======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.1.2624/13024 is trying to acquire lock:
ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: krc_this_cpu_lock kernel/rcu/tree.c:2959 [inline]
ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline]
ffff8880b8f29370 (krc.lock){-.-.}-{2:2}, at: kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3453
but task is already holding lock:
ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1814
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (hrtimer_bases.lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
lock_hrtimer_base kernel/time/hrtimer.c:181 [inline]
hrtimer_start_range_ns+0xf3/0x1000 kernel/time/hrtimer.c:1349
hrtimer_start include/linux/hrtimer.h:421 [inline]
run_page_cache_worker kernel/rcu/tree.c:3350 [inline]
kvfree_call_rcu+0x5d5/0x780 kernel/rcu/tree.c:3455
rtnl_register_internal+0x486/0x590 net/core/rtnetlink.c:264
rtnl_register+0x32/0x70 net/core/rtnetlink.c:314
ip_rt_init+0x2ec/0x390 net/ipv4/route.c:3796
ip_init+0xe/0x20 net/ipv4/ip_output.c:1663
inet_init+0x2c1/0x3e0 net/ipv4/af_inet.c:2024
do_one_initcall+0x1fd/0x750 init/main.c:1238
do_initcall_level+0x137/0x1f0 init/main.c:1300
do_initcalls+0x69/0xd0 init/main.c:1316
kernel_init_freeable+0x3d2/0x570 init/main.c:1553
kernel_init+0x1d/0x1c0 init/main.c:1443
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
-> #0 (krc.lock){-.-.}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
krc_this_cpu_lock kernel/rcu/tree.c:2959 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline]
kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3453
trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545
bpf_prog_5186c38a4019a4cb+0x4a/0x4e
bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline]
__bpf_prog_run include/linux/filter.h:612 [inline]
bpf_prog_run include/linux/filter.h:619 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361
__bpf_trace_hrtimer_start+0xfb/0x150 include/trace/events/timer.h:202
trace_hrtimer_start include/trace/events/timer.h:202 [inline]
debug_activate kernel/time/hrtimer.c:506 [inline]
enqueue_hrtimer+0x318/0x370 kernel/time/hrtimer.c:1108
__run_hrtimer kernel/time/hrtimer.c:1767 [inline]
__hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1814
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
__sanitizer_cov_trace_pc+0x0/0x60
__orc_find arch/x86/kernel/unwind_orc.c:99 [inline]
orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
unwind_next_frame+0x501/0x2970 arch/x86/kernel/unwind_orc.c:494
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
rcu_do_batch kernel/rcu/tree.c:2194 [inline]
rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
perf_copy_attr+0x0/0x840
__do_sys_perf_event_open kernel/events/core.c:12589 [inline]
__se_sys_perf_event_open+0xf0/0x1c20 kernel/events/core.c:12566
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 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(hrtimer_bases.lock);
lock(krc.lock);
lock(hrtimer_bases.lock);
lock(krc.lock);
*** DEADLOCK ***
3 locks held by syz.1.2624/13024:
#0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2188 [inline]
#0: ffffffff8cd2ff40 (rcu_callback){....}-{0:0}, at: rcu_core+0xc51/0x1720 kernel/rcu/tree.c:2467
#1: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
#1: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1814
#2: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#2: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#2: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
#2: ffffffff8cd2fe20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361
stack backtrace:
CPU: 1 PID: 13024 Comm: syz.1.2624 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
check_noncircular+0x2bd/0x3c0 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2ddb/0x7c80 kernel/locking/lockdep.c:5137
