syzbot

============================================
WARNING: possible recursive locking detected
6.1.147-syzkaller #0 Not tainted
--------------------------------------------
syz-executor/4391 is trying to acquire lock:
ffffc900050510d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c4/0x5a0 kernel/bpf/ringbuf.c:413

but task is already holding lock:
ffffc900052ed0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c4/0x5a0 kernel/bpf/ringbuf.c:413

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-executor/4391:
 #0: ffffffff8de7a808 (ebt_mutex){+.+.}-{3:3}, at: find_inlist_lock_noload+0x4d/0x260 net/bridge/netfilter/ebtables.c:328
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #1: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324
 #2: ffffc900052ed0d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c4/0x5a0 kernel/bpf/ringbuf.c:413
 #3: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #3: ffffffff8cb2ae20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xda/0x3b0 kernel/trace/bpf_trace.c:2324

stack backtrace:
CPU: 0 PID: 4391 Comm: syz-executor Not tainted 6.1.147-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 __lock_acquire+0x122f/0x7c50 kernel/locking/lockdep.c:-1
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1c4/0x5a0 kernel/bpf/ringbuf.c:413
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:464 [inline]
 bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:456
 bpf_prog_fe0ed97373b08409+0x25/0x42
 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122
 __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
 do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
 _raw_spin_lock_irqsave+0xb0/0xf0 kernel/locking/spinlock.c:162
 __bpf_ringbuf_reserve+0x1c4/0x5a0 kernel/bpf/ringbuf.c:413
 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:464 [inline]
 bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:456
 bpf_prog_fe0ed97373b08409+0x25/0x42
 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [inline]
 __bpf_prog_run include/linux/filter.h:603 [inline]
 bpf_prog_run include/linux/filter.h:610 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline]
 bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324
 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122
 trace_contention_end+0x123/0x170 include/trace/events/lock.h:122
 __mutex_lock_common kernel/locking/mutex.c:612 [inline]
 __mutex_lock+0x194/0xaf0 kernel/locking/mutex.c:747
 find_inlist_lock_noload+0x4d/0x260 net/bridge/netfilter/ebtables.c:328
 find_inlist_lock net/bridge/netfilter/ebtables.c:370 [inline]
 find_table_lock net/bridge/netfilter/ebtables.c:379 [inline]
 do_ebt_get_ctl+0x255/0x1c00 net/bridge/netfilter/ebtables.c:2468
 nf_getsockopt+0x25e/0x280 net/netfilter/nf_sockopt.c:116
 ip_getsockopt+0x1bd/0x210 net/ipv4/ip_sockglue.c:1826
 __sys_getsockopt+0x1b0/0x230 net/socket.c:2332
 __do_sys_getsockopt net/socket.c:2347 [inline]
 __se_sys_getsockopt net/socket.c:2344 [inline]
 __x64_sys_getsockopt+0xb1/0xc0 net/socket.c:2344
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f214c59092a
Code: ff c3 66 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 b8 ff ff ff ff eb b8 0f 1f 44 00 00 49 89 ca b8 37 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 c7 c2 a8 ff ff ff f7
RSP: 002b:00007fffda24d918 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 00007f214c782000 RCX: 00007f214c59092a
RDX: 0000000000000080 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fffda24d93c R09: 00007fffda24dd47
R10: 00007fffda24d940 R11: 0000000000000246 R12: 00007fffda24d940
R13: 00007fffda24d93c R14: 0000000000000002 R15: 0000000000000000
 </TASK>