syzbot

============================================
WARNING: possible recursive locking detected
6.1.87-syzkaller #0 Not tainted
--------------------------------------------
syz-executor205/3556 is trying to acquire lock:
ffff88807e521a38 (&trie->lock){....}-{2:2}, at: trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451

but task is already holding lock:
ffff88807e522238 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:324

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-executor205/3556:
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x207/0x6f0 kernel/bpf/syscall.c:225
 #1: ffff88807e522238 (&trie->lock){....}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:324
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2272 [inline]
 #2: ffffffff8d12ac80 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x16a/0x470 kernel/trace/bpf_trace.c:2314

stack backtrace:
CPU: 1 PID: 3556 Comm: syz-executor205 Not tainted 6.1.87-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __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:2983 [inline]
 check_deadlock kernel/locking/lockdep.c:3026 [inline]
 validate_chain+0x4711/0x5950 kernel/locking/lockdep.c:3812
 __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
 trie_delete_elem+0x90/0x690 kernel/bpf/lpm_trie.c:451
 bpf_prog_1db1603a7cfa36fb+0x3d/0x41
 bpf_dispatcher_nop_func include/linux/bpf.h:989 [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:2273 [inline]
 bpf_trace_run4+0x253/0x470 kernel/trace/bpf_trace.c:2314
 __bpf_trace_mm_page_alloc+0xba/0xe0 include/trace/events/kmem.h:177
 __traceiter_mm_page_alloc+0x35/0x50 include/trace/events/kmem.h:177
 trace_mm_page_alloc include/trace/events/kmem.h:177 [inline]
 __alloc_pages+0x717/0x770 mm/page_alloc.c:5569
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x91/0x1d0 mm/slab_common.c:1096
 __do_kmalloc_node mm/slab_common.c:943 [inline]
 __kmalloc_node+0x111/0x230 mm/slab_common.c:962
 kmalloc_node include/linux/slab.h:582 [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+0x1cb/0xc00 kernel/bpf/lpm_trie.c:333
 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1448
 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:4993
 __do_sys_bpf kernel/bpf/syscall.c:5109 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5107 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5107
 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: 0033:0x7fe602b40fa9
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:00007ffdbe9b1568 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fe602b40fa9
RDX: 0000000000000020 RSI: 0000000020000080 RDI: 0000000000000002
RBP: 0000000000000000 R08: 00000000000000a0 R09: 00000000000000a0
R10: 00000000000000a0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>