Bug 2507293 (CVE-2026-64406)

Summary:	CVE-2026-64406 kernel: Bluetooth: fix UAF in bt_accept_dequeue()
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's Bluetooth subsystem. This use-after-free (UAF) vulnerability in the `bt_accept_dequeue()` function occurs because a temporary reference is prematurely dropped, leading to `sock_hold()` accessing freed memory. An attacker could potentially exploit this to cause a denial of service (DoS) or other unpredictable system behavior.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-25 10:14:56 UTC

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: fix UAF in bt_accept_dequeue()

bt_accept_get() takes a temporary reference before dropping the accept
queue lock. bt_accept_dequeue() currently drops that reference before
bt_accept_unlink(), leaving only the queue reference.

bt_accept_unlink() drops the queue reference. The subsequent
sock_hold() therefore accesses freed memory if it was the final
reference, as observed by KASAN during listening L2CAP socket cleanup.

Retain the temporary queue-walk reference through unlink and hand it to
the caller on success. Drop it explicitly on the closed and
not-yet-connected paths.

Comment 1 TEJ RATHI 2026-07-27 06:55:32 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026072531-CVE-2026-64406-daf2@gregkh/T