Date: Tue, 12 Mar 2002 15:24:27 +0100 From: "Koster, K.J." <K.J.Koster@kpn.com> To: 'Michael Lucas' <mwlucas@blackhelicopters.org> Cc: java@FreeBSD.ORG Subject: RE: plug-in error? Message-ID: <59063B5B4D98D311BC0D0001FA7E452205FDA46D@l04.research.kpn.com>
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Dear Michael, > > However, just for my information, what the heck is this "Hrajuxz" that > I'm supposed to symlink the nonexistent malloc.conf to? > man malloc. It's a gross hack^W^Welegant solution to run-time configure the behaviour of FreeBSD's malloc. I believe phk@ is responsible for this. Interesting side note: Poul-Henning sent the following message to FreeBSD's security officer, regarding a zlib security advisory. http://www.linuxsecurity.com/advisories/redhat_advisory-1963.html ------- Forwarded Message To: security-officer@freebsd.org Subject: the zlib double free bug From: Poul-Henning Kamp <phk@freebsd.org> Date: Mon, 11 Mar 2002 23:13:57 +0100 Message-ID: <58959.1015884837@critter.freebsd.dk> Sender: phk@critter.freebsd.dk As author of our malloc(3) it is my opinion that we are not vulnerable to this (kind of) bug. Most mallocs keep their housekeeping data right next to the allocated range. This gives rise to all sorts of unpleassant situations if programs stray outside the dotted line, free(3) things twice or free(3) modified pointers. phkmalloc(3) does not store housekeeping next to allocated data, and in particular it has code that detects and complains about exactly the kind of double free this advisory talks about: critter phk> cat a.c main() { char *p; p = malloc(256); p = malloc(256); free(p); free(p); } critter phk> make a cc -O -pipe a.c -o a a.c: In function `main': a.c:7: warning: assignment makes pointer from integer without a cast a.c:8: warning: assignment makes pointer from integer without a cast critter phk> ./a a in free(): error: chunk is already free Abort (core dumped) critter phk> The malloc flag 'A' determines if the situation is just warned about or if the program should call abort(3). - -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 phk@FreeBSD.ORG | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence. ------- End of Forwarded Message Kees Jan ===================================================== You can't have everything. Where would you put it? [Steven Wright] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-java" in the body of the message
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