CVE-2026-31408
Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SCO: Fix use-after-free in sco_recv_frame() due to missing sock_hold
sco_recv_frame() reads conn->sk under sco_conn_lock() but immediately releases the lock without holding a reference to the socket. A concurrent close() can free the socket between the lock release and the subsequent sk->sk_state access, resulting in a use-after-free.
Other functions in the same file (sco_sock_timeout(), sco_conn_del()) correctly use sco_sock_hold() to safely hold a reference under the lock.
Fix by using sco_sock_hold() to take a reference before releasing the lock, and adding sock_put() on all exit paths.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A use-after-free in Linux Bluetooth SCO layer lets local attackers crash the kernel or possibly execute code via a race condition.
Vulnerability
Overview
In the Linux kernel's Bluetooth SCO component, sco_recv_frame() reads the socket pointer conn->sk while holding sco_conn_lock(), but releases the lock before using the socket to check sk->sk_state. If a concurrent close() call frees the socket between the lock release and the state read, the kernel accesses freed memory, leading to a use-after-free bug [1][2][3][4].
Exploitation
Conditions
An attacker must be able to trigger a SCO (Synchronous Connection-Oriented) connection and simultaneously close the associated socket, creating a race window. Local access to Bluetooth functionality is required, but no special privileges beyond the ability to open and close BT sockets are needed [1].
Impact
Successful exploitation can cause a kernel crash (denial of service) or, if the freed memory is reallocated with attacker-controlled data, potentially lead to arbitrary code execution in the kernel context, compromising the entire system [1].
Mitigation
The Linux kernel developers fixed the issue by adding a sco_sock_hold() call to take a reference on the socket before dropping the lock, with corresponding sock_put() calls on all exit paths. Patches are available in the stable kernel trees [2][3][4]. System administrators should apply the latest kernel updates to protect against this vulnerability.
AI Insight generated on May 18, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
7- git.kernel.org/stable/c/108b81514d8f2535eb16651495cefb2250528db3nvd
- git.kernel.org/stable/c/45aaca995e4a7a05b272a58e7ab2fff4f611b8f1nvd
- git.kernel.org/stable/c/598dbba9919c5e36c54fe1709b557d64120cb94bnvd
- git.kernel.org/stable/c/7197462e90b8ce15caa1ae15d4bc2bb8cd21b11envd
- git.kernel.org/stable/c/b0a7da0e3f7442545f071499beb36374714bb9denvd
- git.kernel.org/stable/c/d57384e27d1ebf0047e3f00a6e1181b8be9857a2nvd
- git.kernel.org/stable/c/e76e8f0581ef555eacc11dbb095e602fb30a5361nvd
News mentions
0No linked articles in our index yet.