============================================ WARNING: possible recursive locking detected 6.14.0-rc4-syzkaller-gf77f12010f67 #0 Not tainted -------------------------------------------- syz.0.305/7424 is trying to acquire lock: ffff888025a6f268 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 but task is already holding lock: ffff888024b8ca68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&trie->lock); lock(&trie->lock); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by syz.0.305/7424: #0: ffff88802ae532a0 (&child->perf_event_mutex){+.+.}-{4:4}, at: perf_event_exit_task+0x9b/0xaa0 kernel/events/core.c:13516 #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #1: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2412 #2: ffff888024b8ca68 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline] #3: ffffffff8eb38fa0 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1fc/0x540 kernel/trace/bpf_trace.c:2412 stack backtrace: CPU: 1 UID: 0 PID: 7424 Comm: syz.0.305 Not tainted 6.14.0-rc4-syzkaller-gf77f12010f67 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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:3039 check_deadlock kernel/locking/lockdep.c:3091 [inline] validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3893 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0x170/0x230 include/trace/events/lock.h:122 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0x118/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb7e/0xdb0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [inline] queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x272/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6d0 kernel/bpf/lpm_trie.c:470 bpf_prog_2c29ac5cdc6b1842+0x43/0x47 bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline] __bpf_prog_run include/linux/filter.h:701 [inline] bpf_prog_run include/linux/filter.h:708 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2412 __bpf_trace_contention_end+0x170/0x230 include/trace/events/lock.h:122 __traceiter_contention_end+0x7b/0xb0 include/trace/events/lock.h:122 __do_trace_contention_end include/trace/events/lock.h:122 [inline] trace_contention_end+0xf9/0x120 include/trace/events/lock.h:122 __mutex_lock_common kernel/locking/mutex.c:594 [inline] __mutex_lock+0x38d/0x1010 kernel/locking/mutex.c:730 perf_event_exit_task+0x9b/0xaa0 kernel/events/core.c:13516 do_exit+0xa3a/0x28e0 kernel/exit.c:947 do_group_exit+0x207/0x2c0 kernel/exit.c:1087 __do_sys_exit_group kernel/exit.c:1098 [inline] __se_sys_exit_group kernel/exit.c:1096 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096 x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f60cfd7e719 Code: Unable to access opcode bytes at 0x7f60cfd7e6ef. RSP: 002b:00007ffcb611d968 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f60cfd7e719 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffcb611d9bc R08: 00007ffcb611da4f R09: 000000000001fc24 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000032 R13: 000000000001fc24 R14: 000000000001fc24 R15: 00007ffcb611da10