In the Linux kernel, the following vulnerability has been resolved: staging: greybus: uart: fix tty use after free User space can hold a tty open indefinitely and tty drivers must not release the underlying structures until the last user is gone. Switch to using the tty-port reference counter to manage the life time of the greybus tty state to avoid use after free after a disconnect.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.