Le 21/07/2021 à 18:19, Tomasz Torcz a écrit : > On Wed, Jul 21, 2021 at 06:00:15PM +0200, Didier Kryn wrote: >> Le 21/07/2021 à 16:51, Bernard Rosset via Dng a écrit : >>>> https://www.zdnet.com/article/nasty-linux-systemd-security-bug-revealed/ >>> I'll be projecting myself here, but I reckon sharing the original >>> source rather than journalistic articles whenever possible is best >>> towards a tech-savvy audience. >>> >>> The source (included in above article) is here: >>> https://blog.qualys.com/vulnerabilities-threat-research/2021/07/20/cve-2021-33910-denial-of-service-stack-exhaustion-in-systemd-pid-1 >> The code shows the use of strdupa(). There is a family of functions >> which are extensions of POSIX functions, with the suffix 'a' which >> allocate space for the returned string from the stack. They are very >> convenient for lazy programmer, but (slightly ?) dangerous and do not >> belong to POSIX. >> >> I've found a discussion between a developper and Lennart Poeterring >> in which LP recommends the addition of this kind of functions in Musl >> libc (which will certainly never happen). > That's amusing thought. strdupa() is in Musl: > http://git.musl-libc.org/cgit/musl/tree/include/string.h#n89 > alloca() is there, too: > http://git.musl-libc.org/cgit/musl/tree/include/alloca.h > At least strdupa() is just a macro conditionned by #ifedf _GNU_SOURCE.
Similarly alloca() is #defined as the compiler's built in alloca(). This is a way to provide the minimal service to people wanting to link with Musl programs developped for Glibc. I guess the pressure was too high. -- Didier _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
