------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 10056 at lib/refcount.c:28 refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Modules linked in:
CPU: 0 UID: 0 PID: 10056 Comm: kbnepd bnep0 Not tainted 6.13.0-rc5-syzkaller-00163-gab75170520d4 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:refcount_warn_saturate+0x14a/0x210 lib/refcount.c:28
Code: ff 89 de e8 88 f9 f9 fc 84 db 0f 85 66 ff ff ff e8 9b f7 f9 fc c6 05 ab c9 a7 0b 01 90 48 c7 c7 e0 9a d1 8b e8 17 31 ba fc 90 <0f> 0b 90 90 e9 43 ff ff ff e8 78 f7 f9 fc 0f b6 1d 86 c9 a7 0b 31
RSP: 0018:ffffc90003e9f9a8 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff815a5139
RDX: ffff88805135c880 RSI: ffffffff815a5146 RDI: 0000000000000001
RBP: ffff88804baa9078 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000003 R12: ffff88805011d800
R13: ffff88804baa9078 R14: ffffffff85c4f170 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f849fa8c870 CR3: 000000000df7e000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 000000000000000a DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __refcount_sub_and_test include/linux/refcount.h:275 [inline]
 __refcount_dec_and_test include/linux/refcount.h:307 [inline]
 refcount_dec_and_test include/linux/refcount.h:325 [inline]
 kref_put include/linux/kref.h:64 [inline]
 klist_dec_and_del lib/klist.c:206 [inline]
 klist_put+0x11b/0x1b0 lib/klist.c:217
 device_del+0x1d9/0x9f0 drivers/base/core.c:3831
 unregister_netdevice_many_notify+0x105d/0x1e60 net/core/dev.c:11564
 unregister_netdevice_many net/core/dev.c:11592 [inline]
 unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11464
 unregister_netdevice include/linux/netdevice.h:3192 [inline]
 unregister_netdev+0x1c/0x30 net/core/dev.c:11610
 bnep_session+0x21b6/0x2ca0 net/bluetooth/bnep/core.c:525
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>