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

Vulnerability Description

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.

References

• https://git.kernel.org/stable/c/44b9620e82bbec2b9a6ac77f63913636d84f96dc
• https://git.kernel.org/stable/c/f704a80d9fa268e51a6cc5242714502c3c1fa605
• https://git.kernel.org/stable/c/0007ef098dab48f1ba58364c40b4809f1e21b130
• https://git.kernel.org/stable/c/6f18d174b73d0ceeaa341f46c0986436b3aefc9a