------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 1 PID: 9543 at lib/refcount.c:28 refcount_warn_saturate+0x15a/0x1d0 lib/refcount.c:28
Modules linked in:
CPU: 1 UID: 0 PID: 9543 Comm: kbnepd bnep0 Not tainted 6.14.0-rc4-syzkaller-01091-gf252f23ab657 #0
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 a3 80 8c e8 c7 3e 8c fc 90 0f 0b 90 90 eb 99 e8 5b 82 cc fc c6 05 c8 de 31 0b 01 90 48 c7 c7 00 a4 80 8c e8 a7 3e 8c fc 90 <0f> 0b 90 90 e9 76 ff ff ff e8 38 82 cc fc c6 05 a2 de 31 0b 01 90
RSP: 0018:ffffc9000ba0f720 EFLAGS: 00010246
RAX: 7f935932fc317700 RBX: ffff888052b36c78 RCX: ffff888030209e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffffffff81817e32 R09: fffffbfff1d3a614
R10: dffffc0000000000 R11: fffffbfff1d3a614 R12: ffff888052b36c60
R13: 1ffff1100a566d8c R14: ffff888052b36c60 R15: ffffffff86387ee0
FS:  0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f69478d7d60 CR3: 000000000e938000 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: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+0x3ec/0x3f0 lib/klist.c:206
 klist_put lib/klist.c:217 [inline]
 klist_del+0xa7/0x110 lib/klist.c:230
 device_del+0x2c9/0x9b0 drivers/base/core.c:3831
 unregister_netdevice_many_notify+0x1ae7/0x2070 net/core/dev.c:12075
 unregister_netdevice_many net/core/dev.c:12103 [inline]
 unregister_netdevice_queue+0x303/0x370 net/core/dev.c:11960
 unregister_netdevice include/linux/netdevice.h:3367 [inline]
 unregister_netdev+0x1f/0x60 net/core/dev.c:12121
 bnep_session+0x2e4e/0x3040 net/bluetooth/bnep/core.c:525
 kthread+0x7a9/0x920 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>