====================================================== WARNING: possible circular locking dependency detected 6.1.131-syzkaller #0 Not tainted ------------------------------------------------------ syz.4.300/5302 is trying to acquire lock: ffff888017c43318 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node+0x36/0x450 mm/slub.c:2210 but task is already holding lock: ffff8880558a7238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc6/0xdc0 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}: lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:467 0xffffffffa0001fe7 bpf_dispatcher_nop_func include/linux/bpf.h:1000 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline] bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2323 trace_contention_end+0x14c/0x190 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [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+0x269/0x370 kernel/locking/spinlock_debug.c:115 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162 get_partial_node+0x36/0x450 mm/slub.c:2210 get_partial mm/slub.c:2325 [inline] ___slab_alloc+0x9b2/0x1270 mm/slub.c:3175 kmem_cache_alloc_bulk+0x19d/0x4d0 mm/slub.c:3830 mt_alloc_bulk lib/maple_tree.c:157 [inline] mas_alloc_nodes+0x3df/0x800 lib/maple_tree.c:1299 mas_node_count_gfp lib/maple_tree.c:1359 [inline] mas_preallocate+0x12d/0x350 lib/maple_tree.c:5805 __vma_adjust+0x8df/0x1f40 mm/mmap.c:723 __split_vma+0x36c/0x4c0 do_mas_align_munmap+0x95f/0x15a0 mm/mmap.c:2489 do_mas_munmap+0x246/0x2b0 mm/mmap.c:2638 __mmap_region mm/mmap.c:2686 [inline] mmap_region+0x8d4/0x2660 mm/mmap.c:2904 do_mmap+0x8c5/0xf60 mm/mmap.c:1424 vm_mmap_pgoff+0x1ca/0x2d0 mm/util.c:520 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 -> #0 (&n->list_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3090 [inline] check_prevs_add kernel/locking/lockdep.c:3209 [inline] validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 get_partial_node+0x36/0x450 mm/slub.c:2210 get_partial mm/slub.c:2325 [inline] ___slab_alloc+0x9b2/0x1270 mm/slub.c:3175 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa2/0x230 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] bpf_map_kmalloc_node+0xce/0x1c0 kernel/bpf/syscall.c:452 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x175/0xdc0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1463 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:5005 __do_sys_bpf kernel/bpf/syscall.c:5121 [inline] __se_sys_bpf kernel/bpf/syscall.c:5119 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5119 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/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(&trie->lock); lock(&n->list_lock); lock(&trie->lock); lock(&n->list_lock); *** DEADLOCK *** 2 locks held by syz.4.300/5302: #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline] #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline] #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x207/0x6f0 kernel/bpf/syscall.c:225 #1: ffff8880558a7238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc6/0xdc0 kernel/bpf/lpm_trie.c:335 stack backtrace: CPU: 1 PID: 5302 Comm: syz.4.300 Not tainted 6.1.131-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 check_noncircular+0x2fa/0x3b0 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+0x1661/0x5950 kernel/locking/lockdep.c:3825 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162 get_partial_node+0x36/0x450 mm/slub.c:2210 get_partial mm/slub.c:2325 [inline] ___slab_alloc+0x9b2/0x1270 mm/slub.c:3175 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x19f/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa2/0x230 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] bpf_map_kmalloc_node+0xce/0x1c0 kernel/bpf/syscall.c:452 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x175/0xdc0 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1463 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:5005 __do_sys_bpf kernel/bpf/syscall.c:5121 [inline] __se_sys_bpf kernel/bpf/syscall.c:5119 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5119 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f69a9d8d169 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:00007f69aab58038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f69a9fa5fa0 RCX: 00007f69a9d8d169 RDX: 0000000000000020 RSI: 00002000000004c0 RDI: 0000000000000002 RBP: 00007f69a9e0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f69a9fa5fa0 R15: 00007ffc12afbc48