CVE-2023-54038 Bluetooth: hci_conn: return ERR_PTR instead of NULL when there is no link
A null pointer dereference in the Linux kernel Bluetooth subsystem allows local attackers to cause a system crash via crafted Bluetooth connections.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2023-54038?
CVE-2023-54038 is a vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_conn: return ERR_PTR instead of NULL when there is no link
hci_connect_sco currently returns NULL when there is no link (i.e. when hci_conn_link() returns NULL).
sco_connect() expects an ERR_PTR in case of any error (see line 266 in sco.c). Thus, hcon set as NULL passes through to sco_conn_add(), which tries to get hcon->hdev, resulting in dereferencing a NULL pointer as reported by syzkaller.
The same issue exists for iso_connect_cis() calling hci_connect_cis().
Thus, make hci_connect_sco() and hci_connect_cis() return ERR_PTR instead of NULL.
Which versions are affected by CVE-2023-54038?
How do I fix CVE-2023-54038?
Apply the vendor's patch.
Is CVE-2023-54038 being exploited?
There is no known exploitation of CVE-2023-54038 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2023-54038, DEBIAN-CVE-2023-54038, GHSA-j568-pqpx-g2wf, UBUNTU-CVE-2023-54038.