------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 7419 at lib/refcount.c:28 refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 7419 Comm: kbnepd  Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28
Code: 80 b3 e2 8b e8 07 2b bb fc 90 0f 0b 90 90 eb d7 e8 eb 8e f7 fc c6 05 d8 69 c5 0a 01 90 48 c7 c7 e0 b3 e2 8b e8 e7 2a bb fc 90 <0f> 0b 90 90 eb b7 e8 cb 8e f7 fc c6 05 b5 69 c5 0a 01 90 48 c7 c7
RSP: 0018:ffffc9000cf2f700 EFLAGS: 00010246
RAX: 7cad88b0cb87bd00 RBX: 0000000000000003 RCX: ffff8880321a1e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffff8880b8624253 R09: 1ffff110170c484a
R10: dffffc0000000000 R11: ffffed10170c484b R12: dffffc0000000000
R13: ffff88806d927060 R14: ffff88806d927078 R15: ffffffff86002eb0
FS:  0000000000000000(0000) GS:ffff888125c18000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffc4a7c11d8 CR3: 0000000078ae4000 CR4: 00000000003526f0
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+0x3c7/0x3d0 lib/klist.c:206
 klist_put lib/klist.c:217 [inline]
 klist_del+0xa6/0x110 lib/klist.c:230
 device_del+0x280/0x8e0 drivers/base/core.c:3855
 unregister_netdevice_many_notify+0x1a6b/0x1ff0 net/core/dev.c:12201
 unregister_netdevice_many net/core/dev.c:12229 [inline]
 unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12073
 unregister_netdevice include/linux/netdevice.h:3385 [inline]
 unregister_netdev+0x1f/0x60 net/core/dev.c:12247
 bnep_session+0x294d/0x2b40 net/bluetooth/bnep/core.c:525
 kthread+0x70e/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>