From 37a11129345337efd6eef8e62b03b6348cd0dd8b Mon Sep 17 00:00:00 2001 From: Ravindra Date: Tue, 15 Sep 2026 10:42:15 +0530 Subject: [PATCH] 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. Fixes: c2b636b3f788 ("Bluetooth: btintel_pcie: Add support for PCIe transport") Signed-off-by: Ravindra Signed-off-by: Luiz Augusto von Dentz --- drivers/bluetooth/btintel_pcie.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/drivers/bluetooth/btintel_pcie.c b/drivers/bluetooth/btintel_pcie.c index 6e6e2b19815c..2819e001797b 100644 --- a/drivers/bluetooth/btintel_pcie.c +++ b/drivers/bluetooth/btintel_pcie.c @@ -1099,6 +1099,11 @@ static void btintel_pcie_msix_tx_handle(struct btintel_pcie_data *data) txq = &data->txq; + if (cr_hia >= txq->count) { + bt_dev_err(data->hdev, "TXQ: invalid cr_hia %u", cr_hia); + return; + } + while (cr_tia != cr_hia) { data->tx_wait_done = true; wake_up(&data->tx_wait_q); @@ -1650,6 +1655,11 @@ static void btintel_pcie_msix_rx_handle(struct btintel_pcie_data *data) rxq = &data->rxq; + if (cr_hia >= rxq->count) { + bt_dev_err(hdev, "RXQ: invalid cr_hia %u", cr_hia); + return; + } + /* The firmware sends multiple CD in a single MSI-X and it needs to * process all received CDs in this interrupt. */ @@ -1657,6 +1667,12 @@ static void btintel_pcie_msix_rx_handle(struct btintel_pcie_data *data) urbd1 = &rxq->urbd1s[cr_tia]; ipc_print_urbd1(data->hdev, urbd1, cr_tia); + if (urbd1->frbd_tag >= rxq->count) { + bt_dev_err(hdev, "RXQ: invalid frbd_tag %u", + urbd1->frbd_tag); + return; + } + buf = &rxq->bufs[urbd1->frbd_tag]; if (!buf) { bt_dev_err(hdev, "RXQ: failed to get the DMA buffer for %d",