https://gcc.gnu.org/bugzilla/show_bug.cgi?id=72783
--- Comment #1 from Florian Weimer <fw at gcc dot gnu.org> --- Martin and I discussed this for a bit. The %ms hack does not work due to embedded NULs, which are copied to the destination buffer by scanf, do not terminate the string, and are (in most cases) detectable by the application. The new M flag raises POSIX compatibility concerns. The easiest way seems to warn if the output length cannot be bounded (say, with sscanf and an input string of limited length) and there are no length specifiers, and not attempt any format string rewriting or process termination operation. If there is a separate warning flag which controls this, maybe we can compile Fedora with -Werror=scanf-length.
