syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.131-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.845/6775 is trying to acquire lock:
ffff88813fffacd8 (&zone->lock){..-.}-{2:2}, at: rmqueue_buddy mm/page_alloc.c:3724 [inline]
ffff88813fffacd8 (&zone->lock){..-.}-{2:2}, at: rmqueue mm/page_alloc.c:3877 [inline]
ffff88813fffacd8 (&zone->lock){..-.}-{2:2}, at: get_page_from_freelist+0xa9f/0x38d0 mm/page_alloc.c:4325

but task is already holding lock:
ffff8880587faa38 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc6/0xdc0 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}:
       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:467
       bpf_prog_04da3e87137f0056+0x26/0x3c
       bpf_dispatcher_nop_func include/linux/bpf.h:1000 [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:2284 [inline]
       bpf_trace_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2323
       trace_contention_end+0x14c/0x190 include/trace/events/lock.h:122
       __pv_queued_spin_lock_slowpath+0x935/0xc50 kernel/locking/qspinlock.c:560
       pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline]
       queued_spin_lock_slowpath+0x42/0x50 arch/x86/include/asm/qspinlock.h:51
       queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
       do_raw_spin_lock+0x269/0x370 kernel/locking/spinlock_debug.c:115
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
       _raw_spin_lock_irqsave+0xdd/0x120 kernel/locking/spinlock.c:162
       __free_pages_ok+0x622/0x1120 mm/page_alloc.c:1720
       free_large_kmalloc+0xfb/0x190 mm/slab_common.c:913
       skb_free_head net/core/skbuff.c:762 [inline]
       skb_release_data+0x5de/0x7a0 net/core/skbuff.c:791
       skb_release_all net/core/skbuff.c:856 [inline]
       __kfree_skb net/core/skbuff.c:870 [inline]
       kfree_skb_reason+0x16f/0x390 net/core/skbuff.c:893
       tipc_recvstream+0x807/0xf70 net/tipc/socket.c:2092
       ____sys_recvmsg+0x285/0x530
       ___sys_recvmsg net/socket.c:2780 [inline]
       __sys_recvmsg+0x2e9/0x3d0 net/socket.c:2810
       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

-> #0 (&zone->lock){..-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __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
       rmqueue_buddy mm/page_alloc.c:3724 [inline]
       rmqueue mm/page_alloc.c:3877 [inline]
       get_page_from_freelist+0xa9f/0x38d0 mm/page_alloc.c:4325
       __alloc_pages+0x28d/0x770 mm/page_alloc.c:5606
       __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:1077
       __do_kmalloc_node mm/slab_common.c:924 [inline]
       __kmalloc_node+0x111/0x230 mm/slab_common.c:943
       kmalloc_node include/linux/slab.h:589 [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+0x175/0xdc0 kernel/bpf/lpm_trie.c:338
       bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
       map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1463
       __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:5005
       __do_sys_bpf kernel/bpf/syscall.c:5121 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5119 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5119
       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

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.3.845/6775:
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e6c0 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x207/0x6f0 kernel/bpf/syscall.c:225
 #1: ffff8880587faa38 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc6/0xdc0 kernel/bpf/lpm_trie.c:335

stack backtrace:
CPU: 1 PID: 6775 Comm: syz.3.845 Not tainted 6.1.131-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __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
 rmqueue_buddy mm/page_alloc.c:3724 [inline]
 rmqueue mm/page_alloc.c:3877 [inline]
 get_page_from_freelist+0xa9f/0x38d0 mm/page_alloc.c:4325
 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5606
 __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:1077
 __do_kmalloc_node mm/slab_common.c:924 [inline]
 __kmalloc_node+0x111/0x230 mm/slab_common.c:943
 kmalloc_node include/linux/slab.h:589 [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+0x175/0xdc0 kernel/bpf/lpm_trie.c:338
 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
 map_update_elem+0x503/0x680 kernel/bpf/syscall.c:1463
 __sys_bpf+0x337/0x6c0 kernel/bpf/syscall.c:5005
 __do_sys_bpf kernel/bpf/syscall.c:5121 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5119 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5119
 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: 0033:0x7fdac498d169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdac5799038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdac4ba5fa0 RCX: 00007fdac498d169
RDX: 0000000000000020 RSI: 0000200000000000 RDI: 0000000000000002
RBP: 00007fdac4a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdac4ba5fa0 R15: 00007ffdad94d238
 </TASK>