============================================ WARNING: possible recursive locking detected 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Not tainted -------------------------------------------- syz-executor.0/5908 is trying to acquire lock: ffffc900037610d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20d/0x4f0 kernel/bpf/ringbuf.c:424 but task is already holding lock: ffffc900036750d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20d/0x4f0 kernel/bpf/ringbuf.c:424 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.0/5908: #0: ffffffff8d575fa8 (tracepoints_mutex){+.+.}-{3:3}, at: tracepoint_probe_unregister+0x2e/0x980 kernel/tracepoint.c:548 #1: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #1: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #1: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #1: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2420 #2: ffffc900036750d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x20d/0x4f0 kernel/bpf/ringbuf.c:424 #3: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline] #3: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline] #3: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2380 [inline] #3: ffffffff8d52d760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0x110/0x410 kernel/trace/bpf_trace.c:2420 stack backtrace: CPU: 0 PID: 5908 Comm: syz-executor.0 Not tainted 6.8.0-rc7-syzkaller-00229-g10d48d70e82d #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x6a9f/0x7fb0 kernel/locking/lockdep.c:5137 lock_acquire+0x1df/0x520 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x20d/0x4f0 kernel/bpf/ringbuf.c:424 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:459 [inline] bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:451 bpf_prog_9efe54833449f08e+0x25/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] __bpf_prog_run include/linux/filter.h:651 [inline] bpf_prog_run include/linux/filter.h:658 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2420 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xea/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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+0x293/0x3a0 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x20d/0x4f0 kernel/bpf/ringbuf.c:424 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:459 [inline] bpf_ringbuf_reserve+0x58/0x70 kernel/bpf/ringbuf.c:451 bpf_prog_9efe54833449f08e+0x25/0x3f bpf_dispatcher_nop_func include/linux/bpf.h:1231 [inline] __bpf_prog_run include/linux/filter.h:651 [inline] bpf_prog_run include/linux/filter.h:658 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2381 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2420 __traceiter_contention_end+0x74/0xa0 include/trace/events/lock.h:122 trace_contention_end+0xcb/0xf0 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:617 [inline] __mutex_lock+0x2e0/0xd60 kernel/locking/mutex.c:752 tracepoint_probe_unregister+0x2e/0x980 kernel/tracepoint.c:548 bpf_raw_tp_link_release+0x5f/0x80 kernel/bpf/syscall.c:3353 bpf_link_free kernel/bpf/syscall.c:2904 [inline] bpf_link_put_direct+0x11c/0x1b0 kernel/bpf/syscall.c:2935 bpf_link_release+0x37/0x40 kernel/bpf/syscall.c:2942 __fput+0x428/0x890 fs/file_table.c:376 __do_sys_close fs/open.c:1554 [inline] __se_sys_close+0x155/0x1e0 fs/open.c:1539 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x81/0x180 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b RIP: 0033:0x7f019ca7cc9a Code: 48 3d 00 f0 ff ff 77 48 c3 0f 1f 80 00 00 00 00 48 83 ec 18 89 7c 24 0c e8 03 7f 02 00 8b 7c 24 0c 89 c2 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 36 89 d7 89 44 24 0c e8 63 7f 02 00 8b 44 24 RSP: 002b:00007fff32e22c30 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00007f019ca7cc9a RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000005 RBP: 0000000000000226 R08: 0000001b2d060000 R09: 00007f019cbabf8c R10: 00007fff32e22d80 R11: 0000000000000293 R12: 00007f019c6009a0 R13: ffffffffffffffff R14: 00007f019c600000 R15: 0000000000017c44