CVE-2026-98456

Bluetooth: mgmt: fix race in read_unconf_index_list()

Published Oct 18, 2026 CVSS 3.1 · 7 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: mgmt: fix race in read_unconf_index_list()

read_unconf_index_list() counts unconfigured controllers before allocating
its response, then checks the device flags again while filling it.

hci_dev_list_lock stabilizes list membership, but it does not serialize the
per-device flags. During asynchronous controller setup, the worker can set
HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller
omitted from the allocation count can then become eligible for the fill
pass, causing an out-of-bounds write to rp->index[].

Allocate space for every device on hci_dev_list. Since list membership
cannot change while hci_dev_list_lock is held, the response remains large
enough regardless of flag transitions. The reported count and response
length still include only eligible unconfigured controllers.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4850-1 linux-6.12 security update
Ubuntu USN Ubuntu USN USN-9019-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9020-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9022-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9023-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9024-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9025-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9026-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-9039-1 Linux kernel (Azure CVM) vulnerabilities
Ubuntu USN Ubuntu USN USN-9040-1 Linux kernel (Low Latency NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9066-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-9091-1 Linux kernel (NVIDIA Tegra) vulnerabilities
History
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 4.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses CWE-122
CWE-823
Type Values Removed Values Added
Weaknesses CWE-787
References
Metrics threat_severity

None

cvssV3_1

{'score': 4.1, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Type Values Removed Values Added
Weaknesses CWE-122
CWE-823
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: mgmt: fix race in read_unconf_index_list() read_unconf_index_list() counts unconfigured controllers before allocating its response, then checks the device flags again while filling it. hci_dev_list_lock stabilizes list membership, but it does not serialize the per-device flags. During asynchronous controller setup, the worker can set HCI_UNCONFIGURED and clear HCI_SETUP between the two passes. A controller omitted from the allocation count can then become eligible for the fill pass, causing an out-of-bounds write to rp->index[]. Allocate space for every device on hci_dev_list. Since list membership cannot change while hci_dev_list_lock is held, the response remains large enough regardless of flag transitions. The reported count and response length still include only eligible unconfigured controllers.
Title Bluetooth: mgmt: fix race in read_unconf_index_list()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Oct 30, 2026, 12:38 PM
Reserved
Sep 25, 2026, 10:25 AM
Status
Received
Published
Oct 18, 2026, 4:16 PM
Modified
Oct 30, 2026, 1:21 PM
Severity
Moderate
Public date
Oct 18, 2026, 12:00 AM