====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.1418/8642 is trying to acquire lock: ffffffff96ebb450 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:968 [inline] ffffffff96ebb450 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1009 but task is already holding lock: ffff888028798238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xe80 kernel/bpf/lpm_trie.c:335 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&trie->lock){-.-.}-{2:2}: __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467 0xffffffffa00009f2 bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:607 [inline] bpf_prog_run include/linux/filter.h:614 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1d5/0x3e0 kernel/trace/bpf_trace.c:2324 trace_contention_end+0x13f/0x190 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x7e8/0x9c0 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xbc/0x100 kernel/locking/spinlock.c:162 debug_object_deactivate+0x62/0x390 lib/debugobjects.c:753 debug_hrtimer_deactivate kernel/time/hrtimer.c:453 [inline] debug_deactivate+0x29/0x240 kernel/time/hrtimer.c:509 __run_hrtimer kernel/time/hrtimer.c:1715 [inline] __hrtimer_run_queues+0x2eb/0xd70 kernel/time/hrtimer.c:1811 hrtimer_interrupt+0x3c5/0x9c0 kernel/time/hrtimer.c:1873 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 bad_range+0x0/0x2d0 rmqueue mm/page_alloc.c:3887 [inline] get_page_from_freelist+0x1a02/0x1ab0 mm/page_alloc.c:4325 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5614 __alloc_pages_bulk+0x49a/0x920 mm/page_alloc.c:5562 alloc_pages_bulk_array_node include/linux/gfp.h:210 [inline] __page_pool_alloc_pages_slow+0x15a/0x8b0 net/core/page_pool.c:421 page_pool_dev_alloc_pages include/net/page_pool.h:218 [inline] xdp_test_run_batch net/bpf/test_run.c:279 [inline] bpf_test_run_xdp_live+0x61c/0x1a90 net/bpf/test_run.c:362 bpf_prog_test_run_xdp+0x736/0xf10 net/bpf/test_run.c:1407 bpf_prog_test_run+0x31e/0x390 kernel/bpf/syscall.c:3695 __sys_bpf+0x62b/0x780 kernel/bpf/syscall.c:5048 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&obj_hash[i].lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:968 [inline] debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1009 free_pages_prepare mm/page_alloc.c:1465 [inline] __free_pages_ok+0x358/0xc40 mm/page_alloc.c:1715 free_large_kmalloc+0xfd/0x190 mm/slab_common.c:913 trie_update_elem+0x6bf/0xe80 kernel/bpf/lpm_trie.c:444 bpf_map_update_value+0x59e/0x670 kernel/bpf/syscall.c:228 map_update_elem+0x4d7/0x680 kernel/bpf/syscall.c:1473 __sys_bpf+0x4ec/0x780 kernel/bpf/syscall.c:5018 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&trie->lock); lock(&obj_hash[i].lock); lock(&trie->lock); lock(&obj_hash[i].lock); *** DEADLOCK *** 2 locks held by syz.0.1418/8642: #0: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8cb2b2a0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x375/0x670 kernel/bpf/syscall.c:227 #1: ffff888028798238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc7/0xe80 kernel/bpf/lpm_trie.c:335 stack backtrace: CPU: 0 PID: 8642 Comm: syz.0.1418 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106 check_noncircular+0x296/0x330 kernel/locking/lockdep.c:2170 check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain kernel/locking/lockdep.c:3825 [inline] __lock_acquire+0x2d07/0x7d10 kernel/locking/lockdep.c:5049 lock_acquire+0x1bb/0x4a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162 __debug_check_no_obj_freed lib/debugobjects.c:968 [inline] debug_check_no_obj_freed+0x136/0x530 lib/debugobjects.c:1009 free_pages_prepare mm/page_alloc.c:1465 [inline] __free_pages_ok+0x358/0xc40 mm/page_alloc.c:1715 free_large_kmalloc+0xfd/0x190 mm/slab_common.c:913 trie_update_elem+0x6bf/0xe80 kernel/bpf/lpm_trie.c:444 bpf_map_update_value+0x59e/0x670 kernel/bpf/syscall.c:228 map_update_elem+0x4d7/0x680 kernel/bpf/syscall.c:1473 __sys_bpf+0x4ec/0x780 kernel/bpf/syscall.c:5018 __do_sys_bpf kernel/bpf/syscall.c:5134 [inline] __se_sys_bpf kernel/bpf/syscall.c:5132 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5132 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f97abb9acb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f97acaec028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f97abe15fa0 RCX: 00007f97abb9acb9 RDX: 0000000000000020 RSI: 0000200000000180 RDI: 0000000000000002 RBP: 00007f97abc08bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f97abe16038 R14: 00007f97abe15fa0 R15: 00007ffe099c1818