In the Linux kernel, the following vulnerability has been resolved: ring-buffer: Do not warn in ringbuffermapgetreader() when reader catches up The function ringbuffermapgetreader() is a bit more strict than the other get reader functions, and except for certain situations the rbgetreaderpage() should not return NULL. If it does, it triggers a warning. This warning was triggering but after looking at why, it was because another acceptable situation was happening and it wasn't checked for. If the reader catches up to the writer and there's still data to be read on the reader page, then the rbgetreaderpage() will return NULL as there's no new page to get. In this situation, the reader page should not be updated and no warning should trigger.