======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.6.1479/10503 is trying to acquire lock:
ffff888078dd5238 (&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: hrtimer_interrupt+0xf8/0x8d0 kernel/time/hrtimer.c:1792
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+0xb0/0x100 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+0x61b/0x7d0 kernel/rcu/tree.c:3603
rtnl_register_internal+0x489/0x590 net/core/rtnetlink.c:225
rtnl_register+0x2e/0x70 net/core/rtnetlink.c:275
ip_rt_init+0x2e0/0x3a0 net/ipv4/route.c:3803
ip_init+0xa/0x20 net/ipv4/ip_output.c:1758
inet_init+0x28b/0x3a0 net/ipv4/af_inet.c:2007
do_one_initcall+0x272/0x730 init/main.c:1316
do_initcall_level+0x137/0x1f0 init/main.c:1389
do_initcalls+0x4b/0x90 init/main.c:1405
kernel_init_freeable+0x3e9/0x570 init/main.c:1629
kernel_init+0x19/0x1b0 init/main.c:1520
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+0x18d/0x7d0 kernel/rcu/tree.c:3601
trie_update_elem+0x86c/0xc50 kernel/bpf/lpm_trie.c:396
bpf_map_update_value+0x57d/0x650 kernel/bpf/syscall.c:223
generic_map_update_batch+0x52d/0x7d0 kernel/bpf/syscall.c:1430
bpf_map_do_batch+0x466/0x600 kernel/bpf/syscall.c:-1
__sys_bpf+0x671/0x6f0 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
bpf_prog_2c29ac5cdc6b1842+0x3a/0xc10
bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
__bpf_prog_run include/linux/filter.h:621 [inline]
bpf_prog_run include/linux/filter.h:635 [inline]
BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline]
trace_call_bpf+0x32d/0x5b0 kernel/trace/bpf_trace.c:127
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
perf_trace_lock_acquire+0x340/0x3e0 include/trace/events/lock.h:13
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103
ktime_get_update_offsets_now+0x44/0x3e0 kernel/time/timekeeping.c:2300
hrtimer_update_base kernel/time/hrtimer.c:621 [inline]
hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793
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
finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
freezable_schedule include/linux/freezer.h:172 [inline]
futex_wait_queue_me+0x22d/0x440 kernel/futex/core.c:2863
futex_wait+0x256/0x680 kernel/futex/core.c:2964
do_futex+0xdb2/0x12b0 kernel/futex/core.c:3983
__do_sys_futex kernel/futex/core.c:4060 [inline]
__se_sys_futex+0x389/0x420 kernel/futex/core.c:4041
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 ***
2 locks held by syz.6.1479/10503:
#0: ffff8880b902a258 (hrtimer_bases.lock){-.-.}-{2:2}, at: hrtimer_interrupt+0xf8/0x8d0 kernel/time/hrtimer.c:1792
#1: ffffffff8c31f320 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:312
stack backtrace:
CPU: 0 PID: 10503 Comm: syz.6.1479 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
check_noncircular+0x296/0x330 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+0x2c42/0x7d10 kernel/locking/lockdep.c:5012
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb0/0x100 kernel/locking/spinlock.c:162
trie_delete_elem+0x90/0x710 kernel/bpf/lpm_trie.c:467
bpf_prog_2c29ac5cdc6b1842+0x3a/0xc10
bpf_dispatcher_nop_func include/linux/bpf.h:888 [inline]
__bpf_prog_run include/linux/filter.h:621 [inline]
bpf_prog_run include/linux/filter.h:635 [inline]
BPF_PROG_RUN_ARRAY include/linux/bpf.h:1439 [inline]
trace_call_bpf+0x32d/0x5b0 kernel/trace/bpf_trace.c:127
perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:10016
perf_trace_lock_acquire+0x340/0x3e0 include/trace/events/lock.h:13
trace_lock_acquire include/trace/events/lock.h:13 [inline]
lock_acquire+0x3d7/0x400 kernel/locking/lockdep.c:5594
seqcount_lockdep_reader_access+0xcd/0x1d0 include/linux/seqlock.h:103
ktime_get_update_offsets_now+0x44/0x3e0 kernel/time/timekeeping.c:2300
hrtimer_update_base kernel/time/hrtimer.c:621 [inline]
hrtimer_interrupt+0x130/0x8d0 kernel/time/hrtimer.c:1793
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:finish_lock_switch+0x134/0x280 kernel/sched/core.c:4804
Code: be ff ff ff ff e8 dc 60 68 08 85 c0 74 4a 4d 85 ff 75 66 0f 1f 44 00 00 48 89 df e8 86 cc 71 08 e8 81 e6 2a 00 fb 48 83 c4 08 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 48 89 df e8 c9 09 fe ff 43 80 3c
RSP: 0018:ffffc90002e3f788 EFLAGS: 00000286
RAX: 33deeffe2be13a00 RBX: ffff8880b903a340 RCX: 33deeffe2be13a00
RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: ffffffff8a7a0700
RBP: 1ffff11017207613 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 1ffff110172075c1
R13: dffffc0000000000 R14: ffff8880b903ae08 R15: 0000000000000000
finish_task_switch+0x12f/0x640 kernel/sched/core.c:4921
context_switch kernel/sched/core.c:5052 [inline]
__schedule+0x11f7/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
freezable_schedule include/linux/freezer.h:172 [inline]
futex_wait_queue_me+0x22d/0x440 kernel/futex/core.c:2863
futex_wait+0x256/0x680 kernel/futex/core.c:2964
do_futex+0xdb2/0x12b0 kernel/futex/core.c:3983
__do_sys_futex kernel/futex/core.c:4060 [inline]
__se_sys_futex+0x389/0x420 kernel/futex/core.c:4041
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: 0033:0x7f11c2095e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe987f70e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00000000000446e6 RCX: 00007f11c2095e59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f11c230efac
RBP: 0000000000000032 R08: 00112c1dbe5553af R09: 0000000000000000
R10: 00007ffe987f71f0 R11: 0000000000000246 R12: 00007ffe987f7210
R13: 00007f11c230efac R14: 0000000000044718 R15: 00007ffe987f71f0
----------------
Code disassembly (best guess):
0: be ff ff ff ff mov $0xffffffff,%esi
5: e8 dc 60 68 08 call 0x86860e6
a: 85 c0 test %eax,%eax
c: 74 4a je 0x58
e: 4d 85 ff test %r15,%r15
11: 75 66 jne 0x79
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 48 89 df mov %rbx,%rdi
1b: e8 86 cc 71 08 call 0x871cca6
20: e8 81 e6 2a 00 call 0x2ae6a6
25: fb sti
26: 48 83 c4 08 add $0x8,%rsp
* 2a: 5b pop %rbx <-- trapping instruction
2b: 41 5c pop %r12
2d: 41 5d pop %r13
2f: 41 5e pop %r14
31: 41 5f pop %r15
33: 5d pop %rbp
34: c3 ret
35: 48 89 df mov %rbx,%rdi
38: e8 c9 09 fe ff call 0xfffe0a06
3d: 43 rex.XB
3e: 80 .byte 0x80
3f: 3c .byte 0x3c