======================================================
WARNING: possible circular locking dependency detected
6.1.141-syzkaller #0 Not tainted
------------------------------------------------------
syz.2.2323/13915 is trying to acquire lock:
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline]
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline]
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402

but task is already holding lock:
ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 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}:
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
       lock_timer_base+0x123/0x270 kernel/time/timer.c:999
       __mod_timer+0x117/0xd20 kernel/time/timer.c:1072
       queue_delayed_work_on+0x126/0x1e0 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+0x4cb/0x870 kernel/rcu/tree.c:3428
       rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:260
       rtnl_register+0x2e/0x70 net/core/rtnetlink.c:310
       ip_rt_init+0x323/0x3b5 net/ipv4/route.c:3789
       ip_init+0xa/0x14 net/ipv4/ip_output.c:1771
       inet_init+0x2bd/0x3cf net/ipv4/af_inet.c:2033
       do_one_initcall+0x214/0x7a0 init/main.c:1298
       do_initcall_level+0x137/0x1e4 init/main.c:1371
       do_initcalls+0x4b/0x8a init/main.c:1387
       kernel_init_freeable+0x3fa/0x5ac init/main.c:1626
       kernel_init+0x19/0x1b0 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 kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 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+0x184/0x870 kernel/rcu/tree.c:3402
       trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
       bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e
       bpf_dispatcher_nop_func include/linux/bpf.h:1001 [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:2285 [inline]
       bpf_trace_run3+0x1e3/0x400 kernel/trace/bpf_trace.c:2325
       trace_timer_start include/trace/events/timer.h:53 [inline]
       enqueue_timer+0x411/0x5c0 kernel/time/timer.c:609
       internal_add_timer kernel/time/timer.c:634 [inline]
       __mod_timer+0x8e1/0xd20 kernel/time/timer.c:1115
       mrp_join_timer_arm net/802/mrp.c:596 [inline]
       mrp_join_timer+0x13b/0x170 net/802/mrp.c:611
       call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
       expire_timers kernel/time/timer.c:1549 [inline]
       __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
       run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
       handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
       __do_softirq kernel/softirq.c:630 [inline]
       invoke_softirq kernel/softirq.c:470 [inline]
       __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
       irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
       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
       memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:63
       kasan_save_stack mm/kasan/common.c:42 [inline]
       kasan_set_track+0x3c/0x70 mm/kasan/common.c:52
       kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
       ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
       kasan_slab_free include/linux/kasan.h:177 [inline]
       slab_free_hook mm/slub.c:1724 [inline]
       slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750
       slab_free mm/slub.c:3661 [inline]
       __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674
       __vunmap+0x942/0xa00 mm/vmalloc.c:2724
       bpf_prog_calc_tag+0x53a/0x630 kernel/bpf/core.c:343
       resolve_pseudo_ldimm64+0xd4/0x11d0 kernel/bpf/verifier.c:13024
       bpf_check+0x3d97/0x10ca0 kernel/bpf/verifier.c:15558
       bpf_prog_load+0x1072/0x15a0 kernel/bpf/syscall.c:2641
       __sys_bpf+0x520/0x6d0 kernel/bpf/syscall.c:5020
       __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
       __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
       __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 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.2.2323/13915:
 #0: ffffc900001e0bc0 ((&app->join_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc1/0x670 kernel/time/timer.c:1501
 #1: ffff888058390cc8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
 #1: ffff888058390cc8 (&app->lock){+.-.}-{2:2}, at: mrp_join_timer+0xd4/0x170 net/802/mrp.c:609
 #2: ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
