On Fri, Feb 19, 2016 at 12:59:05PM +0100, Michael Kerrisk (man-pages) wrote: > On 18 February 2016 at 21:34, Matt Zimmerman <mdz@xxxxxxxxxx> wrote: > > Thanks for following up. My recommendation is to say something like: > > > > This function DOES NOT securely erase the contents of the environment. > > Security-conscious applications which need to do this should use .... > > instead. > > So, I think this report is a little confused, but mainly because of > the poor description in the man page. > > The security-conscious applications in this context are those that > want to precisely control the environment passed to an exec()ed > program. clearenv() cannot, indeed must not, try to erase the buffers > containing the environment definitions. (See putenv(3) to understand > why.) I've adjusted the man page in away that I hope explains things > better: > > The clearenv() function may be useful in security-conscious > applications that want to precisely control the environment that > is passed to programs executed using exec(3). The application > would do this by first clearing the environment and then adding > select environment variables. > > Note that the main effect of clearenv() is to adjust the value of > the pointer environ(7); this function does not erase the contents > of the buffers containing the environment definitions. Yes, that's much clearer, thank you! -- - mdz -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
