============================================
WARNING: possible recursive locking detected
syzkaller #0 Not tainted
--------------------------------------------
kworker/1:8/10145 is trying to acquire lock:
ffff8880253e0218 (&qs->lock){-.-.}-{2:2}, at: __queue_map_get+0x11c/0x4b0 kernel/bpf/queue_stack_maps.c:105
but task is already holding lock:
ffff88807a6de218 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x11e/0x450 kernel/bpf/queue_stack_maps.c:140
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&qs->lock);
lock(&qs->lock);
*** DEADLOCK ***
May be due to missing lock nesting notation
7 locks held by kworker/1:8/10145:
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#0: ffff888017870938 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#1: ffffc90003867d00 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:2609 [inline]
#1: ffffc90003867d00 ((work_completion)(&w->work)#2){+.+.}-{0:0}, at: process_scheduled_works+0x957/0x15b0 kernel/workqueue.c:2711
#2: ffffffff8e024848 (nf_conntrack_mutex){+.+.}-{3:3}, at: nf_ct_iterate_cleanup+0x3f/0x510 net/netfilter/nf_conntrack_core.c:2429
#3: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __run_hrtimer kernel/time/hrtimer.c:1754 [inline]
#3: ffff8880b8f2b718 (hrtimer_bases.lock){-.-.}-{2:2}, at: __hrtimer_run_queues+0x5e3/0xc40 kernel/time/hrtimer.c:1814
#4: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#4: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#4: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
#4: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361
#5: ffff88807a6de218 (&qs->lock){-.-.}-{2:2}, at: __stack_map_get+0x11e/0x450 kernel/bpf/queue_stack_maps.c:140
#6: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#6: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#6: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2321 [inline]
#6: ffffffff8cd2ff20 (rcu_read_lock){....}-{1:2}, at: bpf_trace_run2+0xde/0x3c0 kernel/trace/bpf_trace.c:2361
stack backtrace:
CPU: 1 PID: 10145 Comm: kworker/1:8 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events iterate_cleanup_work
Call Trace:
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
check_deadlock kernel/locking/lockdep.c:3062 [inline]
validate_chain kernel/locking/lockdep.c:3856 [inline]
__lock_acquire+0x5d40/0x7c80 kernel/locking/lockdep.c:5137
lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
_raw_spin_lock_irqsave+0xa8/0xf0 kernel/locking/spinlock.c:162
__queue_map_get+0x11c/0x4b0 kernel/bpf/queue_stack_maps.c:105
bpf_prog_00798911c748094f+0x42/0x46
bpf_dispatcher_nop_func include/linux/bpf.h:1224 [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_contention_end+0xdd/0x130 include/trace/events/lock.h:122
trace_contention_end+0xe6/0x110 include/trace/events/lock.h:122
__pv_queued_spin_lock_slowpath+0x7ec/0x9d0 kernel/locking/qspinlock.c:560
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x24e/0x2c0 kernel/locking/spinlock_debug.c:115
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
_raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162
__stack_map_get+0x11e/0x450 kernel/bpf/queue_stack_maps.c:140
bpf_prog_94b194d4ebfffdd5+0x45/0x49
bpf_dispatcher_nop_func include/linux/bpf.h:1224 [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+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x17/0x80 kernel/kcov.c:320
Code: 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d b0 20 7e 7e 65 8b 15 b1 20 7e 7e <81> e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 57 83 b9 1c 16 00 00
RSP: 0018:ffffc90003867a68 EFLAGS: 00000246
RAX: ffffffff88a5255d RBX: ffffc90003867b20 RCX: ffff888020df0000
RDX: 0000000080000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 000000000002a449 R08: ffffffff90d94587 R09: 1ffffffff21b28b0
R10: dffffc0000000000 R11: fffffbfff21b28b1 R12: 1ffff11005895224
R13: ffff88802c4a9120 R14: dffffc0000000000 R15: 1ffff9200070cf64
get_next_corpse net/netfilter/nf_conntrack_core.c:2379 [inline]
nf_ct_iterate_cleanup+0xfd/0x510 net/netfilter/nf_conntrack_core.c:2430
iterate_cleanup_work+0xdc/0x1f0 net/netfilter/nf_nat_masquerade.c:87
process_one_work kernel/workqueue.c:2634 [inline]
process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
----------------
Code disassembly (best guess):
0: 48 89 44 11 20 mov %rax,0x20(%rcx,%rdx,1)
5: c3 ret
6: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
d: 00 00 00
10: 0f 1f 00 nopl (%rax)
13: f3 0f 1e fa endbr64
17: 48 8b 04 24 mov (%rsp),%rax
1b: 65 48 8b 0d b0 20 7e mov %gs:0x7e7e20b0(%rip),%rcx # 0x7e7e20d3
22: 7e
23: 65 8b 15 b1 20 7e 7e mov %gs:0x7e7e20b1(%rip),%edx # 0x7e7e20db
* 2a: 81 e2 00 01 ff 00 and $0xff0100,%edx <-- trapping instruction
30: 74 11 je 0x43
32: 81 fa 00 01 00 00 cmp $0x100,%edx
38: 75 57 jne 0x91
3a: 83 .byte 0x83
3b: b9 1c 16 00 00 mov $0x161c,%ecx