syscall.c:3378
 bpf_link_free+0x131/0x310 kernel/bpf/syscall.c:2921
 bpf_link_put_direct kernel/bpf/syscall.c:2961 [inline]
 bpf_link_release+0x6e/0x80 kernel/bpf/syscall.c:2968
 __fput+0x234/0x970 fs/file_table.c:384
 task_work_run+0x1d4/0x260 kernel/task_work.c:245
 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
 exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
 syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
 do_syscall_64+0x61/0xa0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f4e8219acb9
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:00007ffdc3b14d48 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007ffdc3b14e30 RCX: 00007f4e8219acb9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 0000000000043d75 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b2d420000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f4e82415fac R14: 00007f4e82415fa8 R15: 00007f4e82415fa0
 </TASK>