CVE-2025-38429

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

bus: mhi: ep: Update read pointer only after buffer is written

Inside mhi_ep_ring_add_element, the read pointer (rd_offset) is updated before the buffer is written, potentially causing race conditions where the host sees an updated read pointer before the buffer is actually written. Updating rd_offset prematurely can lead to the host accessing an uninitialized or incomplete element, resulting in data corruption.

Invoke the buffer write before updating rd_offset to ensure the element is fully written before signaling its availability.

This vulnerability poses minimal risk to Red Hat environments because the underlying Modem Host Interface endpoint subsystem is not enabled or supported across Red Hat Enterprise Linux releases. The flaw stems from an out-of-order memory signaling issue during endpoint ring buffer management, which could allow a host system to read uninitialized data. Because the affected driver components are absent from Red Hat enterprise kernels, default enterprise installations are unaffected.