======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz-executor/6811 is trying to acquire lock:
ffff88807e131a38 (&trie->lock){-.-.}-{2:2}, at: trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466
but task is already holding lock:
ffffffff975b3140 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:1034 [inline]
ffffffff975b3140 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0x9e/0x520 lib/debugobjects.c:1075
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&obj_hash[i].lock){-.-.}-{2:2}:
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
__debug_check_no_obj_freed lib/debugobjects.c:1034 [inline]
debug_check_no_obj_freed+0x9e/0x520 lib/debugobjects.c:1075
free_pages_prepare mm/page_alloc.c:1188 [inline]
__free_pages_ok+0x2e0/0xad0 mm/page_alloc.c:1312
free_large_kmalloc+0x101/0x1b0 mm/slab_common.c:984
trie_update_elem+0x783/0xd60 kernel/bpf/lpm_trie.c:443
bpf_map_update_value+0x64b/0x710 kernel/bpf/syscall.c:203
map_update_elem+0x586/0x710 kernel/bpf/syscall.c:1567
__sys_bpf+0x6b5/0x890 kernel/bpf/syscall.c:5466
__do_sys_bpf kernel/bpf/syscall.c:5582 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5580 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5580
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (&trie->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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
__bpf_prog_run include/linux/filter.h:617 [inline]
bpf_prog_run include/linux/filter.h:624 [inline]
bpf_prog_run_array include/linux/bpf.h:1994 [inline]
trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287
perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__free_object+0x3fe/0xa70 lib/debugobjects.c:371
__debug_check_no_obj_freed lib/debugobjects.c:1050 [inline]
debug_check_no_obj_freed+0x10e/0x520 lib/debugobjects.c:1075
slab_free_hook mm/slub.c:1786 [inline]
slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x290 mm/slub.c:3852
rcu_do_batch kernel/rcu/tree.c:2194 [inline]
rcu_core+0x9c1/0x17f0 kernel/rcu/tree.c:2467
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 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
native_irq_enable arch/x86/include/asm/irqflags.h:42 [inline]
arch_local_irq_enable arch/x86/include/asm/irqflags.h:99 [inline]
raw_spin_rq_unlock_irq kernel/sched/sched.h:1391 [inline]
finish_lock_switch kernel/sched/core.c:5136 [inline]
finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5254
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0x15b6/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
do_nanosleep+0x1b3/0x5e0 kernel/time/hrtimer.c:2095
hrtimer_nanosleep+0x175/0x370 kernel/time/hrtimer.c:2143
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1397 [inline]
__se_sys_clock_nanosleep+0x30f/0x3a0 kernel/time/posix-timers.c:1374
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&obj_hash[i].lock);
lock(&trie->lock);
lock(&obj_hash[i].lock);
lock(&trie->lock);
*** DEADLOCK ***
3 locks held by syz-executor/6811:
#0: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_do_batch kernel/rcu/tree.c:2188 [inline]
#0: ffffffff8d131ec0 (rcu_callback){....}-{0:0}, at: rcu_core+0x951/0x17f0 kernel/rcu/tree.c:2467
#1: ffffffff975b3140 (&obj_hash[i].lock){-.-.}-{2:2}, at: __debug_check_no_obj_freed lib/debugobjects.c:1034 [inline]
#1: ffffffff975b3140 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_check_no_obj_freed+0x9e/0x520 lib/debugobjects.c:1075
#2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#2: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: trace_call_bpf+0xc3/0x6c0 kernel/trace/bpf_trace.c:142
