============================================ WARNING: possible recursive locking detected 6.12.0-rc4-syzkaller-00168-gd0b98f6a17a5 #0 Not tainted -------------------------------------------- syz.2.301/6733 is trying to acquire lock: ffffc90003d980d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 but task is already holding lock: ffffc90003d840d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 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 3 locks held by syz.2.301/6733: #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: sk_psock_verdict_recv+0x4d/0x590 net/core/skmsg.c:1186 #1: ffffc90003d840d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 #2: ffffffff8e937e20 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xbc/0x8a0 stack backtrace: CPU: 0 UID: 0 PID: 6733 Comm: syz.2.301 Not tainted 6.12.0-rc4-syzkaller-00168-gd0b98f6a17a5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037 check_deadlock kernel/locking/lockdep.c:3089 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1ea/0x600 kernel/bpf/ringbuf.c:427 ____bpf_ringbuf_output kernel/bpf/ringbuf.c:553 [inline] bpf_ringbuf_output+0x67/0x1e0 kernel/bpf/ringbuf.c:543 bpf_prog_224b060aaa884769+0x47/0x4b bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] bpf_prog_run_array include/linux/bpf.h:2131 [inline] trace_call_bpf+0x369/0x8a0 kernel/trace/bpf_trace.c:146 perf_trace_run_bpf_submit+0x82/0x180 kernel/events/core.c:10416 perf_trace_lock+0x388/0x490 include/trace/events/lock.h:50 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x9cc/0xa30 kernel/locking/lockdep.c:5836 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x79/0x140 kernel/locking/spinlock.c:194 __bpf_ringbuf_reserve+0x4ad/0x600 kernel/bpf/ringbuf.c:453 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:478 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:470 bpf_prog_f93567782984e510+0x2e/0x48 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:725 [inline] sk_psock_verdict_recv+0x2cd/0x590 net/core/skmsg.c:1200 unix_stream_read_skb+0x13c/0x350 net/unix/af_unix.c:2750 sk_psock_verdict_data_ready+0xab/0x390 net/core/skmsg.c:1224 unix_stream_sendmsg+0x7d5/0xf80 net/unix/af_unix.c:2345 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607 ___sys_sendmsg net/socket.c:2661 [inline] __sys_sendmsg+0x292/0x380 net/socket.c:2690 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f271637e719 Code: ff ff 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f27171d6038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2716535f80 RCX: 00007f271637e719 RDX: 0000000000000000 RSI: 00000000200029c0 RDI: 0000000000000005 RBP: 00007f27163f132e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2716535f80 R15: 00007ffe980bf2a8