======================================================
WARNING: possible circular locking dependency detected
6.1.132-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.1319/8434 is trying to acquire lock:
ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline]
ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline]
ffff8880b8f28118 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402

but task is already holding lock:
ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&base->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
       lock_timer_base+0x120/0x260 kernel/time/timer.c:999
       __mod_timer+0x1cb/0xee0 kernel/time/timer.c:1072
       queue_delayed_work_on+0x156/0x250 kernel/workqueue.c:1704
       queue_delayed_work include/linux/workqueue.h:527 [inline]
       schedule_delayed_monitor_work kernel/rcu/tree.c:3172 [inline]
       kvfree_call_rcu+0x520/0x8c0 kernel/rcu/tree.c:3428
       rtnl_register_internal+0x489/0x580 net/core/rtnetlink.c:260
       rtnl_register+0x32/0x70 net/core/rtnetlink.c:310
       ip_rt_init+0x335/0x3c7 net/ipv4/route.c:3789
       ip_init+0xa/0x14 net/ipv4/ip_output.c:1770
       inet_init+0x2ae/0x3c0 net/ipv4/af_inet.c:2033
       do_one_initcall+0x265/0x8f0 init/main.c:1298
       do_initcall_level+0x157/0x207 init/main.c:1371
       do_initcalls+0x49/0x86 init/main.c:1387
       kernel_init_freeable+0x45c/0x60f init/main.c:1626
       kernel_init+0x19/0x290 init/main.c:1514
       ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

-> #0 (krc.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 include/linux/spinlock_api_smp.h:133 [inline]
       _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
       krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline]
       add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline]
       kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402
       trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545
       bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e
       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_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324
       trace_timer_start include/trace/events/timer.h:53 [inline]
       enqueue_timer+0x440/0x600 kernel/time/timer.c:609
       __mod_timer+0x92b/0xee0 kernel/time/timer.c:-1
       dsp_cmx_send+0x21d7/0x2270 drivers/isdn/mISDN/dsp_cmx.c:1850
       call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
       expire_timers kernel/time/timer.c:1549 [inline]
       __run_timers+0x67c/0x890 kernel/time/timer.c:1820
       run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
       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_is_held_type+0x137/0x180 arch/x86/include/asm/irqflags.h:-1
       lock_is_held include/linux/lockdep.h:283 [inline]
       __might_resched+0xf0/0x780 kernel/sched/core.c:9928
       might_alloc include/linux/sched/mm.h:274 [inline]
       slab_pre_alloc_hook+0x4a/0x300 mm/slab.h:710
       slab_alloc_node mm/slub.c:3318 [inline]
       slab_alloc mm/slub.c:3406 [inline]
       __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
       kmem_cache_alloc+0x4e/0x2d0 mm/slub.c:3422
       sk_prot_alloc+0x58/0x200 net/core/sock.c:2044
       sk_alloc+0x36/0x350 net/core/sock.c:2103
       tipc_sk_create+0x107/0x2030 net/tipc/socket.c:488
       __sock_create+0x488/0x930 net/socket.c:1550
       sock_create net/socket.c:1606 [inline]
       __sys_socketpair+0x2c1/0x700 net/socket.c:1733
       __do_sys_socketpair net/socket.c:1786 [inline]
       __se_sys_socketpair net/socket.c:1783 [inline]
       __x64_sys_socketpair+0x97/0xb0 net/socket.c:1783
       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(&base->lock);
                               lock(krc.lock);
                               lock(&base->lock);
  lock(krc.lock);

