In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: HIDP: reject frames without a transaction header
hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0]
before checking that the L2CAP SDU contains a transaction header. A
connected HIDP peer can send an empty basic-mode SDU and make both paths
use an uninitialized byte from skb tailroom.
KMSAN reports the use in hidp_session_run(), with the uninitialized value
originating in __alloc_skb() through vhci_write(). The control path
produces two reports and the interrupt path produces one.
The byte can also be controlled by a malformed lower-layer packet. If an
HCI ACL packet contains an L2CAP PDU with a declared zero-length payload
followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to
the declared PDU length before dispatch. The current HIDP path nevertheless
consumes the extra byte as HIDP_TRANS_HID_CONTROL |
HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this
change, the same packet is discarded and a subsequent feature report
request succeeds.
Pull the transaction header with skb_pull_data() and discard frames that
do not contain it.
Bluetooth: HIDP: reject frames without a transaction header
hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0]
before checking that the L2CAP SDU contains a transaction header. A
connected HIDP peer can send an empty basic-mode SDU and make both paths
use an uninitialized byte from skb tailroom.
KMSAN reports the use in hidp_session_run(), with the uninitialized value
originating in __alloc_skb() through vhci_write(). The control path
produces two reports and the interrupt path produces one.
The byte can also be controlled by a malformed lower-layer packet. If an
HCI ACL packet contains an L2CAP PDU with a declared zero-length payload
followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to
the declared PDU length before dispatch. The current HIDP path nevertheless
consumes the extra byte as HIDP_TRANS_HID_CONTROL |
HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this
change, the same packet is discarded and a subsequent feature report
request succeeds.
Pull the transaction header with skb_pull_data() and discard frames that
do not contain it.
Metrics
Affected Vendors & Products
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Sat, 15 Aug 2026 12:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: Bluetooth: HIDP: reject frames without a transaction header hidp_recv_ctrl_frame() and hidp_recv_intr_frame() read skb->data[0] before checking that the L2CAP SDU contains a transaction header. A connected HIDP peer can send an empty basic-mode SDU and make both paths use an uninitialized byte from skb tailroom. KMSAN reports the use in hidp_session_run(), with the uninitialized value originating in __alloc_skb() through vhci_write(). The control path produces two reports and the interrupt path produces one. The byte can also be controlled by a malformed lower-layer packet. If an HCI ACL packet contains an L2CAP PDU with a declared zero-length payload followed by an extra 0x15 byte, l2cap_recv_acldata() reduces skb->len to the declared PDU length before dispatch. The current HIDP path nevertheless consumes the extra byte as HIDP_TRANS_HID_CONTROL | HIDP_CTRL_VIRTUAL_CABLE_UNPLUG and terminates the HIDP session. With this change, the same packet is discarded and a subsequent feature report request succeeds. Pull the transaction header with skb_pull_data() and discard frames that do not contain it. | |
| Title | Bluetooth: HIDP: reject frames without a transaction header | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
|
Projects
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-08-15T12:27:31.288Z
Reserved: 2026-08-15T05:44:03.908Z
Link: CVE-2026-74508
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.