syzbot

============================================
WARNING: possible recursive locking detected
6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0 Not tainted
--------------------------------------------
syz-executor120/5234 is trying to acquire lock:
ffff88802dd119f8 (&trie->lock){..-.}-{2:2}, at: trie_delete_elem+0xb0/0x820 kernel/bpf/lpm_trie.c:462

but task is already holding lock:
ffff88802dd171f8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xe00 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-executor120/5234:
 #0: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #0: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #0: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x24b/0x6c0 kernel/bpf/syscall.c:202
 #1: ffff88802dd171f8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xc8/0xe00 kernel/bpf/lpm_trie.c:333
 #2: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 #2: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline]
 #2: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2405 [inline]
 #2: ffffffff8ddb5ce0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run4+0x1d6/0x5a0 kernel/trace/bpf_trace.c:2449

stack backtrace:
CPU: 0 UID: 0 PID: 5234 Comm: syz-executor120 Not tainted 6.11.0-rc3-syzkaller-00013-g6b0f8db921ab #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 check_deadlock kernel/locking/lockdep.c:3061 [inline]
 validate_chain kernel/locking/lockdep.c:3855 [inline]
 __lock_acquire+0x2167/0x3cb0 kernel/locking/lockdep.c:5142
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 trie_delete_elem+0xb0/0x820 kernel/bpf/lpm_trie.c:462
 ___bpf_prog_run+0x3e51/0xabd0 kernel/bpf/core.c:2010
 __bpf_prog_run32+0xc1/0x100 kernel/bpf/core.c:2251
 bpf_dispatcher_nop_func include/linux/bpf.h:1243 [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:2406 [inline]
 bpf_trace_run4+0x245/0x5a0 kernel/trace/bpf_trace.c:2449
 trace_mm_page_alloc include/trace/events/kmem.h:177 [inline]
 __alloc_pages_noprof+0x3ad/0x2460 mm/page_alloc.c:4722
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 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+0x357/0x430 mm/slub.c:4164
 kmalloc_node_noprof include/linux/slab.h:708 [inline]
 bpf_map_kmalloc_node+0x98/0x4a0 kernel/bpf/syscall.c:422
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:299 [inline]
 trie_update_elem+0x1ef/0xe00 kernel/bpf/lpm_trie.c:342
 bpf_map_update_value+0x2c1/0x6c0 kernel/bpf/syscall.c:203
 generic_map_update_batch+0x454/0x5f0 kernel/bpf/syscall.c:1889
 bpf_map_do_batch+0x64a/0x720 kernel/bpf/syscall.c:5218
 __sys_bpf+0x19a9/0x4a20 kernel/bpf/syscall.c:5774
 __do_sys_bpf kernel/bpf/syscall.c:5817 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5815 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5815
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5827061de9
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:00007fff4f6d28c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5827061de9
RDX: 0000000000000038 RSI: 0000000020000240 RDI: 000000000000001a
RBP: 0000000000000000 R08: 00000000000000a0 R09: 00000000000000a0
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>