======================================================
WARNING: possible circular locking dependency detected
5.15.175-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.107/4570 is trying to acquire lock:
ffff8880b8f27e78 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline]
ffff8880b8f27e78 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline]
ffff8880b8f27e78 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597

but task is already holding lock:
ffff88802bc355b8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xcf/0xca0 kernel/bpf/lpm_trie.c:323

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&trie->lock){..-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __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
       0xffffffffa001a33e
       bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline]
       __bpf_prog_run include/linux/filter.h:628 [inline]
       bpf_prog_run include/linux/filter.h:635 [inline]
       __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline]
       bpf_trace_run3+0x1d1/0x380 kernel/trace/bpf_trace.c:1916
       trace_timer_start include/trace/events/timer.h:52 [inline]
       enqueue_timer+0x3ae/0x540 kernel/time/timer.c:586
       internal_add_timer kernel/time/timer.c:611 [inline]
       __mod_timer+0xa60/0xeb0 kernel/time/timer.c:1062
       sk_reset_timer+0x1f/0xb0 net/core/sock.c:3136
       tipc_sk_finish_conn+0x162/0x810 net/tipc/socket.c:1675
       tipc_socketpair+0x253/0x4a0 net/tipc/socket.c:3348
       __sys_socketpair+0x402/0x700 net/socket.c:1659
       __do_sys_socketpair net/socket.c:1695 [inline]
       __se_sys_socketpair net/socket.c:1692 [inline]
       __x64_sys_socketpair+0x97/0xb0 net/socket.c:1692
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

-> #1 (&base->lock){-.-.}-{2:2}:
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
       lock_timer_base+0x120/0x260 kernel/time/timer.c:946
       __mod_timer+0x1d6/0xeb0 kernel/time/timer.c:1019
       queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1715
       queue_delayed_work include/linux/workqueue.h:527 [inline]
       schedule_delayed_work include/linux/workqueue.h:631 [inline]
       kvfree_call_rcu+0x50e/0x8a0 kernel/rcu/tree.c:3625
       rtnl_register_internal+0x443/0x530 net/core/rtnetlink.c:223
       rtnl_register+0x32/0x70 net/core/rtnetlink.c:273
       ip_rt_init+0x2e6/0x390 net/ipv4/route.c:3750
       ip_init+0xa/0x20 net/ipv4/ip_output.c:1749
       inet_init+0x27c/0x390 net/ipv4/af_inet.c:2007
       do_one_initcall+0x22b/0x7a0 init/main.c:1302
       do_initcall_level+0x157/0x210 init/main.c:1375
       do_initcalls+0x49/0x90 init/main.c:1391
       kernel_init_freeable+0x425/0x5c0 init/main.c:1615
       kernel_init+0x19/0x290 init/main.c:1506
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

-> #0 (krc.lock){..-.}-{2:2}:
       check_prev_add kernel/locking/lockdep.c:3053 [inline]
       check_prevs_add kernel/locking/lockdep.c:3172 [inline]
       validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
       __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
       lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
       __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline]
       add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline]
       kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597
       trie_update_elem+0x8ad/0xca0 kernel/bpf/lpm_trie.c:396
       bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221
       generic_map_update_batch+0x54d/0x8b0 kernel/bpf/syscall.c:1421
       bpf_map_do_batch+0x4d0/0x620
       __sys_bpf+0x55c/0x670
       __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x66/0xd0

other info that might help us debug this:

Chain exists of:
  krc.lock --> &base->lock --> &trie->lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&trie->lock);
                               lock(&base->lock);
                               lock(&trie->lock);
  lock(krc.lock);

 *** DEADLOCK ***

2 locks held by syz.4.107/4570:
 #0: ffffffff8cb1fd20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
 #1: ffff88802bc355b8 (&trie->lock){..-.}-{2:2}, at: trie_update_elem+0xcf/0xca0 kernel/bpf/lpm_trie.c:323

stack backtrace:
CPU: 1 PID: 4570 Comm: syz.4.107 Not tainted 5.15.175-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
 check_prev_add kernel/locking/lockdep.c:3053 [inline]
 check_prevs_add kernel/locking/lockdep.c:3172 [inline]
 validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
 __lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
 lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 krc_this_cpu_lock kernel/rcu/tree.c:3199 [inline]
 add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3506 [inline]
 kvfree_call_rcu+0x1b5/0x8a0 kernel/rcu/tree.c:3597
 trie_update_elem+0x8ad/0xca0 kernel/bpf/lpm_trie.c:396
 bpf_map_update_value+0x5d7/0x6c0 kernel/bpf/syscall.c:221
 generic_map_update_batch+0x54d/0x8b0 kernel/bpf/syscall.c:1421
 bpf_map_do_batch+0x4d0/0x620
 __sys_bpf+0x55c/0x670
 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4753 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc595d91d29
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:00007fc593c02038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fc595f81fa0 RCX: 00007fc595d91d29
RDX: 0000000000000038 RSI: 0000000020000240 RDI: 000000000000001a
RBP: 00007fc595e0daa8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc595f81fa0 R15: 00007ffc14871b48
 </TASK>