======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.3.159/6230 is trying to acquire lock:
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: rmqueue_buddy mm/page_alloc.c:2697 [inline]
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: rmqueue mm/page_alloc.c:2837 [inline]
ffff88813fffacd8 (&zone->lock){-.-.}-{2:2}, at: get_page_from_freelist+0x892/0x22a0 mm/page_alloc.c:3218

but task is already holding lock:
ffff88807dabe238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc4/0xd60 kernel/bpf/lpm_trie.c:335

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&trie->lock){-.-.}-{2:2}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466
       0xffffffffa0000a5a
       bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
       __bpf_prog_run include/linux/filter.h:617 [inline]
       bpf_prog_run include/linux/filter.h:624 [inline]
       bpf_prog_run_array include/linux/bpf.h:1994 [inline]
       trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
       perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10295
       perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
       trace_lock_acquire include/trace/events/lock.h:24 [inline]
       lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5727
       seqcount_lockdep_reader_access+0xbc/0x190 include/linux/seqlock.h:102
       read_seqbegin include/linux/seqlock.h:893 [inline]
       zone_span_seqbegin include/linux/memory_hotplug.h:134 [inline]
       page_outside_zone_boundaries mm/page_alloc.c:475 [inline]
       bad_range+0x61/0x280 mm/page_alloc.c:494
       expand+0x76/0x2b0 mm/page_alloc.c:1443
       __rmqueue_smallest mm/page_alloc.c:1625 [inline]
       __rmqueue mm/page_alloc.c:2151 [inline]
       rmqueue_bulk mm/page_alloc.c:2177 [inline]
       __rmqueue_pcplist+0xf27/0x1580 mm/page_alloc.c:2752
       rmqueue_pcplist mm/page_alloc.c:2794 [inline]
       rmqueue mm/page_alloc.c:2831 [inline]
       get_page_from_freelist+0x670/0x22a0 mm/page_alloc.c:3218
       __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
       alloc_slab_page+0x5d/0x180 mm/slub.c:1881
       allocate_slab mm/slub.c:2028 [inline]
       new_slab+0x87/0x2d0 mm/slub.c:2081
       ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253
       __slab_alloc mm/slub.c:3339 [inline]
       __slab_alloc_node mm/slub.c:3392 [inline]
       slab_alloc_node mm/slub.c:3485 [inline]
       __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534
       __do_kmalloc_node mm/slab_common.c:1006 [inline]
       __kmalloc_node_track_caller+0xa4/0x230 mm/slab_common.c:1027
       kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584
       __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653
       alloc_skb include/linux/skbuff.h:1316 [inline]
       nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
       nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
       nsim_dev_trap_report_work+0x253/0xa90 drivers/net/netdevsim/dev.c:851
       process_one_work kernel/workqueue.c:2657 [inline]
       process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734
       worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815
       kthread+0x2fa/0x390 kernel/kthread.c:388
       ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
       ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293

-> #0 (&zone->lock){-.-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
       lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
       rmqueue_buddy mm/page_alloc.c:2697 [inline]
       rmqueue mm/page_alloc.c:2837 [inline]
       get_page_from_freelist+0x892/0x22a0 mm/page_alloc.c:3218
       __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
       __alloc_pages_node include/linux/gfp.h:237 [inline]
       alloc_pages_node include/linux/gfp.h:260 [inline]
       __kmalloc_large_node+0x8c/0x1f0 mm/slab_common.c:1148
       __do_kmalloc_node mm/slab_common.c:995 [inline]
       __kmalloc_node+0x112/0x240 mm/slab_common.c:1014
       kmalloc_node include/linux/slab.h:620 [inline]
       bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:424
       lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
       trie_update_elem+0x172/0xd60 kernel/bpf/lpm_trie.c:338
       bpf_map_update_value+0x64b/0x710 kernel/bpf/syscall.c:203
       map_update_elem+0x586/0x710 kernel/bpf/syscall.c:1567
       __sys_bpf+0x6b5/0x890 kernel/bpf/syscall.c:5479
       __do_sys_bpf kernel/bpf/syscall.c:5595 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5593 [inline]
       __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5593
       do_syscall_x64 arch/x86/entry/common.c:46 [inline]
       do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&zone->lock);
                               lock(&trie->lock);
  lock(&zone->lock);

 *** DEADLOCK ***

2 locks held by syz.3.159/6230:
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
 #0: ffffffff8d1320e0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x408/0x710 kernel/bpf/syscall.c:202
 #1: ffff88807dabe238 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc4/0xd60 kernel/bpf/lpm_trie.c:335

stack backtrace:
CPU: 0 PID: 6230 Comm: syz.3.159 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
 check_noncircular+0x2fc/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
 lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5756
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
 rmqueue_buddy mm/page_alloc.c:2697 [inline]
 rmqueue mm/page_alloc.c:2837 [inline]
 get_page_from_freelist+0x892/0x22a0 mm/page_alloc.c:3218
 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501
 __alloc_pages_node include/linux/gfp.h:237 [inline]
 alloc_pages_node include/linux/gfp.h:260 [inline]
 __kmalloc_large_node+0x8c/0x1f0 mm/slab_common.c:1148
 __do_kmalloc_node mm/slab_common.c:995 [inline]
 __kmalloc_node+0x112/0x240 mm/slab_common.c:1014
 kmalloc_node include/linux/slab.h:620 [inline]
 bpf_map_kmalloc_node+0xbc/0x1b0 kernel/bpf/syscall.c:424
 lpm_trie_node_alloc kernel/bpf/lpm_trie.c:291 [inline]
 trie_update_elem+0x172/0xd60 kernel/bpf/lpm_trie.c:338
 bpf_map_update_value+0x64b/0x710 kernel/bpf/syscall.c:203
 map_update_elem+0x586/0x710 kernel/bpf/syscall.c:1567
 __sys_bpf+0x6b5/0x890 kernel/bpf/syscall.c:5479
 __do_sys_bpf kernel/bpf/syscall.c:5595 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5593 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5593
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f26f939e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f26fa211028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f26f9625fa0 RCX: 00007f26f939e159
RDX: 0000000000000020 RSI: 0000200000000080 RDI: 0000000000000002
RBP: 00007f26f943506b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f26f9626038 R14: 00007f26f9625fa0 R15: 00007ffca5786f28
 </TASK>