syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.87-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.4/3858 is trying to acquire lock:
ffffffff91ebf728 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x68/0x4e0 lib/debugobjects.c:697

but task is already holding lock:
ffff888077b55a38 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:324

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:451
       0xffffffffa0002115
       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_run2+0x1fd/0x410 kernel/trace/bpf_trace.c:2312
       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
       debug_object_deactivate+0x63/0x380 lib/debugobjects.c:752
       debug_timer_deactivate kernel/time/timer.c:787 [inline]
       debug_deactivate kernel/time/timer.c:831 [inline]
       detach_timer+0x26/0x380 kernel/time/timer.c:878
       expire_timers kernel/time/timer.c:1538 [inline]
       __run_timers+0x60c/0x890 kernel/time/timer.c:1820
       run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
       __do_softirq+0x2e9/0xa4c kernel/softirq.c:571
       invoke_softirq kernel/softirq.c:445 [inline]
       __irq_exit_rcu+0x155/0x240 kernel/softirq.c:650
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:662
       sysvec_apic_timer_interrupt+0x91/0xb0 arch/x86/kernel/apic/apic.c:1106
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
       find_stack lib/stackdepot.c:304 [inline]
       __stack_depot_save+0x172/0x470 lib/stackdepot.c:452
       save_stack+0x104/0x1e0 mm/page_owner.c:128
       __set_page_owner+0x26/0x390 mm/page_owner.c:190
       set_page_owner include/linux/page_owner.h:31 [inline]
       post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2513
       prep_new_page mm/page_alloc.c:2520 [inline]
       get_page_from_freelist+0x31a1/0x3320 mm/page_alloc.c:4279
       __alloc_pages+0x28d/0x770 mm/page_alloc.c:5547
       __get_free_pages+0x8/0x30 mm/page_alloc.c:5597
       kasan_populate_vmalloc_pte+0x35/0xf0 mm/kasan/shadow.c:271
       apply_to_pte_range mm/memory.c:2645 [inline]
       apply_to_pmd_range mm/memory.c:2689 [inline]
       apply_to_pud_range mm/memory.c:2725 [inline]
       apply_to_p4d_range mm/memory.c:2761 [inline]
       __apply_to_page_range+0x9c5/0xcc0 mm/memory.c:2795
       alloc_vmap_area+0x1977/0x1ac0 mm/vmalloc.c:1646
       __get_vm_area_node+0x16c/0x360 mm/vmalloc.c:2505
       __vmalloc_node_range+0x394/0x1460 mm/vmalloc.c:3183
       alloc_thread_stack_node kernel/fork.c:311 [inline]
       dup_task_struct+0x3e5/0x6d0 kernel/fork.c:988
       copy_process+0x637/0x4060 kernel/fork.c:2098
       kernel_clone+0x222/0x920 kernel/fork.c:2682
       __do_sys_clone3 kernel/fork.c:2981 [inline]
       __se_sys_clone3+0x373/0x410 kernel/fork.c:2965
       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 (&obj_hash[i].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
       debug_object_activate+0x68/0x4e0 lib/debugobjects.c:697
       debug_rcu_head_queue kernel/rcu/rcu.h:189 [inline]
       kvfree_call_rcu+0xb4/0x8c0 kernel/rcu/tree.c:3391
       trie_update_elem+0x808/0xc00 kernel/bpf/lpm_trie.c:385
       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

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&obj_hash[i].lock);
                               lock(&trie->lock);
  lock(&obj_hash[i].lock);

 *** DEADLOCK ***

2 locks held by syz-executor.4/3858:
 #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: ffff888077b55a38 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc5/0xc00 kernel/bpf/lpm_trie.c:324

stack backtrace:
CPU: 0 PID: 3858 Comm: syz-executor.4 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
 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
 debug_object_activate+0x68/0x4e0 lib/debugobjects.c:697
 debug_rcu_head_queue kernel/rcu/rcu.h:189 [inline]
 kvfree_call_rcu+0xb4/0x8c0 kernel/rcu/tree.c:3391
 trie_update_elem+0x808/0xc00 kernel/bpf/lpm_trie.c:385
 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: 0033:0x7f2a3767dea9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2a383e80c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f2a377abf80 RCX: 00007f2a3767dea9
RDX: 0000000000000020 RSI: 0000000020000380 RDI: 0000000000000002
RBP: 00007f2a376ca4a4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2a377abf80 R15: 00007fffb6e8d688
 </TASK>