====================================================== WARNING: possible circular locking dependency detected 6.6.102-syzkaller #0 Not tainted ------------------------------------------------------ syz.1.215/6509 is trying to acquire lock: ffff888023c60238 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:467 but task is already holding lock: ffff8880178409d8 (&n->list_lock){-.-.}-{2:2}, at: __unfreeze_partials+0x7f/0x210 mm/slub.c:2626 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&n->list_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 get_partial_node+0x36/0x540 mm/slub.c:2296 get_partial mm/slub.c:2411 [inline] ___slab_alloc+0x9cd/0x12f0 mm/slub.c:3225 __slab_alloc mm/slub.c:3329 [inline] __slab_alloc_node mm/slub.c:3382 [inline] slab_alloc_node mm/slub.c:3475 [inline] __kmem_cache_alloc_node+0x1a2/0x260 mm/slub.c:3524 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node+0xa4/0x230 mm/slab_common.c:1014 kmalloc_node include/linux/slab.h:620 [inline] bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x166/0xea0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x660/0x720 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_ae0c3e605f35524c+0x45/0x49 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 __unfreeze_partials+0x7f/0x210 mm/slub.c:2626 put_cpu_partial+0x17c/0x250 mm/slub.c:2738 __slab_free+0x31d/0x410 mm/slub.c:3686 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 ptlock_alloc mm/memory.c:6155 [inline] ptlock_init include/linux/mm.h:2898 [inline] pmd_ptlock_init include/linux/mm.h:2998 [inline] pagetable_pmd_ctor include/linux/mm.h:3036 [inline] pmd_alloc_one include/asm-generic/pgalloc.h:137 [inline] __pmd_alloc+0x116/0x880 mm/memory.c:5577 pmd_alloc include/linux/mm.h:2797 [inline] __handle_mm_fault mm/memory.c:5127 [inline] handle_mm_fault+0xb3d/0x4920 mm/memory.c:5331 do_user_addr_fault+0xad0/0x12e0 arch/x86/mm/fault.c:1324 handle_page_fault arch/x86/mm/fault.c:1465 [inline] exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 other info that might help us debug this: Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&n->list_lock); lock(&trie->lock); lock(&n->list_lock); lock(&trie->lock); *** DEADLOCK *** 4 locks held by syz.1.215/6509: #0: ffff88802f543808 (&vma->vm_lock->lock){++++}-{3:3}, at: vma_start_read include/linux/mm.h:669 [inline] #0: ffff88802f543808 (&vma->vm_lock->lock){++++}-{3:3}, at: lock_vma_under_rcu+0x23b/0x650 mm/memory.c:5487 #1: ffffffff8ce2cfe0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:116 [inline] #1: ffffffff8ce2cfe0 (remove_cache_srcu){.+.+}-{0:0}, at: srcu_read_lock+0x24/0x50 include/linux/srcu.h:215 #2: ffff8880178409d8 (&n->list_lock){-.-.}-{2:2}, at: __unfreeze_partials+0x7f/0x210 mm/slub.c:2626 #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline] #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline] #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline] #3: ffffffff8cd2fbe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361 stack backtrace: CPU: 1 PID: 6509 Comm: syz.1.215 Not tainted 6.6.102-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_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_ae0c3e605f35524c+0x45/0x49 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 __unfreeze_partials+0x7f/0x210 mm/slub.c:2626 put_cpu_partial+0x17c/0x250 mm/slub.c:2738 __slab_free+0x31d/0x410 mm/slub.c:3686 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xe0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3485 [inline] slab_alloc mm/slub.c:3493 [inline] __kmem_cache_alloc_lru mm/slub.c:3500 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3509 ptlock_alloc mm/memory.c:6155 [inline] ptlock_init include/linux/mm.h:2898 [inline] pmd_ptlock_init include/linux/mm.h:2998 [inline] pagetable_pmd_ctor include/linux/mm.h:3036 [inline] pmd_alloc_one include/asm-generic/pgalloc.h:137 [inline] __pmd_alloc+0x116/0x880 mm/memory.c:5577 pmd_alloc include/linux/mm.h:2797 [inline] __handle_mm_fault mm/memory.c:5127 [inline] handle_mm_fault+0xb3d/0x4920 mm/memory.c:5331 do_user_addr_fault+0xad0/0x12e0 arch/x86/mm/fault.c:1324 handle_page_fault arch/x86/mm/fault.c:1465 [inline] exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f2c24a65723 Code: 8b 44 24 68 8b b4 24 98 00 00 00 89 30 e9 01 fb ff ff 48 89 c2 48 8d 35 34 dd 1a 00 48 8d 3d ea dd 1a 00 31 c0 e8 1d 99 fe ff <89> 32 e9 b8 ef ff ff 48 8d 05 1f 50 23 00 48 8d 3d e8 ff e7 00 c6 RSP: 002b:00007ffc7333b600 EFLAGS: 00010246 RAX: 00000000003ffde8 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000001b31024000 RSI: 0000000000400000 RDI: 00007f2c24c9a750 RBP: 0000000000000000 R08: 0000000000000004 R09: 0000000000040000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000051c52 R15: 00007ffc7333b8b0