[v6.6] BUG: spinlock recursion in bpf_lru_push_free

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: cc1a1c5b404a Linux 6.6.103
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=12b62e62580000
kernel config: https://syzkaller.appspot.com/x/.config?x=412020841cf033b0
dashboard link: https://syzkaller.appspot.com/bug?extid=d9cabb2694119319e3cf
compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/182772cad8cb/disk-cc1a1c5b.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/9cf18a984bd5/vmlinux-cc1a1c5b.xz
kernel image: https://storage.googleapis.com/syzbot-assets/fd4621d0598e/bzImage-cc1a1c5b.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+d9cabb...@syzkaller.appspotmail.com

BUG: spinlock recursion on CPU#0, syz.6.1667/10564
lock: 0xffff88802f923340, .magic: dead4ead, .owner: syz.6.1667/10564, .owner_cpu: 0
CPU: 0 PID: 10564 Comm: syz.6.1667 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x16c/0x230 lib/dump_stack.c:106
spin_bug kernel/locking/spinlock_debug.c:77 [inline]
debug_spin_lock_before kernel/locking/spinlock_debug.c:86 [inline]
do_raw_spin_lock+0x1e7/0x2c0 kernel/locking/spinlock_debug.c:114
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:111 [inline]
_raw_spin_lock_irqsave+0xb4/0xf0 kernel/locking/spinlock.c:162
bpf_lru_list_push_free kernel/bpf/bpf_lru_list.c:318 [inline]
bpf_common_lru_push_free kernel/bpf/bpf_lru_list.c:538 [inline]
bpf_lru_push_free+0x1a6/0xb90 kernel/bpf/bpf_lru_list.c:561
htab_lru_map_delete_elem+0x55a/0x630 kernel/bpf/hashtab.c:1492
bpf_prog_f48a200a9ff6de76+0x42/0x65
bpf_dispatcher_nop_func include/linux/bpf.h:1213 [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_begin+0xdd/0x130 include/trace/events/lock.h:95
trace_contention_begin+0xe9/0x110 include/trace/events/lock.h:95
__pv_queued_spin_lock_slowpath+0xe0/0x9d0 kernel/locking/qspinlock.c:405
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]
lockdep_lock+0x17a/0x220 kernel/locking/lockdep.c:144
graph_lock kernel/locking/lockdep.c:170 [inline]
lookup_chain_cache_add kernel/locking/lockdep.c:3804 [inline]
validate_chain kernel/locking/lockdep.c:3837 [inline]
__lock_acquire+0x13ce/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
htab_lock_bucket+0x181/0x300 kernel/bpf/hashtab.c:166
htab_lru_map_delete_node+0x10f/0x750 kernel/bpf/hashtab.c:816
__bpf_lru_list_shrink_inactive kernel/bpf/bpf_lru_list.c:225 [inline]
__bpf_lru_list_shrink+0x1d5/0xc50 kernel/bpf/bpf_lru_list.c:271
bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:345 [inline]
bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:452 [inline]
bpf_lru_pop_free+0xfff/0x1cf0 kernel/bpf/bpf_lru_list.c:504
prealloc_lru_pop kernel/bpf/hashtab.c:304 [inline]
__htab_lru_percpu_map_update_elem+0x203/0x960 kernel/bpf/hashtab.c:1372
bpf_percpu_hash_update+0x119/0x200 kernel/bpf/hashtab.c:2416
bpf_map_update_value+0x3c3/0x720 kernel/bpf/syscall.c:175
generic_map_update_batch+0x5e0/0x810 kernel/bpf/syscall.c:1794
bpf_map_do_batch+0x3d7/0x610 kernel/bpf/syscall.c:5001
__sys_bpf+0x31b/0x800 kernel/bpf/syscall.c:-1
__do_sys_bpf kernel/bpf/syscall.c:5571 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5569 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5569
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: 0033:0x7f332f38ebe9
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:00007f33301fc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f332f5c5fa0 RCX: 00007f332f38ebe9
RDX: 0000000000000038 RSI: 0000200000000240 RDI: 000000000000001a
RBP: 00007f332f411e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f332f5c6038 R14: 00007f332f5c5fa0 R15: 00007ffda4a645e8
</TASK>


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