============================================ WARNING: possible recursive locking detected 5.15.152-syzkaller #0 Not tainted -------------------------------------------- syz-executor216/3554 is trying to acquire lock: ffff88802362bdb8 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:450 but task is already holding lock: ffff88802362bdb8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:323 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&trie->lock); lock(&trie->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by syz-executor216/3554: #0: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 #1: ffff88802362bdb8 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:323 #2: ffffffff8c91f720 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:268 stack backtrace: CPU: 0 PID: 3554 Comm: syz-executor216 Not tainted 5.15.152-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106 print_deadlock_bug kernel/locking/lockdep.c:2946 [inline] check_deadlock kernel/locking/lockdep.c:2989 [inline] validate_chain+0x46d2/0x5930 kernel/locking/lockdep.c:3775 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623 __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:450 bpf_prog_fdee3c9a1e8a2a6e+0x3d/0x99c bpf_dispatcher_nop_func include/linux/bpf.h:780 [inline] __bpf_prog_run include/linux/filter.h:625 [inline] bpf_prog_run include/linux/filter.h:632 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1880 [inline] bpf_trace_run4+0x1ea/0x390 kernel/trace/bpf_trace.c:1919 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:201 trace_mm_page_alloc include/trace/events/kmem.h:201 [inline] __alloc_pages+0x6e0/0x700 mm/page_alloc.c:5443 stack_depot_save+0x319/0x440 lib/stackdepot.c:302 save_stack+0x104/0x1e0 mm/page_owner.c:120 __set_page_owner+0x37/0x300 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x322a/0x33c0 mm/page_alloc.c:4159 __alloc_pages+0x272/0x700 mm/page_alloc.c:5421 __alloc_pages_node include/linux/gfp.h:570 [inline] alloc_slab_page mm/slub.c:1777 [inline] allocate_slab mm/slub.c:1912 [inline] new_slab+0xb1/0x4b0 mm/slub.c:1975 ___slab_alloc+0x6f6/0xe10 mm/slub.c:3008 __slab_alloc mm/slub.c:3095 [inline] slab_alloc_node mm/slub.c:3186 [inline] __kmalloc_node+0x1fa/0x390 mm/slub.c:4451 kmalloc_node include/linux/slab.h:614 [inline] bpf_map_kmalloc_node+0xdb/0x160 kernel/bpf/syscall.c:430 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:290 [inline] trie_update_elem+0x1cb/0xc00 kernel/bpf/lpm_trie.c:332 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221 map_update_elem+0x6a0/0x7c0 kernel/bpf/syscall.c:1163 __sys_bpf+0x2fd/0x670 kernel/bpf/syscall.c:4617 __do_sys_bpf kernel/bpf/syscall.c:4733 [inline] __se_sys_bpf kernel/bpf/syscall.c:4731 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4731 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7ff46a416df9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 c1 17 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffda9355f78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff46a416df9 RDX: 0000000000000020 RSI: 0000000020000300 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000006 R09: 0000000000000006 R10: 0000000000000006 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000001