Copyright © 2012 Red Hat, Inc. All rights reserved. Moderate 2026-07-29T00:00:00 kernel: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() 7.0 CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H CWE-825

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix use-after-free in l2cap_sock_new_connection_cb() l2cap_sock_new_connection_cb() returned l2cap_pi(sk)->chan after release_sock(parent). Once the parent lock is dropped the newly enqueued child socket sk is reachable via the accept queue, so another task can accept and free it before the callback dereferences sk, resulting in a use-after-free. Rework the ->new_connection() op so the core, rather than the callback, owns the child channel's lifetime. The op now receives a pre-allocated new_chan and returns an errno instead of allocating and returning a channel. l2cap_new_connection() allocates the child channel and links it into the conn list via __l2cap_chan_add() before invoking the callback, so the conn-list reference keeps the channel alive once release_sock(parent) exposes the socket to other tasks. Channel configuration that was duplicated in l2cap_sock_init() and the various new_connection callbacks is consolidated into l2cap_chan_set_defaults(), which now inherits from the parent channel when one is supplied.

A flaw was found in the Linux kernel's Bluetooth L2CAP component. A race condition exists during the handling of new Bluetooth connections, where a newly created socket can be prematurely freed by another process before a callback function completes its operation. This use-after-free vulnerability could allow a local attacker to potentially execute arbitrary code or cause a system crash (Denial of Service).

Red Hat Enterprise Linux 10 Affected kernel Red Hat Enterprise Linux 6 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel Red Hat Enterprise Linux 7 Not affected kernel-rt Red Hat Enterprise Linux 8 Affected kernel Red Hat Enterprise Linux 8 Affected kernel-rt Red Hat Enterprise Linux 9 Affected kernel Red Hat Enterprise Linux 9 Affected kernel-rt https://www.cve.org/CVERecord?id=CVE-2026-64557 https://nvd.nist.gov/vuln/detail/CVE-2026-64557 https://lore.kernel.org/linux-cve-announce/2026072941-CVE-2026-64557-4d87@gregkh/T