 #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
 #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
 #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
 #3: ffffffff8c92aaa0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf0/0x400 kernel/trace/bpf_trace.c:2325

stack backtrace:
CPU: 1 PID: 13915 Comm: syz.2.2323 Not tainted 6.1.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 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+0x184/0x870 kernel/rcu/tree.c:3402
 trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
 bpf_prog_2c29ac5cdc6b1842+0x3a/0x3e
 bpf_dispatcher_nop_func include/linux/bpf.h:1001 [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:2285 [inline]
 bpf_trace_run3+0x1e3/0x400 kernel/trace/bpf_trace.c:2325
 trace_timer_start include/trace/events/timer.h:53 [inline]
 enqueue_timer+0x411/0x5c0 kernel/time/timer.c:609
 internal_add_timer kernel/time/timer.c:634 [inline]
 __mod_timer+0x8e1/0xd20 kernel/time/timer.c:1115
 mrp_join_timer_arm net/802/mrp.c:596 [inline]
 mrp_join_timer+0x13b/0x170 net/802/mrp.c:611
 call_timer_fn+0x1a0/0x670 kernel/time/timer.c:1504
 expire_timers kernel/time/timer.c:1549 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1820
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1833
 handle_softirqs+0x2a1/0x920 kernel/softirq.c:596
 __do_softirq kernel/softirq.c:630 [inline]
 invoke_softirq kernel/softirq.c:470 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:679
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
 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:memset_erms+0x9/0x10 arch/x86/lib/memset_64.S:64
Code: c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 f3 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 <f3> aa 4c 89 c8 c3 90 49 89 fa 40 0f b6 ce 48 b8 01 01 01 01 01 01
RSP: 0018:ffffc90003236d98 EFLAGS: 00010202
RAX: 0000000000003600 RBX: ffff8880534959d0 RCX: 0000000000000100
RDX: 0000000000000200 RSI: 0000000000000000 RDI: ffffc90003236ea0
RBP: ffffc90003236fd0 R08: dffffc0000000000 R09: ffffc90003236da0
R10: 0000000000000000 R11: 0000000000000038 R12: 0000000000000000
R13: ffffc90003237080 R14: 0000000000000800 R15: ffffc90003236da0
 kasan_save_stack mm/kasan/common.c:42 [inline]
 kasan_set_track+0x3c/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750
 slab_free mm/slub.c:3661 [inline]
 __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674
 __vunmap+0x942/0xa00 mm/vmalloc.c:2724
 bpf_prog_calc_tag+0x53a/0x630 kernel/bpf/core.c:343
 resolve_pseudo_ldimm64+0xd4/0x11d0 kernel/bpf/verifier.c:13024
 bpf_check+0x3d97/0x10ca0 kernel/bpf/verifier.c:15558
 bpf_prog_load+0x1072/0x15a0 kernel/bpf/syscall.c:2641
 __sys_bpf+0x520/0x6d0 kernel/bpf/syscall.c:5020
 __do_sys_bpf kernel/bpf/syscall.c:5124 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5122 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:5122
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f57a718e929
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:00007f57a7fba038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f57a73b5fa0 RCX: 00007f57a718e929
RDX: 0000000000000094 RSI: 00002000000007c0 RDI: 0000000000000005
RBP: 00007f57a7210b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f57a73b5fa0 R15: 00007fff1cb981a8
 </TASK>
----------------
Code disassembly (best guess):
   0:	c1 e9 03             	shr    $0x3,%ecx
   3:	40 0f b6 f6          	movzbl %sil,%esi
   7:	48 b8 01 01 01 01 01 	movabs $0x101010101010101,%rax
   e:	01 01 01
  11:	48 0f af c6          	imul   %rsi,%rax
  15:	f3 48 ab             	rep stos %rax,%es:(%rdi)
  18:	89 d1                	mov    %edx,%ecx
  1a:	f3 aa                	rep stos %al,%es:(%rdi)
  1c:	4c 89 c8             	mov    %r9,%rax
  1f:	c3                   	ret
  20:	90                   	nop
  21:	49 89 f9             	mov    %rdi,%r9
  24:	40 88 f0             	mov    %sil,%al
  27:	48 89 d1             	mov    %rdx,%rcx
* 2a:	f3 aa                	rep stos %al,%es:(%rdi) <-- trapping instruction
  2c:	4c 89 c8             	mov    %r9,%rax
  2f:	c3                   	ret
  30:	90                   	nop
  31:	49 89 fa             	mov    %rdi,%r10
  34:	40 0f b6 ce          	movzbl %sil,%ecx
  38:	48                   	rex.W
  39:	b8 01 01 01 01       	mov    $0x1010101,%eax
  3e:	01 01                	add    %eax,(%rcx)