====================================================== WARNING: possible circular locking dependency detected 6.6.93-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.495/6892 is trying to acquire lock: ffff88805c071238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffffffff9714e068 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&obj_hash[i].lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:979 [inline] debug_check_no_obj_freed+0x13a/0x540 lib/debugobjects.c:1020 slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0xd2/0x1b0 mm/slub.c:1832 slab_free mm/slub.c:3816 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3829 trie_update_elem+0x6d1/0xea0 kernel/bpf/lpm_trie.c:444 bpf_map_update_value+0x67c/0x740 kernel/bpf/syscall.c:201 map_update_elem+0x57b/0x700 kernel/bpf/syscall.c:1561 __sys_bpf+0x652/0x800 kernel/bpf/syscall.c:5455 __do_sys_bpf kernel/bpf/syscall.c:5571 [inline] __se_sys_bpf kernel/bpf/syscall.c:5569 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569 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 -> #0 (&trie->lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/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 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_41385012b43a9f2e+0x48/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1213 [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_contention_end+0xdd/0x130 include/trace/events/lock.h:122 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560 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 debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline] debug_activate kernel/time/hrtimer.c:505 [inline] enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1113 __run_hrtimer kernel/time/hrtimer.c:1772 [inline] __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 should_resched arch/x86/include/asm/preempt.h:104 [inline] __local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:413 spin_unlock_bh include/linux/spinlock.h:396 [inline] sock_hash_delete_elem+0x27d/0x2e0 net/core/sock_map.c:957 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:636 [inline] bpf_flow_dissect+0x12f/0x3e0 net/core/flow_dissector.c:1000 bpf_prog_test_run_flow_dissector+0x40d/0x600 net/bpf/test_run.c:1353 bpf_prog_test_run+0x321/0x390 kernel/bpf/syscall.c:4123 __sys_bpf+0x440/0x800 kernel/bpf/syscall.c:5485 __do_sys_bpf kernel/bpf/syscall.c:5571 [inline] __se_sys_bpf kernel/bpf/syscall.c:5569 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569 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 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&obj_hash[i].lock); lock(&trie->lock); lock(&obj_hash[i].lock); lock(&trie->lock); *** DEADLOCK *** 4 locks held by syz.1.495/6892: #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #0: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_test_timer_enter+0x1a/0x140 net/bpf/test_run.c:39 #1: ffff8880b8e2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1759 [inline] #1: ffff8880b8e2b958 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1819 #2: ffffffff9714e068 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #3: ffffffff8cd2f760 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 0 PID: 6892 Comm: syz.1.495 Not tainted 6.6.93-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106 check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187 check_prev_add kernel/locking/lockdep.c:3134 [inline] check_prevs_add kernel/locking/lockdep.c:3253 [inline] validate_chain kernel/locking/lockdep.c:3869 [inline] __lock_acquire+0x2ddb/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 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 bpf_prog_41385012b43a9f2e+0x48/0x4c bpf_dispatcher_nop_func include/linux/bpf.h:1213 [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_contention_end+0xdd/0x130 include/trace/events/lock.h:122 trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560 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 debug_object_activate+0x6c/0x4b0 lib/debugobjects.c:709 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline] debug_activate kernel/time/hrtimer.c:505 [inline] enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1113 __run_hrtimer kernel/time/hrtimer.c:1772 [inline] __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:should_resched arch/x86/include/asm/preempt.h:104 [inline] RIP: 0010:__local_bh_enable_ip+0x136/0x1c0 kernel/softirq.c:413 Code: 8a e8 5e ac 14 09 65 66 8b 05 e6 38 b2 7e 66 85 c0 75 54 bf 01 00 00 00 e8 a7 e2 09 00 e8 82 78 3a 00 fb 65 8b 05 b2 38 b2 7e <85> c0 75 05 e8 91 1a af ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00 RSP: 0018:ffffc90004c27a60 EFLAGS: 00000286 RAX: 0000000080000001 RBX: 0000000000000201 RCX: 13c41dd0561a5c00 RDX: dffffc0000000000 RSI: ffffffff8aaab2c0 RDI: ffffffff8afc6780 RBP: ffffc90004c27ae8 R08: ffffffff8e49a76f R09: 1ffffffff1c934ed R10: dffffc0000000000 R11: fffffbfff1c934ee R12: ffffffff887a0ced R13: 0000000000000006 R14: dffffc0000000000 R15: 1ffff92000984f4c spin_unlock_bh include/linux/spinlock.h:396 [inline] sock_hash_delete_elem+0x27d/0x2e0 net/core/sock_map.c:957 bpf_prog_2c29ac5cdc6b1842+0x42/0x46 bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline] __bpf_prog_run include/linux/filter.h:612 [inline] bpf_prog_run include/linux/filter.h:619 [inline] bpf_prog_run_pin_on_cpu include/linux/filter.h:636 [inline] bpf_flow_dissect+0x12f/0x3e0 net/core/flow_dissector.c:1000 bpf_prog_test_run_flow_dissector+0x40d/0x600 net/bpf/test_run.c:1353 bpf_prog_test_run+0x321/0x390 kernel/bpf/syscall.c:4123 __sys_bpf+0x440/0x800 kernel/bpf/syscall.c:5485 __do_sys_bpf kernel/bpf/syscall.c:5571 [inline] __se_sys_bpf kernel/bpf/syscall.c:5569 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569 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: 0033:0x7f231398e929 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:00007f231474b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f2313bb5fa0 RCX: 00007f231398e929 RDX: 0000000000000050 RSI: 0000200000000180 RDI: 000000000000000a RBP: 00007f2313a10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2313bb5fa0 R15: 00007ffc909f0558 ---------------- Code disassembly (best guess): 0: 8a e8 mov %al,%ch 2: 5e pop %rsi 3: ac lods %ds:(%rsi),%al 4: 14 09 adc $0x9,%al 6: 65 66 8b 05 e6 38 b2 mov %gs:0x7eb238e6(%rip),%ax # 0x7eb238f4 d: 7e e: 66 85 c0 test %ax,%ax 11: 75 54 jne 0x67 13: bf 01 00 00 00 mov $0x1,%edi 18: e8 a7 e2 09 00 call 0x9e2c4 1d: e8 82 78 3a 00 call 0x3a78a4 22: fb sti 23: 65 8b 05 b2 38 b2 7e mov %gs:0x7eb238b2(%rip),%eax # 0x7eb238dc * 2a: 85 c0 test %eax,%eax <-- trapping instruction 2c: 75 05 jne 0x33 2e: e8 91 1a af ff call 0xffaf1ac4 33: 48 c7 04 24 0e 36 e0 movq $0x45e0360e,(%rsp) 3a: 45 3b: 4b rex.WXB 3c: c7 .byte 0xc7 3d: 04 37 add $0x37,%al