====================================================== WARNING: possible circular locking dependency detected syzkaller #0 Not tainted ------------------------------------------------------ syz.0.3277/13478 is trying to acquire lock: ffff888017440d98 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node+0x36/0x470 mm/slub.c:2215 but task is already holding lock: ffff88804c0eaa38 (&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 0xffffffffa00009da 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 __unfreeze_partials+0x71/0x200 mm/slub.c:2555 put_cpu_partial+0x17c/0x250 mm/slub.c:2667 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x76/0xe0 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x144/0x160 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x1e/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook+0x4b/0x480 mm/slab.h:737 slab_alloc_node mm/slub.c:3359 [inline] slab_alloc mm/slub.c:3367 [inline] __kmem_cache_alloc_lru mm/slub.c:3374 [inline] kmem_cache_alloc+0x123/0x2f0 mm/slub.c:3383 kmem_cache_zalloc include/linux/slab.h:689 [inline] lsm_file_alloc security/security.c:575 [inline] security_file_alloc+0x30/0x110 security/security.c:1543 __alloc_file+0xc2/0x230 fs/file_table.c:143 alloc_empty_file+0x90/0x180 fs/file_table.c:187 alloc_file+0x5c/0x5f0 fs/file_table.c:229 alloc_file_pseudo+0x180/0x200 fs/file_table.c:272 __anon_inode_getfile fs/anon_inodes.c:122 [inline] anon_inode_getfile+0xc1/0x1a0 fs/anon_inodes.c:160 __do_sys_perf_event_open kernel/events/core.c:12604 [inline] __se_sys_perf_event_open+0xc26/0x1ec0 kernel/events/core.c:12378 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 (&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 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 get_partial_node+0x36/0x470 mm/slub.c:2215 get_partial mm/slub.c:2330 [inline] ___slab_alloc+0x968/0x1240 mm/slub.c:3131 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa0/0x240 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] bpf_map_kmalloc_node+0xb8/0x1a0 kernel/bpf/syscall.c:454 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x163/0xe80 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x59e/0x670 kernel/bpf/syscall.c:228 generic_map_update_batch+0x54b/0x810 kernel/bpf/syscall.c:1709 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x6f7/0x780 kernel/bpf/syscall.c:-1 __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(&n->list_lock); lock(&trie->lock); lock(&n->list_lock); *** DEADLOCK *** 2 locks held by syz.0.3277/13478: #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: ffff88804c0eaa38 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc7/0xe80 kernel/bpf/lpm_trie.c:335 stack backtrace: CPU: 1 PID: 13478 Comm: syz.0.3277 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 get_partial_node+0x36/0x470 mm/slub.c:2215 get_partial mm/slub.c:2330 [inline] ___slab_alloc+0x968/0x1240 mm/slub.c:3131 __slab_alloc mm/slub.c:3240 [inline] slab_alloc_node mm/slub.c:3325 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3398 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc_node+0xa0/0x240 mm/slab_common.c:943 kmalloc_node include/linux/slab.h:589 [inline] bpf_map_kmalloc_node+0xb8/0x1a0 kernel/bpf/syscall.c:454 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline] trie_update_elem+0x163/0xe80 kernel/bpf/lpm_trie.c:338 bpf_map_update_value+0x59e/0x670 kernel/bpf/syscall.c:228 generic_map_update_batch+0x54b/0x810 kernel/bpf/syscall.c:1709 bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1 __sys_bpf+0x6f7/0x780 kernel/bpf/syscall.c:-1 __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: 0033:0x7f5d82d9acb9 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:00007f5d83bf6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f5d83015fa0 RCX: 00007f5d82d9acb9 RDX: 0000000000000038 RSI: 0000200000000680 RDI: 000000000000001a RBP: 00007f5d82e08bf7 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5d83016038 R14: 00007f5d83015fa0 R15: 00007ffdefd0f0f8