Bluetooth: btintel_pcie: validate device-supplied DMA indices

Overview

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: btintel_pcie: validate device-supplied DMA indices

In btintel_pcie_msix_rx_handle(), the driver processes RX completion descriptors (urbd1) written by the PCIe device into DMA-coherent memory. urbd1->frbd_tag (a 16-bit field fully controlled by the device firmware via DMA) is used directly as an array index into rxq->bufs[] without any bounds check. rxq->bufs[] has only BTINTEL_PCIE_RX_DESCS_COUNT (64) entries, while frbd_tag can be any value 0-65535. A malicious or malfunctioning device can write an out-of-range frbd_tag, causing the driver to dereference an out-of-bounds data_buf pointer.

Additionally, cr_hia is read from a DMA-shared index array also writable by the device; if the device sets cr_hia >= rxq->count, the while-loop never terminates because cr_tia is wrapped via modulo rxq->count and can never equal an out-of-range cr_hia.

Add bounds validation for cr_hia and frbd_tag in the RX path, and cr_hia in the TX path. Log invalid values with bt_dev_err before returning.

Affected

• Linux >= c2b636b3f788d10486a6691ad6dd3ec4c93bd78e < f42cd95e679d5b78611cd2208cd1c41ad0045ffa
• Linux >= c2b636b3f788d10486a6691ad6dd3ec4c93bd78e < 8ec5838a35b03ac0cf3602452a369898051ffaf9
• Linux >= c2b636b3f788d10486a6691ad6dd3ec4c93bd78e < b29b70bfa12133423924fcd0327c19a802f7e368
• Linux >= c2b636b3f788d10486a6691ad6dd3ec4c93bd78e < 37a11129345337efd6eef8e62b03b6348cd0dd8b
• Linux 6.10

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.