------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 6129 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 6129 Comm: kbnepd bnep0 Not tainted 6.14.0-next-20250404-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Code: a0 94 a1 8c e8 67 75 7c fc 90 0f 0b 90 90 eb 99 e8 1b 55 bd fc c6 05 21 e9 43 0b 01 90 48 c7 c7 00 95 a1 8c e8 47 75 7c fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 f8 54 bd fc c6 05 fb e8 43 0b 01 90
RSP: 0018:ffffc90003307700 EFLAGS: 00010246
RAX: 25ce8e209681a800 RBX: ffff8880315bd478 RCX: ffff88801e799e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81828012 R09: fffffbfff1d7a980
R10: dffffc0000000000 R11: fffffbfff1d7a980 R12: ffff8880315bd460
R13: 1ffff110062b7a8c R14: ffff8880315bd460 R15: ffffffff8650b640
FS:  0000000000000000(0000) GS:ffff888124f8f000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f778fb5b290 CR3: 0000000032116000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:400 [inline]
 __refcount_dec_and_test include/linux/refcount.h:432 [inline]
 refcount_dec_and_test include/linux/refcount.h:450 [inline]
 kref_put include/linux/kref.h:64 [inline]
 klist_dec_and_del+0x3ec/0x3f0 lib/klist.c:206
 klist_put lib/klist.c:217 [inline]
 klist_del+0xa7/0x110 lib/klist.c:230
 device_del+0x2cb/0x9b0 drivers/base/core.c:3832
 unregister_netdevice_many_notify+0x1f37/0x2510 net/core/dev.c:12011
 unregister_netdevice_many net/core/dev.c:12039 [inline]
 unregister_netdevice_queue+0x383/0x400 net/core/dev.c:11891
 unregister_netdevice include/linux/netdevice.h:3374 [inline]
 unregister_netdev+0x1f/0x60 net/core/dev.c:12057
 bnep_session+0x2e52/0x3050 net/bluetooth/bnep/core.c:525
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>