Race condition on shared HCI TX descriptor in the Infineon PSOC 6 BLESS Bluetooth driver can leak adjacent memory over the air
Summary
| CVE | CVE-2026-78117 |
|---|---|
| State | PUBLISHED |
| Assigner | zephyr |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-21 19:17:03 UTC |
| Updated | 2026-10-21 19:17:03 UTC |
| Description | The Infineon PSOC 6 BLESS HCI driver in drivers/bluetooth/hci/hci_infineon_psoc6_bless.c stored the outgoing HCI packet descriptor in a file-scope variable, static cy_stc_ble_hci_tx_packet_info_t hci_tx_pkt. psoc6_bless_send() cleared and populated that descriptor's packetType, dataLength and data fields before acquiring psoc6_bless_operation_sem, so the driver's serialising semaphore protected only the call into Cy_BLE_SoftHciSendAppPkt() and not the shared state that call reads. The Bluetooth host does not guarantee a single HCI sender. Most transmissions are funnelled through the cooperative TX-processor work queue, but bt_hci_cmd_send() deliberately bypasses bt_dev.cmd_tx_queue for BT_HCI_OP_HOST_NUM_COMPLETED_PACKETS and calls bt_send() directly from the caller's thread; that caller is bt_hci_host_num_completed_packets(), the acl_in_pool destroy callback, which runs on whichever thread drops the last reference to a received ACL buffer. CONFIG_BT_HCI_ACL_FLOW_CONTROL defaults to y on this driver's boards, and an application that returns -EINPROGRESS from its L2CAP recv callback and later calls bt_l2cap_chan_recv_complete() performs that unref from its own preemptible thread. A remote peer that generates Bluetooth traffic concurrently with the device's own transmissions raises the collision rate. When two senders interleave, the semaphore holder can hand the controller a descriptor whose dataLength comes from one net_buf and whose data pointer comes from another — or one whose buffer has already been returned to its pool. The controller then copies and transmits up to a full HCI/ACL payload starting at a shorter or recycled buffer, disclosing adjacent RAM contents to the connected peer; other interleavings duplicate one HCI packet and silently drop another, disrupting the link. The driver only reads through the shared descriptor, so no memory corruption or write primitive results, and the disclosed bytes are not attacker-chosen. The fix makes the descriptor a local variable in psoc6_bless_send(), removing the shared state; Cy_BLE_SoftHciSendAppPkt() copies the packet before returning, so it need not outlive the call. |
Risk And Classification
Primary CVSS: v3.1 4.2 MEDIUM from [email protected]
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Problem Types: CWE-362 | CWE-362 race
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 4.2 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
| 3.1 | CNA | CVSS | 4.2 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
NoneAvailability
LowCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:L
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zephyrproject | Zephyr | affected 3.4.0 4.4.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/zephyrproject-rtos/zephyr/commit/7d0efa35134141bb1b1527f9078d... | [email protected] | github.com | |
| github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-7v9c-hmjh-... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.