======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
kworker/u4:0/9 is trying to acquire lock:
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2995 [inline]
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
ffff8880b8f281d8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406
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:3176 [inline]
kvfree_call_rcu+0x4cb/0x870 kernel/rcu/tree.c:3432
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:3796
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:2995 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406
trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
bpf_prog_5186c38a4019a4cb+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1012 [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
preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
lockdep_unregister_key+0x4c3/0x530 kernel/locking/lockdep.c:6370
wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
destroy_workqueue+0x87b/0xb20 kernel/workqueue.c:4469
wg_destruct+0x1e8/0x300 drivers/net/wireguard/device.c:257
netdev_run_todo+0xbc9/0xd80 net/core/dev.c:10513
default_device_exit_batch+0x9c8/0xa50 net/core/dev.c:11504
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
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 ***
8 locks held by kworker/u4:0/9:
#0: ffff888017616938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#1: ffffc900000e7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x7a1/0x1160 kernel/workqueue.c:2267
#2: ffffffff8dd34710 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x132/0xb80 net/core/net_namespace.c:594
#3: ffff888056a713e8 (&wg->device_update_lock){+.+.}-{3:3}, at: wg_destruct+0x112/0x300 drivers/net/wireguard/device.c:249
#4: ffffc900001e0bc0 ((&app->join_timer)#2){+.-.}-{0:0}, at: call_timer_fn+0xc1/0x670 kernel/time/timer.c:1501
#5: ffff888026ef80c8 (&app->lock#2){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#5: ffff888026ef80c8 (&app->lock#2){+.-.}-{2:2}, at: mrp_join_timer+0xd4/0x170 net/802/mrp.c:609
#6: ffff8880b8f28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
#7: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#7: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#7: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
#7: ffffffff8cb2abe0 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf0/0x400 kernel/trace/bpf_trace.c:2325
stack backtrace:
CPU: 1 PID: 9 Comm: kworker/u4:0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: netns cleanup_net
Call Trace:
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:2995 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3315 [inline]
kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3406
trie_delete_elem+0x52d/0x690 kernel/bpf/lpm_trie.c:545
bpf_prog_5186c38a4019a4cb+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1012 [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
RIP: 0010:preempt_schedule_irq+0xac/0x150 kernel/sched/core.c:6873
Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 70 bf 01 00 00 00 e8 5f 70 37 f7 e8 9a e6 66 f7 fb bf 01 00 00 00 df b9 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24
RSP: 0000:ffffc900000e7620 EFLAGS: 00000282
RAX: 6586db8b30916b00 RBX: 0000000000000000 RCX: 6586db8b30916b00
RDX: dffffc0000000000 RSI: ffffffff8a8c0500 RDI: 0000000000000001
RBP: ffffc900000e76c0 R08: dffffc0000000000 R09: fffffbfff215c466
R10: fffffbfff215c466 R11: 1ffffffff215c465 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff9200001cec4
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696
RIP: 0010:lockdep_unregister_key+0x4c3/0x530 kernel/locking/lockdep.c:6370
Code: 21 a9 90 48 c7 c6 30 99 63 81 e8 a8 93 07 00 e8 03 a7 07 00 e9 86 fc ff ff e8 49 09 b4 08 41 f7 c4 00 02 00 00 74 d1 fb 84 db <75> d0 eb e1 0f 0b eb a1 0f 0b e9 11 ff ff ff 0f 0b e9 5e ff ff ff
RSP: 0000:ffffc900000e7780 EFLAGS: 00000246
RAX: 6586db8b30916b00 RBX: 0000000000000000 RCX: 6586db8b30916b00
RDX: 0000000000000001 RSI: ffffffff8a8c11e0 RDI: ffffffff8adef020
RBP: ffffc900000e7860 R08: dffffc0000000000 R09: fffffbfff2156659
R10: fffffbfff2156659 R11: 1ffffffff2156658 R12: 0000000000000a07
R13: ffff88802fc66929 R14: ffffffff90ab21a8 R15: 1ffff9200001cef4
wq_unregister_lockdep kernel/workqueue.c:3500 [inline]
destroy_workqueue+0x87b/0xb20 kernel/workqueue.c:4469
wg_destruct+0x1e8/0x300 drivers/net/wireguard/device.c:257
netdev_run_todo+0xbc9/0xd80 net/core/dev.c:10513
default_device_exit_batch+0x9c8/0xa50 net/core/dev.c:11504
ops_exit_list net/core/net_namespace.c:177 [inline]
cleanup_net+0x77b/0xb80 net/core/net_namespace.c:640
process_one_work+0x898/0x1160 kernel/workqueue.c:2292
worker_thread+0xaa2/0x1250 kernel/workqueue.c:2439
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
----------------
Code disassembly (best guess):
0: 44 24 20 rex.R and $0x20,%al
3: f6 44 24 21 02 testb $0x2,0x21(%rsp)
8: 74 0b je 0x15
a: 0f 0b ud2
c: 48 f7 03 08 00 00 00 testq $0x8,(%rbx)
13: 74 70 je 0x85
15: bf 01 00 00 00 mov $0x1,%edi
1a: e8 5f 70 37 f7 call 0xf737707e
1f: e8 9a e6 66 f7 call 0xf766e6be
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 df b9 ff ff call 0xffffba0e <-- trapping instruction
2f: 48 c7 44 24 40 00 00 movq $0x0,0x40(%rsp)
36: 00 00
38: 9c pushf
39: 8f 44 24 40 pop 0x40(%rsp)
3d: 8b .byte 0x8b
3e: 44 rex.R
3f: 24 .byte 0x24