CVE-2026-80569

Descrição

In the Linux kernel, the following vulnerability has been resolved: Input: synaptics-rmi4 - bound the F54 report size to the allocated buffer rmi_f54_work() reads a diagnostics report from the device into f54->report_data, sizing the transfer with rmi_f54_get_report_size(): report_size = rmi_f54_get_report_size(f54); ... for (i = 0; i < report_size; i += F54_REPORT_DATA_SIZE) { int size = min(F54_REPORT_DATA_SIZE, report_size - i); ... rmi_read_block(.., f54->report_data + i, size); } report_data is allocated once at probe from F54-s own electrode counts (array3_size(f54->num_tx_electrodes, f54->num_rx_electrodes, sizeof(u16))), but rmi_f54_get_report_size() computes the size from drv_data->num_*_electrodes when those are set, i.e. from the F55 function-s electrode counts. Both counts come straight from device queries (F54 and F55 each report up to 255 electrodes) and nothing constrains the F55 counts to the F54 ones. A malicious or malfunctioning RMI4 device that reports larger F55 electrode counts than its F54 counts makes report_size exceed the allocation, so the read loop writes past report_data (and the V4L2 dequeue memcpy() then reads past it). On conforming hardware the F55 configured electrodes are a subset of the F54 physical electrodes, so report_size never exceeds the buffer and well-behaved devices are unaffected. Record the allocation size and reject a report that does not fit, mirroring the existing zero-size check.