====================================================== WARNING: possible circular locking dependency detected 6.10.0-syzkaller-12687-g35ec1cdfc3fe #0 Not tainted ------------------------------------------------------ syz.1.69/5560 is trying to acquire lock: ffff88801584e6d8 (&n->list_lock){-.-.}-{2:2}, at: get_partial_node+0x36/0x280 mm/slub.c:2732 but task is already holding lock: ffff88807a2c2200 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&trie->lock){..-.}-{2:2}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462 0xffffffffa0001e5f bpf_dispatcher_nop_func include/linux/bpf.h:1252 [inline] __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run include/linux/filter.h:698 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2338 [inline] bpf_trace_run2+0x2ec/0x540 kernel/trace/bpf_trace.c:2379 trace_contention_end+0x114/0x140 include/trace/events/lock.h:122 __pv_queued_spin_lock_slowpath+0xb81/0xdc0 kernel/locking/qspinlock.c:557 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:584 [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+0x272/0x370 kernel/locking/spinlock_debug.c:116 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline] _raw_spin_lock_irqsave+0xe1/0x120 kernel/locking/spinlock.c:162 __slab_free+0xec/0x3d0 mm/slub.c:4319 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_noprof+0x1d2/0x440 mm/slub.c:4164 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:650 seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x202/0xd60 fs/seq_file.c:210 new_sync_read fs/read_write.c:395 [inline] vfs_read+0x9bd/0xbc0 fs/read_write.c:476 ksys_read+0x1a0/0x2c0 fs/read_write.c:619 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&n->list_lock){-.-.}-{2:2}: check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 get_partial_node+0x36/0x280 mm/slub.c:2732 get_partial mm/slub.c:2846 [inline] ___slab_alloc+0xc17/0x14b0 mm/slub.c:3703 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4164 kmalloc_node_noprof include/linux/slab.h:708 [inline] bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1654 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5698 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f 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.1.69/5560: #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline] #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8e937660 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202 #1: ffff88807a2c2200 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333 stack backtrace: CPU: 0 UID: 0 PID: 5560 Comm: syz.1.69 Not tainted 6.10.0-syzkaller-12687-g35ec1cdfc3fe #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Call Trace: __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2186 check_prev_add kernel/locking/lockdep.c:3133 [inline] check_prevs_add kernel/locking/lockdep.c:3252 [inline] validate_chain+0x18e0/0x5900 kernel/locking/lockdep.c:3868 __lock_acquire+0x137a/0x2040 kernel/locking/lockdep.c:5142 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5759 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd5/0x120 kernel/locking/spinlock.c:162 get_partial_node+0x36/0x280 mm/slub.c:2732 get_partial mm/slub.c:2846 [inline] ___slab_alloc+0xc17/0x14b0 mm/slub.c:3703 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_node_noprof+0x286/0x440 mm/slub.c:4164 kmalloc_node_noprof include/linux/slab.h:708 [inline] bpf_map_kmalloc_node+0xd3/0x1c0 kernel/bpf/syscall.c:422 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline] trie_update_elem+0x1cd/0xc00 kernel/bpf/lpm_trie.c:342 bpf_map_update_value+0x4d3/0x540 kernel/bpf/syscall.c:203 map_update_elem+0x53a/0x6f0 kernel/bpf/syscall.c:1654 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5698 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline] __se_sys_bpf kernel/bpf/syscall.c:5815 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5815 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fddac3799b9 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:00007fddad126038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fddac515f80 RCX: 00007fddac3799b9 RDX: 0000000000000020 RSI: 00000000200004c0 RDI: 0000000000000002 RBP: 00007fddac3e78d8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fddac515f80 R15: 00007ffc35cf3e38