syzbot

============================================
WARNING: possible recursive locking detected
6.12.0-syzkaller-00971-g158f238aa69d #0 Not tainted
--------------------------------------------
syz-executor701/5842 is trying to acquire lock:
ffff888028877200 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x96/0x6a0 kernel/bpf/lpm_trie.c:462

but task is already holding lock:
ffff888028870200 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333

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-executor701/5842:
 #0: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #0: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #0: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x3c4/0x540 kernel/bpf/syscall.c:202
 #1: ffff888028870200 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc8/0xc00 kernel/bpf/lpm_trie.c:333
 #2: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
 #2: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
 #2: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2315 [inline]
 #2: ffffffff8e939f60 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x244/0x590 kernel/trace/bpf_trace.c:2359

stack backtrace:
CPU: 1 UID: 0 PID: 5842 Comm: syz-executor701 Not tainted 6.12.0-syzkaller-00971-g158f238aa69d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_deadlock_bug+0x483/0x620 kernel/locking/lockdep.c:3037
 check_deadlock kernel/locking/lockdep.c:3089 [inline]
 validate_chain+0x15e2/0x5920 kernel/locking/lockdep.c:3891
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825
 __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
 bpf_prog_8c8ab8634bca3061+0x43/0x51
 bpf_dispatcher_nop_func include/linux/bpf.h:1265 [inline]
 __bpf_prog_run include/linux/filter.h:701 [inline]
 bpf_prog_run include/linux/filter.h:708 [inline]
 __bpf_trace_run kernel/trace/bpf_trace.c:2316 [inline]
 bpf_trace_run4+0x336/0x590 kernel/trace/bpf_trace.c:2359
 trace_mm_page_alloc include/trace/events/kmem.h:177 [inline]
 __alloc_pages_noprof+0x6dc/0x710 mm/page_alloc.c:4773
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 ___kmalloc_large_node+0x8b/0x1d0 mm/slub.c:4209
 __kmalloc_large_node_noprof+0x1a/0x80 mm/slub.c:4236
 __do_kmalloc_node mm/slub.c:4252 [inline]
 __kmalloc_node_noprof+0x2d2/0x440 mm/slub.c:4270
 kmalloc_node_noprof include/linux/slab.h:905 [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+0x4d5/0x540 kernel/bpf/syscall.c:203
 map_update_elem+0x51a/0x6f0 kernel/bpf/syscall.c:1626
 __sys_bpf+0x76f/0x810 kernel/bpf/syscall.c:5641
 __do_sys_bpf kernel/bpf/syscall.c:5760 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5758 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5758
 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: 0033:0x7f82c4efada9
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:00007fff29303878 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82c4efada9
RDX: 0000000000000020 RSI: 0000000020000000 RDI: 0000000000000002
RBP: 00000000000f4240 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 00007fff29303a98 R14: 00007fff293038a0 R15: 00007fff29303890
 </TASK>