======================================================
WARNING: possible circular locking dependency detected
6.1.138-syzkaller #0 Not tainted
------------------------------------------------------
syz.9.3593/14338 is trying to acquire lock:
ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2991 [inline]
ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3311 [inline]
ffff8880b8e281d8 (krc.lock){..-.}-{2:2}, at: kvfree_call_rcu+0x184/0x870 kernel/rcu/tree.c:3402
but task is already holding lock:
ffff8880b8e28418 (&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:1770
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_5186c38a4019a4cb+0x42/0x46
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_periodic_timer_arm net/802/mrp.c:617 [inline]
mrp_periodic_timer+0x1c5/0x200 net/802/mrp.c:629
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:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x12f/0x220 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
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1611 [inline]
folio_batch_move_lru+0x53f/0x6a0 mm/swap.c:244
folio_add_lru+0x42a/0xd50 mm/swap.c:526
do_anonymous_page mm/memory.c:4231 [inline]
handle_pte_fault mm/memory.c:5029 [inline]
__handle_mm_fault mm/memory.c:5173 [inline]
handle_mm_fault+0x3502/0x3e70 mm/memory.c:5294
do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
handle_page_fault arch/x86/mm/fault.c:1431 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
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 ***
7 locks held by syz.9.3593/14338:
#0: ffff888072c6e2d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_trylock include/linux/mmap_lock.h:136 [inline]
#0: ffff888072c6e2d8 (&mm->mmap_lock){++++}-{3:3}, at: get_mmap_lock_carefully mm/memory.c:5322 [inline]
#0: ffff888072c6e2d8 (&mm->mmap_lock){++++}-{3:3}, at: lock_mm_and_find_vma+0x2e/0x2f0 mm/memory.c:5384
#1: ffff888077e53078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#1: ffff888077e53078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: do_anonymous_page mm/memory.c:4211 [inline]
#1: ffff888077e53078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: handle_pte_fault mm/memory.c:5029 [inline]
#1: ffff888077e53078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: __handle_mm_fault mm/memory.c:5173 [inline]
#1: ffff888077e53078 (ptlock_ptr(page)#2){+.+.}-{2:2}, at: handle_mm_fault+0x334f/0x3e70 mm/memory.c:5294
#2: ffff8880b8e35838 (lock#4){+.+.}-{2:2}, at: local_lock_acquire include/linux/local_lock_internal.h:29 [inline]
#2: ffff8880b8e35838 (lock#4){+.+.}-{2:2}, at: folio_add_lru+0x316/0xd50 mm/swap.c:524
#3: ffffc90000007bc0 ((&app->periodic_timer)){+.-.}-{0:0}, at: call_timer_fn+0xc1/0x670 kernel/time/timer.c:1501
#4: ffff888055a7acc8 (&app->lock){+.-.}-{2:2}, at: spin_lock include/linux/spinlock.h:351 [inline]
#4: ffff888055a7acc8 (&app->lock){+.-.}-{2:2}, at: mrp_periodic_timer+0x2c/0x200 net/802/mrp.c:625
#5: ffff8880b8e28418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base+0x123/0x270 kernel/time/timer.c:999
#6: ffffffff8c92a960 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
#6: ffffffff8c92a960 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:791 [inline]
#6: ffffffff8c92a960 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2284 [inline]
#6: ffffffff8c92a960 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run3+0xf0/0x400 kernel/trace/bpf_trace.c:2325
stack backtrace:
CPU: 0 PID: 14338 Comm: syz.9.3593 Not tainted 6.1.138-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
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: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_5186c38a4019a4cb+0x42/0x46
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_periodic_timer_arm net/802/mrp.c:617 [inline]
mrp_periodic_timer+0x1c5/0x200 net/802/mrp.c:629
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:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0x12f/0x220 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
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 ae e3 6d f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 36 5e 3e f7 65 8b 05 37 23 e9 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0000:ffffc90005277ac0 EFLAGS: 00000206
RAX: 1db237b2dae39b00 RBX: 0000000000000a06 RCX: 1db237b2dae39b00
RDX: dffffc0000000000 RSI: ffffffff8a6bfe00 RDI: 0000000000000001
RBP: ffffc90005277b50 R08: dffffc0000000000 R09: fffffbfff2117051
R10: fffffbfff2117051 R11: 1ffffffff2117050 R12: dffffc0000000000
R13: dffffc0000000000 R14: ffff888078d54050 R15: 1ffff92000a4ef58
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
unlock_page_lruvec_irqrestore include/linux/memcontrol.h:1611 [inline]
folio_batch_move_lru+0x53f/0x6a0 mm/swap.c:244
folio_add_lru+0x42a/0xd50 mm/swap.c:526
do_anonymous_page mm/memory.c:4231 [inline]
handle_pte_fault mm/memory.c:5029 [inline]
__handle_mm_fault mm/memory.c:5173 [inline]
handle_mm_fault+0x3502/0x3e70 mm/memory.c:5294
do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340
handle_page_fault arch/x86/mm/fault.c:1431 [inline]
exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0033:0x7ff10cc54fe1
Code: 48 8b 54 24 08 48 85 d2 74 17 8b 44 24 18 0f c8 89 c0 48 89 44 24 18 48 83 fa 01 0f 85 b3 01 00 00 48 8b 44 24 10 8b 54 24 18 <89> 10 e9 15 fd ff ff 48 8b 44 24 10 8b 10 48 8b 44 24 08 48 85 c0
RSP: 002b:00007ffda9d35470 EFLAGS: 00010246
RAX: 0000200000000200 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 0000000000000004 RSI: 0000000000000000 RDI: 000055556528a3c8
RBP: 00007ffda9d35578 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 00000000000927c0 R14: fffffffffffffffe R15: 00007ffda9d35760
----------------
Code disassembly (best guess):
0: 74 05 je 0x7
2: e8 ae e3 6d f7 call 0xf76de3b5
7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp)
e: 00 00
10: 9c pushf
11: 8f 44 24 20 pop 0x20(%rsp)
15: f6 44 24 21 02 testb $0x2,0x21(%rsp)
1a: 75 4b jne 0x67
1c: f7 c3 00 02 00 00 test $0x200,%ebx
22: 74 01 je 0x25
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 36 5e 3e f7 call 0xf73e5e65 <-- trapping instruction
2f: 65 8b 05 37 23 e9 75 mov %gs:0x75e92337(%rip),%eax # 0x75e9236d
36: 85 c0 test %eax,%eax
38: 74 3c je 0x76
3a: 48 rex.W
3b: c7 .byte 0xc7
3c: 04 24 add $0x24,%al
3e: 0e (bad)
3f: 36 ss