 *** DEADLOCK ***

4 locks held by syz.2.1319/8434:
 #0: ffffc900001e0bc0 ((&dsp_spl_tl)){+.-.}-{0:0}, at: call_timer_fn+0xc2/0x6b0 kernel/time/timer.c:1501
 #1: ffffffff8e2e2018 (dsp_lock){..-.}-{2:2}, at: dsp_cmx_send+0x22/0x2270 drivers/isdn/mISDN/dsp_cmx.c:1643
 #2: ffff8880b8f28358 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x120/0x260 kernel/time/timer.c:999
 #3: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2283 [inline]
 #3: ffffffff8d32e740 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0x146/0x440 kernel/trace/bpf_trace.c:2324

stack backtrace:
CPU: 1 PID: 8434 Comm: syz.2.1319 Not tainted 6.1.132-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __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 include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline]
 add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline]
 kvfree_call_rcu+0x1b2/0x8c0 kernel/rcu/tree.c:3402
 trie_delete_elem+0x53a/0x690 kernel/bpf/lpm_trie.c:545
 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e
 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_run3+0x231/0x440 kernel/trace/bpf_trace.c:2324
 trace_timer_start include/trace/events/timer.h:53 [inline]
 enqueue_timer+0x440/0x600 kernel/time/timer.c:609
 __mod_timer+0x92b/0xee0 kernel/time/timer.c:-1
 dsp_cmx_send+0x21d7/0x2270 drivers/isdn/mISDN/dsp_cmx.c:1850
 call_timer_fn+0x1ad/0x6b0 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x67c/0x890 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:lock_is_held_type+0x137/0x180 arch/x86/include/asm/irqflags.h:-1
Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000358f9b8 EFLAGS: 00000206
RAX: a501aa0f290de800 RBX: 0000000000000000 RCX: ffff88802fb7bb80
RDX: 0000000000000000 RSI: ffffffff8b0c2f40 RDI: ffffffff8b5f70e0
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffffbfff1d416c6
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000246
R13: ffff88802fb7bb80 R14: 00000000ffffffff R15: ffffffff8d32e6c0
 lock_is_held include/linux/lockdep.h:283 [inline]
 __might_resched+0xf0/0x780 kernel/sched/core.c:9928
 might_alloc include/linux/sched/mm.h:274 [inline]
 slab_pre_alloc_hook+0x4a/0x300 mm/slab.h:710
 slab_alloc_node mm/slub.c:3318 [inline]
 slab_alloc mm/slub.c:3406 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3413 [inline]
 kmem_cache_alloc+0x4e/0x2d0 mm/slub.c:3422
 sk_prot_alloc+0x58/0x200 net/core/sock.c:2044
 sk_alloc+0x36/0x350 net/core/sock.c:2103
 tipc_sk_create+0x107/0x2030 net/tipc/socket.c:488
 __sock_create+0x488/0x930 net/socket.c:1550
 sock_create net/socket.c:1606 [inline]
 __sys_socketpair+0x2c1/0x700 net/socket.c:1733
 __do_sys_socketpair net/socket.c:1786 [inline]
 __se_sys_socketpair net/socket.c:1783 [inline]
 __x64_sys_socketpair+0x97/0xb0 net/socket.c:1783
 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: 0033:0x7fad8798d169
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:00007fad887cc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000035
RAX: ffffffffffffffda RBX: 00007fad87ba5fa0 RCX: 00007fad8798d169
RDX: 0000000000000000 RSI: 0000000000000005 RDI: 000000000000001e
RBP: 00007fad87a0e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000940 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fad87ba5fa0 R15: 00007ffd5d2d4428
 </TASK>
----------------
Code disassembly (best guess):
   0:	75 40                	jne    0x42
   2:	48 c7 04 24 00 00 00 	movq   $0x0,(%rsp)
   9:	00
   a:	9c                   	pushf
   b:	8f 04 24             	pop    (%rsp)
   e:	f7 04 24 00 02 00 00 	testl  $0x200,(%rsp)
  15:	75 46                	jne    0x5d
  17:	41 f7 c4 00 02 00 00 	test   $0x200,%r12d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  28:	00 00
* 2a:	48 3b 44 24 08       	cmp    0x8(%rsp),%rax <-- trapping instruction
  2f:	75 3c                	jne    0x6d
  31:	89 e8                	mov    %ebp,%eax
  33:	48 83 c4 10          	add    $0x10,%rsp
  37:	5b                   	pop    %rbx
  38:	41 5c                	pop    %r12
  3a:	41 5d                	pop    %r13
  3c:	41 5e                	pop    %r14
  3e:	41 5f                	pop    %r15