FreeBSD: VID-5afcc9a4-7e04-11ee-8e38-002590c1f29c (CVE-2023-5941): FreeBSD -- libc stdio buffer overflow

Problem Description: For line-buffered streams the __sflush() function did not correctly update the FILE object's write space member when the write(2) system call returns an error. Impact: Depending on the nature of an application that calls libc's stdio functions and the presence of errors returned from the write(2) system call (or an overridden stdio write routine) a heap buffer overfly may occur. Such overflows may lead to data corruption or the execution of arbitrary code at the privilege level of the calling program.