stack backtrace:
CPU: 0 PID: 6811 Comm: syz-executor Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
check_noncircular+0x2fc/0x400 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+0x37ef/0x7d80 kernel/locking/lockdep.c:5137
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xb4/0x100 kernel/locking/spinlock.c:162
trie_delete_elem+0x94/0x630 kernel/bpf/lpm_trie.c:466
bpf_prog_2c29ac5cdc6b1842+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1224 [inline]
__bpf_prog_run include/linux/filter.h:617 [inline]
bpf_prog_run include/linux/filter.h:624 [inline]
bpf_prog_run_array include/linux/bpf.h:1994 [inline]
trace_call_bpf+0x333/0x6c0 kernel/trace/bpf_trace.c:143
perf_trace_run_bpf_submit+0x7a/0x1c0 kernel/events/core.c:10287
perf_trace_lock_acquire+0x342/0x400 include/trace/events/lock.h:24
trace_lock_acquire include/trace/events/lock.h:24 [inline]
lock_acquire+0x3ef/0x420 kernel/locking/lockdep.c:5725
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
__free_object+0x3fe/0xa70 lib/debugobjects.c:371
__debug_check_no_obj_freed lib/debugobjects.c:1050 [inline]
debug_check_no_obj_freed+0x10e/0x520 lib/debugobjects.c:1075
slab_free_hook mm/slub.c:1786 [inline]
slab_free_freelist_hook+0xd2/0x1a0 mm/slub.c:1837
slab_free mm/slub.c:3830 [inline]
kmem_cache_free+0xf8/0x290 mm/slub.c:3852
rcu_do_batch kernel/rcu/tree.c:2194 [inline]
rcu_core+0x9c1/0x17f0 kernel/rcu/tree.c:2467
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 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:finish_task_switch+0x267/0x8f0 kernel/sched/core.c:5256
Code: 31 09 85 c0 0f 84 30 01 00 00 48 85 db 0f 85 4f 01 00 00 0f 1f 44 00 00 4c 89 e7 e8 23 f7 3a 09 e8 be 19 30 00 fb 4c 8b 65 b8 <49> 8d bc 24 00 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900038b79a0 EFLAGS: 00000286
RAX: 3340314815f13b00 RBX: 0000000000000000 RCX: 3340314815f13b00
RDX: dffffc0000000000 RSI: ffffffff8acacbe0 RDI: ffffffff8b1d32e0
RBP: ffffc900038b79f0 R08: ffffffff8e8c772f R09: 1ffffffff1d18ee5
R10: dffffc0000000000 R11: fffffbfff1d18ee6 R12: ffff88804c1ebc00
R13: 1ffff110171c79a9 R14: dffffc0000000000 R15: ffff8880b8e3cd48
context_switch kernel/sched/core.c:5385 [inline]
__schedule+0x15b6/0x4660 kernel/sched/core.c:6701
schedule+0xbd/0x170 kernel/sched/core.c:6775
do_nanosleep+0x1b3/0x5e0 kernel/time/hrtimer.c:2095
hrtimer_nanosleep+0x175/0x370 kernel/time/hrtimer.c:2143
__do_sys_clock_nanosleep kernel/time/posix-timers.c:1397 [inline]
__se_sys_clock_nanosleep+0x30f/0x3a0 kernel/time/posix-timers.c:1374
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc18cf5e90e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffd15fecb08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 000055558b189500 RCX: 00007fc18cf5e90e
RDX: 00007ffd15fecb60 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd15fecbcc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388
R13: 00000000000927c0 R14: 000000000006c356 R15: 00007ffd15fecc20
----------------
Code disassembly (best guess):
0: 31 09 xor %ecx,(%rcx)
2: 85 c0 test %eax,%eax
4: 0f 84 30 01 00 00 je 0x13a
a: 48 85 db test %rbx,%rbx
d: 0f 85 4f 01 00 00 jne 0x162
13: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
18: 4c 89 e7 mov %r12,%rdi
1b: e8 23 f7 3a 09 call 0x93af743
20: e8 be 19 30 00 call 0x3019e3
25: fb sti
26: 4c 8b 65 b8 mov -0x48(%rbp),%r12
* 2a: 49 8d bc 24 00 16 00 lea 0x1600(%r12),%rdi <-- trapping instruction
31: 00
32: 48 89 f8 mov %rdi,%rax
35: 48 c1 e8 03 shr $0x3,%rax
39: 42 0f b6 04 30 movzbl (%rax,%r14,1),%eax
3e: 84 c0 test %al,%al