[moderation] [bluetooth?] WARNING: refcount bug in sco_conn_del (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 40b055fe7f27 Add linux-next specific files for 20230712
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=17111190a80000
kernel config: https://syzkaller.appspot.com/x/.config?x=4ac50e88d62c9ae3
dashboard link: https://syzkaller.appspot.com/bug?extid=6686f5ece2ef713b7b61
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
CC: [johan....@gmail.com linux-b...@vger.kernel.org linux-...@vger.kernel.org luiz....@gmail.com mar...@holtmann.org net...@vger.kernel.org]

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4b4dc7732727/disk-40b055fe.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0e4c6e00f1a4/vmlinux-40b055fe.xz
kernel image: https://storage.googleapis.com/syzbot-assets/c3fd7f76d9de/bzImage-40b055fe.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+6686f5...@syzkaller.appspotmail.com

------------[ cut here ]------------
refcount_t: saturated; leaking memory.
WARNING: CPU: 1 PID: 7252 at lib/refcount.c:22 refcount_warn_saturate+0xd2/0x1f0 lib/refcount.c:22
Modules linked in:
CPU: 1 PID: 7252 Comm: syz-executor.2 Not tainted 6.5.0-rc1-next-20230712-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
RIP: 0010:refcount_warn_saturate+0xd2/0x1f0 lib/refcount.c:22
Code: 1d 94 03 7b 0a 31 ff 89 de e8 6a c0 6a fd 84 db 75 dc e8 31 c5 6a fd 48 c7 c7 e0 0c c8 8a c6 05 74 03 7b 0a 01 e8 2e d6 31 fd <0f> 0b eb c0 e8 15 c5 6a fd 0f b6 1d 60 03 7b 0a 31 ff 89 de e8 35
RSP: 0018:ffffc900043cfb08 EFLAGS: 00010282

RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff888022543b80 RSI: ffffffff814cde97 RDI: 0000000000000001
RBP: ffff88804487f080 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 000000000002e3d8 R12: ffff88807c2ea000
R13: 000000008b84e620 R14: ffff88807c2ea990 R15: ffff88807dcfc608
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556f24938 CR3: 0000000023d86000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__refcount_add include/linux/refcount.h:201 [inline]
__refcount_inc include/linux/refcount.h:250 [inline]
refcount_inc include/linux/refcount.h:267 [inline]
sock_hold include/net/sock.h:777 [inline]
sco_conn_del+0x256/0x2d0 net/bluetooth/sco.c:193
sco_disconn_cfm+0x76/0xb0 net/bluetooth/sco.c:1384
hci_disconn_cfm include/net/bluetooth/hci_core.h:1900 [inline]
hci_conn_hash_flush+0x114/0x230 net/bluetooth/hci_conn.c:2520
hci_dev_close_sync+0x5a7/0x10e0 net/bluetooth/hci_sync.c:5044
hci_dev_do_close+0x2e/0x70 net/bluetooth/hci_core.c:554
hci_unregister_dev+0x1e7/0x580 net/bluetooth/hci_core.c:2731
vhci_release+0x7f/0xf0 drivers/bluetooth/hci_vhci.c:669
__fput+0x3fd/0xac0 fs/file_table.c:384
task_work_run+0x14d/0x240 kernel/task_work.c:179
exit_task_work include/linux/task_work.h:38 [inline]
do_exit+0xa86/0x2a00 kernel/exit.c:874
do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
__do_sys_exit_group kernel/exit.c:1035 [inline]
__se_sys_exit_group kernel/exit.c:1033 [inline]
__x64_sys_exit_group+0x3e/0x50 kernel/exit.c:1033
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f576d67cb29
Code: Unable to access opcode bytes at 0x7f576d67caff.
RSP: 002b:00007ffd900e3a88 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f576d67cb29
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000043
RBP: 00007f576d6c844b R08: 00007ffd900e1826 R09: 00000000002759e7
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000000001c
R13: 00000000002759e7 R14: 0000000000275994 R15: 0000000000000006
</TASK>


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.