syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.129-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.1949/10106 is trying to acquire lock:
ffffffff97699b10 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:968 [inline]
ffffffff97699b10 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0xd8/0x4e0 lib/debugobjects.c:1009

but task is already holding lock:
ffff88807d830a38 (&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
       0xffffffffa0001e96
       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
       debug_object_deactivate+0x63/0x380 lib/debugobjects.c:753
       debug_hrtimer_deactivate kernel/time/hrtimer.c:426 [inline]
       debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:482
       __run_hrtimer kernel/time/hrtimer.c:1657 [inline]
       __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1753
       hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1815
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
       __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
       sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1118
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
       note_gp_changes+0x2ba/0x350 kernel/rcu/tree.c:1323
       rcu_check_quiescent_state kernel/rcu/tree.c:2121 [inline]
       rcu_core+0x2c9/0x1820 kernel/rcu/tree.c:2541
       handle_softirqs+0x2ee/0xa40 kernel/softirq.c:578
       __do_softirq kernel/softirq.c:612 [inline]
       invoke_softirq kernel/softirq.c:452 [inline]
       __irq_exit_rcu+0x157/0x240 kernel/softirq.c:661
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:673
       instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
       sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
       asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
       lock_mm_and_find_vma+0x0/0x2e0
       do_user_addr_fault arch/x86/mm/fault.c:1312 [inline]
       handle_page_fault arch/x86/mm/fault.c:1431 [inline]
       exc_page_fault+0x169/0x620 arch/x86/mm/fault.c:1487
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
       copy_user_enhanced_fast_string+0xa/0x40 arch/x86/lib/copy_user_64.S:165
       copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
       raw_copy_to_user arch/x86/include/asm/uaccess_64.h:58 [inline]
       copyout+0xd8/0x120 lib/iov_iter.c:170
       _copy_to_iter+0x4a6/0x1000 lib/iov_iter.c:527
       __skb_datagram_iter+0xdd/0x7c0 net/core/datagram.c:419
       skb_copy_datagram_iter+0xe1/0x2b0 net/core/datagram.c:535
       skb_copy_datagram_msg include/linux/skbuff.h:3956 [inline]
       tipc_recvstream+0x7a4/0xf70 net/tipc/socket.c:2071
       ____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 (&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_check_no_obj_freed lib/debugobjects.c:968 [inline]
       debug_check_no_obj_freed+0xd8/0x4e0 lib/debugobjects.c:1009
       slab_free_hook mm/slub.c:1699 [inline]
       slab_free_freelist_hook mm/slub.c:1750 [inline]
       slab_free mm/slub.c:3661 [inline]
       __kmem_cache_free+0x205/0x3c0 mm/slub.c:3674
       trie_update_elem+0x790/0xdc0 kernel/bpf/lpm_trie.c:444
       bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
       generic_map_update_batch+0x579/0x920 kernel/bpf/syscall.c:1699
       bpf_map_do_batch+0x4d0/0x620
       __sys_bpf+0x658/0x6c0
       __do_sys_bpf kernel/bpf/syscall.c:5129 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5127 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5127
       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.2.1949/10106:
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #0: ffffffff8d32e680 (rcu_read_lock){....}-{1:2}, at: bpf_map_update_value+0x207/0x6f0 kernel/bpf/syscall.c:225
 #1: ffff88807d830a38 (&trie->lock){-.-.}-{2:2}, at: trie_update_elem+0xc6/0xdc0 kernel/bpf/lpm_trie.c:335

stack backtrace:
CPU: 1 PID: 10106 Comm: syz.2.1949 Not tainted 6.1.129-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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_check_no_obj_freed lib/debugobjects.c:968 [inline]
 debug_check_no_obj_freed+0xd8/0x4e0 lib/debugobjects.c:1009
 slab_free_hook mm/slub.c:1699 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0x205/0x3c0 mm/slub.c:3674
 trie_update_elem+0x790/0xdc0 kernel/bpf/lpm_trie.c:444
 bpf_map_update_value+0x5cf/0x6f0 kernel/bpf/syscall.c:226
 generic_map_update_batch+0x579/0x920 kernel/bpf/syscall.c:1699
 bpf_map_do_batch+0x4d0/0x620
 __sys_bpf+0x658/0x6c0
 __do_sys_bpf kernel/bpf/syscall.c:5129 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5127 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5127
 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: 0033:0x7fe3e2d8d169
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:00007fe3e3c46038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fe3e2fa5fa0 RCX: 00007fe3e2d8d169
RDX: 0000000000000038 RSI: 0000400000000240 RDI: 000000000000001a
RBP: 00007fe3e2e0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe3e2fa5fa0 R15: 00007ffc2381e988
 </TASK>