In the Linux kernel, the following vulnerability has been resolved: Bluetooth: hci_qca: fix NULL pointer dereference in qca_setup() for non-serdev device hu->serdev is NULL for hci_uart attached via non-serdev paths, but qca_setup() unconditionally calls serdev_device_get_drvdata(hu->serdev) and dereferences the result, causing a NULL pointer dereference. Fix by guarding the dereference with a NULL check, consistent with the rest of qca_setup().