CVE-2026-68394

Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update

Published Aug 10, 2026 CVSS 3.1 · 7.8 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update

MGMT_OP_LOAD_CONN_PARAM queues conn_update_sync() when a single parameter
update changes an existing LE central connection. The queued work currently
stores a borrowed hci_conn_params entry from hdev->le_conn_params. A later
LOAD_CONN_PARAM request can clear disabled parameters and free that entry
before hci_cmd_sync_work() runs the queued callback.

Do not keep the borrowed hci_conn_params pointer in queued work. Queue the
hci_conn instead and hold a reference until the queued callback completes.
When the work runs, revalidate that the connection is still present, look
up the current hci_conn_params entry, and cancel the update if userspace
removed that entry while the work was pending.

Copy the interval values from the current params entry under hdev->lock,
then drop the lock and keep using hci_le_conn_update_sync() to issue the
update.

Validation reproduced this kernel report:
BUG: KASAN: slab-use-after-free in conn_update_sync+0x2a/0xf0 [bluetooth]
Read of size 1 at addr ffff88810c697126 by task kworker/u17:0/377
Workqueue: hci0 hci_cmd_sync_work [bluetooth]

Call Trace:
<TASK>
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x5f0
kasan_report+0xe0/0x110
conn_update_sync+0x2a/0xf0 [bluetooth]
hci_cmd_sync_work+0x187/0x210 [bluetooth]
process_one_work+0x4fd/0xbc0
worker_thread+0x2d8/0x570
kthread+0x1ad/0x1f0
ret_from_fork+0x3c9/0x540
ret_from_fork_asm+0x1a/0x30

Allocated by task 466:
hci_conn_params_add+0xa6/0x240 [bluetooth]
load_conn_param+0x4e1/0x850 [bluetooth]
hci_sock_sendmsg+0x96b/0xf80 [bluetooth]

Freed by task 474:
kfree+0x313/0x590
hci_conn_params_clear_disabled+0x9b/0xc0 [bluetooth]
load_conn_param+0x4bf/0x850 [bluetooth]
hci_sock_sendmsg+0x96b/0xf80 [bluetooth]

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-4745-1 linux-6.12 security update
Ubuntu USN Ubuntu USN USN-8887-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8889-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9003-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9043-1 Linux kernel (NVIDIA) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-416
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Weaknesses CWE-416
Type Values Removed Values Added
Weaknesses CWE-825
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.4, 'vector': 'CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H'}

threat_severity

Important

Type Values Removed Values Added
Weaknesses CWE-416
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update MGMT_OP_LOAD_CONN_PARAM queues conn_update_sync() when a single parameter update changes an existing LE central connection. The queued work currently stores a borrowed hci_conn_params entry from hdev->le_conn_params. A later LOAD_CONN_PARAM request can clear disabled parameters and free that entry before hci_cmd_sync_work() runs the queued callback. Do not keep the borrowed hci_conn_params pointer in queued work. Queue the hci_conn instead and hold a reference until the queued callback completes. When the work runs, revalidate that the connection is still present, look up the current hci_conn_params entry, and cancel the update if userspace removed that entry while the work was pending. Copy the interval values from the current params entry under hdev->lock, then drop the lock and keep using hci_le_conn_update_sync() to issue the update. Validation reproduced this kernel report: BUG: KASAN: slab-use-after-free in conn_update_sync+0x2a/0xf0 [bluetooth] Read of size 1 at addr ffff88810c697126 by task kworker/u17:0/377 Workqueue: hci0 hci_cmd_sync_work [bluetooth] Call Trace: <TASK> dump_stack_lvl+0x66/0xa0 print_report+0xce/0x5f0 kasan_report+0xe0/0x110 conn_update_sync+0x2a/0xf0 [bluetooth] hci_cmd_sync_work+0x187/0x210 [bluetooth] process_one_work+0x4fd/0xbc0 worker_thread+0x2d8/0x570 kthread+0x1ad/0x1f0 ret_from_fork+0x3c9/0x540 ret_from_fork_asm+0x1a/0x30 Allocated by task 466: hci_conn_params_add+0xa6/0x240 [bluetooth] load_conn_param+0x4e1/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth] Freed by task 474: kfree+0x313/0x590 hci_conn_params_clear_disabled+0x9b/0xc0 [bluetooth] load_conn_param+0x4bf/0x850 [bluetooth] hci_sock_sendmsg+0x96b/0xf80 [bluetooth]
Title Bluetooth: MGMT: revalidate LOAD_CONN_PARAM queued update
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 19, 2026, 9:09 PM
Reserved
Jul 30, 2026, 9:28 AM
Status
Received
Published
Aug 10, 2026, 1:20 PM
Modified
Oct 19, 2026, 10:17 PM
Severity
Important
Public date
Aug 10, 2026, 12:04 PM