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.
Fixes: c2b636b3f7 ("Bluetooth: btintel_pcie: Add support for PCIe transport")
Signed-off-by: Ravindra <ravindra@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
37a1112934