============================================ WARNING: possible recursive locking detected syzkaller #0 Not tainted -------------------------------------------- syz-execprog/5788 is trying to acquire lock: ffffc9000c1490d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423 but task is already holding lock: ffffc9000c1190d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423 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-execprog/5788: #0: ffff8880b8f3c458 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:558 #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #1: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 #2: ffffc9000c1190d8 (&rb->spinlock){-.-.}-{2:2}, at: __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423 #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x690 kernel/trace/bpf_trace.c:142 stack backtrace: CPU: 1 PID: 5788 Comm: syz-execprog Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_deadlock kernel/locking/lockdep.c:3062 [inline] validate_chain kernel/locking/lockdep.c:3856 [inline] __lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466 bpf_prog_df2ea1bb7efca089+0x35/0x4f bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] bpf_prog_run_array include/linux/bpf.h:1993 [inline] trace_call_bpf+0x321/0x690 kernel/trace/bpf_trace.c:143 perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10262 perf_trace_contention_begin+0x254/0x2f0 include/trace/events/lock.h:95 trace_contention_begin+0xe9/0x110 include/trace/events/lock.h:95 __pv_queued_spin_lock_slowpath+0xe0/0x9d0 kernel/locking/qspinlock.c:405 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+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162 __bpf_ringbuf_reserve+0x1c8/0x5a0 kernel/bpf/ringbuf.c:423 ____bpf_ringbuf_reserve kernel/bpf/ringbuf.c:474 [inline] bpf_ringbuf_reserve+0x5c/0x70 kernel/bpf/ringbuf.c:466 bpf_prog_6979e45824a16319+0x35/0x61 bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline] bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361 __bpf_trace_tlb_flush+0xf6/0x150 include/trace/events/tlb.h:38 __traceiter_tlb_flush+0x6d/0xc0 include/trace/events/tlb.h:38 trace_tlb_flush+0xea/0x110 include/trace/events/tlb.h:38 switch_mm_irqs_off+0x7aa/0xb10 arch/x86/mm/tlb.c:-1 context_switch kernel/sched/core.c:5364 [inline] __schedule+0xf22/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 do_nanosleep+0x1ad/0x5f0 kernel/time/hrtimer.c:2114 hrtimer_nanosleep+0x15f/0x350 kernel/time/hrtimer.c:2162 __do_sys_nanosleep kernel/time/hrtimer.c:2197 [inline] __se_sys_nanosleep kernel/time/hrtimer.c:2183 [inline] __x64_sys_nanosleep+0x22d/0x290 kernel/time/hrtimer.c:2183 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x47fad7 Code: Unable to access opcode bytes at 0x47faad. RSP: 002b:000000c00005ff18 EFLAGS: 00000202 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 0000000000000014 RCX: 000000000047fad7 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000c00005ff18 RBP: 000000c00005ff28 R08: 0000000000000000 R09: 000000000000002a R10: 0000003130cea16f R11: 0000000000000202 R12: 000000c00005ff18 R13: 000000c00007e008 R14: 000000c000002700 R15: 000000c000002700