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
krc_this_cpu_lock kernel/rcu/tree.c:2959 [inline]
add_ptr_to_bulk_krc_lock kernel/rcu/tree.c:3368 [inline]
kvfree_call_rcu+0x15a/0x780 kernel/rcu/tree.c:3453
trie_delete_elem+0x535/0x6a0 kernel/bpf/lpm_trie.c:545
bpf_prog_5186c38a4019a4cb+0x4a/0x4e
bpf_dispatcher_nop_func include/linux/bpf.h:1223 [inline]
__bpf_prog_run include/linux/filter.h:612 [inline]
bpf_prog_run include/linux/filter.h:619 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
bpf_trace_run2+0x1d1/0x3c0 kernel/trace/bpf_trace.c:2361
__bpf_trace_hrtimer_start+0xfb/0x150 include/trace/events/timer.h:202
trace_hrtimer_start include/trace/events/timer.h:202 [inline]
debug_activate kernel/time/hrtimer.c:506 [inline]
enqueue_hrtimer+0x318/0x370 kernel/time/hrtimer.c:1108
__run_hrtimer kernel/time/hrtimer.c:1767 [inline]
__hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1814
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1876
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d 3c fc c4 0c 48 89 de 5b e9 73 7a 56 00 cc cc cc 0f 1e fa 48 8b 04 24 65 48 8b 0d 10 20 7e 7e 65 8b 15 11 20 7e
RSP: 0018:ffffc900001f06b0 EFLAGS: 00000212
RAX: ffffffff8ec392f8 RBX: ffffffff8ec392fc RCX: ffff88807ea5bc00
RDX: 0000000000000100 RSI: ffffffff8a6e4163 RDI: ffffffff8a6e4152
RBP: ffffffff8ec392fc R08: ffffc900001f0850 R09: 0000000000000009
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff8ec39300
R13: ffffffff8a6e4152 R14: ffffffff8a6e4163 R15: ffffffff8ec392fc
__orc_find arch/x86/kernel/unwind_orc.c:99 [inline]
orc_find arch/x86/kernel/unwind_orc.c:227 [inline]
unwind_next_frame+0x501/0x2970 arch/x86/kernel/unwind_orc.c:494
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:45 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
kasan_slab_free include/linux/kasan.h:164 [inline]
slab_free_hook mm/slub.c:1811 [inline]
slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x280 mm/slub.c:3852
rcu_do_batch kernel/rcu/tree.c:2194 [inline]
rcu_core+0xcc4/0x1720 kernel/rcu/tree.c:2467
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:perf_copy_attr+0x0/0x840 kernel/events/core.c:12271
Code: 41 5e 41 5f 5d c3 44 89 f1 80 e1 07 80 c1 03 38 c1 7c da 4c 89 f7 e8 1f bd 2d 00 eb d0 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 20 48 89 f3 49 89 ff e8 57
RSP: 0018:ffffc9000ba17d38 EFLAGS: 00000246
RAX: ffffc9000ba17de0 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffc9000ba17de0 RDI: 0000200000000100
RBP: ffffc9000ba17f10 R08: ffffc9000ba17e67 R09: 0000000000000000
R10: ffffc9000ba17de0 R11: fffff52001742fcd R12: 0000200000000100
R13: 1ffff92001742fb8 R14: ffffc9000ba17de0 R15: dffffc0000000000
__do_sys_perf_event_open kernel/events/core.c:12589 [inline]
__se_sys_perf_event_open+0xf0/0x1c20 kernel/events/core.c:12566
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f854f78ec29
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:00007f85506bb038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f854f9d5fa0 RCX: 00007f854f78ec29
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000100
RBP: 00007f854f811e41 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f854f9d6038 R14: 00007f854f9d5fa0 R15: 00007ffd113d1918
----------------
Code disassembly (best guess), 1 bytes skipped:
0: 0f 0b ud2
2: 0f 1f 80 00 00 00 00 nopl 0x0(%rax)
9: f3 0f 1e fa endbr64
d: 53 push %rbx
e: 48 89 fb mov %rdi,%rbx
11: e8 13 00 00 00 call 0x29
16: 48 8b 3d 3c fc c4 0c mov 0xcc4fc3c(%rip),%rdi # 0xcc4fc59
1d: 48 89 de mov %rbx,%rsi
20: 5b pop %rbx
21: e9 73 7a 56 00 jmp 0x567a99
26: cc int3
27: cc int3
28: cc int3
* 29: f3 0f 1e fa endbr64 <-- trapping instruction
2d: 48 8b 04 24 mov (%rsp),%rax
31: 65 48 8b 0d 10 20 7e mov %gs:0x7e7e2010(%rip),%rcx # 0x7e7e2049
38: 7e
39: 65 gs
3a: 8b .byte 0x8b
3b: 15 .byte 0x15
3c: 11 20 adc %esp,(%rax)
3e: 7e .byte 0x7e