Description
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: hci_sync: Protect UUID list traversal
The hci_sync conversion moved class-of-device and EIR generation from an
HCI request built under hdev->lock to asynchronous command sync work.
The worker holds hdev->req_lock, but that lock does not serialize access
to hdev->uuids against add_uuid() and remove_uuid(), which update the
list under hdev->lock.
The following interleaving can therefore occur:
CPU0 (command sync work) CPU1 (management socket)
fetch uuid from the list
list_del(&uuid->list)
kfree(uuid)
read uuid->size
KASAN reports the resulting use-after-free:
BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0
Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
eir_create+0xb8f/0xee0
hci_update_eir_sync+0x1c0/0x330
hci_cmd_sync_work+0x13c/0x290
process_one_work+0x63a/0x1070
worker_thread+0x45b/0xd10
Allocated by task 86:
__kasan_kmalloc+0x8f/0xa0
add_uuid+0x18a/0x4b0
hci_sock_sendmsg+0x1033/0x1ea0
Freed by task 92:
__kasan_slab_free+0x43/0x70
kfree+0x131/0x3c0
remove_uuid+0x25e/0x560
hci_sock_sendmsg+0x1033/0x1ea0
Hold hdev->lock while generating and committing the class-of-device and
EIR snapshots. Release it before sending an HCI command, so controller
waits do not happen under the device lock. This protects all UUID list
walks in these paths and restores the serialization lost in the command
sync conversion.
Bluetooth: hci_sync: Protect UUID list traversal
The hci_sync conversion moved class-of-device and EIR generation from an
HCI request built under hdev->lock to asynchronous command sync work.
The worker holds hdev->req_lock, but that lock does not serialize access
to hdev->uuids against add_uuid() and remove_uuid(), which update the
list under hdev->lock.
The following interleaving can therefore occur:
CPU0 (command sync work) CPU1 (management socket)
fetch uuid from the list
list_del(&uuid->list)
kfree(uuid)
read uuid->size
KASAN reports the resulting use-after-free:
BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0
Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87
Workqueue: hci0 hci_cmd_sync_work
Call Trace:
eir_create+0xb8f/0xee0
hci_update_eir_sync+0x1c0/0x330
hci_cmd_sync_work+0x13c/0x290
process_one_work+0x63a/0x1070
worker_thread+0x45b/0xd10
Allocated by task 86:
__kasan_kmalloc+0x8f/0xa0
add_uuid+0x18a/0x4b0
hci_sock_sendmsg+0x1033/0x1ea0
Freed by task 92:
__kasan_slab_free+0x43/0x70
kfree+0x131/0x3c0
remove_uuid+0x25e/0x560
hci_sock_sendmsg+0x1033/0x1ea0
Hold hdev->lock while generating and committing the class-of-device and
EIR snapshots. Release it before sending an HCI command, so controller
waits do not happen under the device lock. This protects all UUID list
walks in these paths and restores the serialization lost in the command
sync conversion.
Published:
2026-08-10
Score:
n/a
EPSS:
n/a
KEV:
No
Impact:
n/a
Action:
n/a
No analysis available yet.
Remediation
No remediation available yet.
Tracking
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Advisories
No advisories yet.
References
History
Mon, 10 Aug 2026 12:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_sync: Protect UUID list traversal The hci_sync conversion moved class-of-device and EIR generation from an HCI request built under hdev->lock to asynchronous command sync work. The worker holds hdev->req_lock, but that lock does not serialize access to hdev->uuids against add_uuid() and remove_uuid(), which update the list under hdev->lock. The following interleaving can therefore occur: CPU0 (command sync work) CPU1 (management socket) fetch uuid from the list list_del(&uuid->list) kfree(uuid) read uuid->size KASAN reports the resulting use-after-free: BUG: KASAN: slab-use-after-free in eir_create+0xb8f/0xee0 Read of size 1 at addr ffff88810dbd8620 by task kworker/u17:0/87 Workqueue: hci0 hci_cmd_sync_work Call Trace: eir_create+0xb8f/0xee0 hci_update_eir_sync+0x1c0/0x330 hci_cmd_sync_work+0x13c/0x290 process_one_work+0x63a/0x1070 worker_thread+0x45b/0xd10 Allocated by task 86: __kasan_kmalloc+0x8f/0xa0 add_uuid+0x18a/0x4b0 hci_sock_sendmsg+0x1033/0x1ea0 Freed by task 92: __kasan_slab_free+0x43/0x70 kfree+0x131/0x3c0 remove_uuid+0x25e/0x560 hci_sock_sendmsg+0x1033/0x1ea0 Hold hdev->lock while generating and committing the class-of-device and EIR snapshots. Release it before sending an HCI command, so controller waits do not happen under the device lock. This protects all UUID list walks in these paths and restores the serialization lost in the command sync conversion. | |
| Title | Bluetooth: hci_sync: Protect UUID list traversal | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-10T12:00:01.711Z
Reserved: 2026-07-30T09:28:09.373Z
Link: CVE-2026-68189
No data.
No data.
No data.
OpenCVE Enrichment
Updated: 2026-08-10T17:15:02Z
Weaknesses
No weakness.