======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.8.125/5272 is trying to acquire lock:
ffff88807ad5ca38 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
but task is already holding lock:
ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1749
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (hrtimer_bases.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_hrtimer_base kernel/time/hrtimer.c:168 [inline]
hrtimer_start_range_ns+0xff/0xc20 kernel/time/hrtimer.c:1284
hrtimer_start include/linux/hrtimer.h:420 [inline]
run_page_cache_worker kernel/rcu/tree.c:3492 [inline]
kvfree_call_rcu+0x60d/0x7c0 kernel/rcu/tree.c:3603
rtnl_register_internal+0x44e/0x540 net/core/rtnetlink.c:223
rtnl_register+0x2e/0x70 net/core/rtnetlink.c:273
ip_rt_init+0x2e0/0x3a0 net/ipv4/route.c:3798
ip_init+0xa/0x20 net/ipv4/ip_output.c:1749
inet_init+0x28b/0x3a0 net/ipv4/af_inet.c:2007
do_one_initcall+0x1ee/0x680 init/main.c:1302
do_initcall_level+0x137/0x1f0 init/main.c:1375
do_initcalls+0x4b/0x90 init/main.c:1391
kernel_init_freeable+0x3ce/0x560 init/main.c:1615
kernel_init+0x19/0x1b0 init/main.c:1506
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
-> #1 (krc.lock){..-.}-{2:2}:
__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:3203 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3510 [inline]
kvfree_call_rcu+0x186/0x7c0 kernel/rcu/tree.c:3601
trie_update_elem+0x86e/0xc50 kernel/bpf/lpm_trie.c:396
bpf_map_update_value+0x57d/0x650 kernel/bpf/syscall.c:223
generic_map_update_batch+0x525/0x7c0 kernel/bpf/syscall.c:1430
bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
__sys_bpf+0x601/0x670 kernel/bpf/syscall.c:-1
__do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
__se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
__x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #0 (&trie->lock){-.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
bpf_prog_2c29ac5cdc6b1842+0x3a/0x62c
bpf_dispatcher_nop_func include/linux/bpf.h:888 [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_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915
trace_hrtimer_start include/trace/events/timer.h:199 [inline]
debug_activate kernel/time/hrtimer.c:466 [inline]
enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1069
__run_hrtimer kernel/time/hrtimer.c:1702 [inline]
__hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
rcu_preempt_deferred_qs_irqrestore+0x836/0xc10 kernel/rcu/tree_plugin.h:-1
rcu_read_unlock_special+0x3cc/0x480 kernel/rcu/tree_plugin.h:673
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:771 [inline]
inet_twsk_purge+0x778/0x810 net/ipv4/inet_timewait_sock.c:309
ops_exit_list net/core/net_namespace.c:177 [inline]
setup_net+0x822/0x9f0 net/core/net_namespace.c:365
copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
copy_process+0x180f/0x3e00 kernel/fork.c:2293
kernel_clone+0x219/0x930 kernel/fork.c:2679
__do_sys_clone kernel/fork.c:2796 [inline]
__se_sys_clone kernel/fork.c:2780 [inline]
__x64_sys_clone+0x170/0x1c0 kernel/fork.c:2780
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
other info that might help us debug this:
Chain exists of:
&trie->lock --> krc.lock --> hrtimer_bases.lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(hrtimer_bases.lock);
lock(krc.lock);
lock(hrtimer_bases.lock);
lock(&trie->lock);
*** DEADLOCK ***
4 locks held by syz.8.125/5272:
#0: ffffffff8d22c690 (pernet_ops_rwsem){++++}-{3:3}, at: copy_net_ns+0x32e/0x5b0 net/core/net_namespace.c:499
#1: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
#2: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
#2: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5ff/0xc40 kernel/time/hrtimer.c:1749
#3: ffffffff8c11c660 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:311
stack backtrace:
CPU: 0 PID: 5272 Comm: syz.8.125 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3788 [inline]
__lock_acquire+0x2c33/0x7c60 kernel/locking/lockdep.c:5012
lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa4/0xf0 kernel/locking/spinlock.c:162
trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
bpf_prog_2c29ac5cdc6b1842+0x3a/0x62c
bpf_dispatcher_nop_func include/linux/bpf.h:888 [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_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915
trace_hrtimer_start include/trace/events/timer.h:199 [inline]
debug_activate kernel/time/hrtimer.c:466 [inline]
enqueue_hrtimer+0x314/0x370 kernel/time/hrtimer.c:1069
__run_hrtimer kernel/time/hrtimer.c:1702 [inline]
__hrtimer_run_queues+0x65a/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 ae 4b cb 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 d5 9e f7 65 8b 05 17 d3 4f 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc9000387f440 EFLAGS: 00000206
RAX: 75d98492c43af000 RBX: 0000000000000246 RCX: 75d98492c43af000
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: 0000000000000001
RBP: ffffc9000387f4d0 R08: dffffc0000000000 R09: fffffbfff1ff7a1a
R10: fffffbfff1ff7a1a R11: 1ffffffff1ff7a19 R12: dffffc0000000000
R13: ffffffff8c120b00 R14: ffffffff8c120ac0 R15: 1ffff9200070fe88
rcu_preempt_deferred_qs_irqrestore+0x836/0xc10 kernel/rcu/tree_plugin.h:-1
rcu_read_unlock_special+0x3cc/0x480 kernel/rcu/tree_plugin.h:673
__rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
rcu_read_unlock include/linux/rcupdate.h:771 [inline]
inet_twsk_purge+0x778/0x810 net/ipv4/inet_timewait_sock.c:309
ops_exit_list net/core/net_namespace.c:177 [inline]
setup_net+0x822/0x9f0 net/core/net_namespace.c:365
copy_net_ns+0x348/0x5b0 net/core/net_namespace.c:503
create_new_namespaces+0x3d3/0x6f0 kernel/nsproxy.c:110
copy_namespaces+0x37d/0x3e0 kernel/nsproxy.c:178
copy_process+0x180f/0x3e00 kernel/fork.c:2293
kernel_clone+0x219/0x930 kernel/fork.c:2679
__do_sys_clone kernel/fork.c:2796 [inline]
__se_sys_clone kernel/fork.c:2780 [inline]
__x64_sys_clone+0x170/0x1c0 kernel/fork.c:2780
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f44f4b6eec9
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:00007f44f2dd5fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007f44f4dc5fa0 RCX: 00007f44f4b6eec9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000630c1000
RBP: 00007f44f4bf1f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f44f4dc6038 R14: 00007f44f4dc5fa0 R15: 00007ffde68d32c8
----------------
Code disassembly (best guess):
0: 74 05 je 0x7
2: e8 ae 4b cb f7 call 0xf7cb4bb5
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 d5 9e f7 call 0xf79ed565 <-- trapping instruction
2f: 65 8b 05 17 d3 4f 76 mov %gs:0x764fd317(%rip),%eax # 0x764fd34d
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