Date: Thu, 22 Feb 2001 23:44:57 -0800 From: Alfred Perlstein <bright@wintelcom.net> To: Kris Kennaway <kris@obsecurity.org> Cc: Marcel Moolenaar <marcel@cup.hp.com>, arch@FreeBSD.ORG Subject: Re: sysctl kern.fallback_elf_brand Message-ID: <20010222234457.D8663@fw.wintelcom.net> In-Reply-To: <20010222233800.A1394@mollari.cthul.hu>; from kris@obsecurity.org on Thu, Feb 22, 2001 at 11:38:01PM -0800 References: <3A960EF8.75C3FC53@cup.hp.com> <20010222233800.A1394@mollari.cthul.hu>
next in thread | previous in thread | raw e-mail | index | archive | help
* Kris Kennaway <kris@obsecurity.org> [010222 23:38] wrote: > On Thu, Feb 22, 2001 at 11:19:20PM -0800, Marcel Moolenaar wrote: > > Hi, > > > > I'm worried about the default value of the kern.fallback_elf_brand syctl > > (= 9 -> FreeBSD). It basicly tells the kernel that binaries without any > > branding are FreeBSD binaries. Since our binaries are always branded > > (AFAICT), this seems to me as the wrong default. > > > > One problem with this is that unbranded static Linux binaries are > > executed as FreeBSD native binaries and there's a high chance of them > > rebooting the machine if run as root. > > > > I think we need to disable the fallback ELF branding when no ABI > > compatibility module is loaded. Otherwise we can set the fallback to the > > one ABI module, or when multiple are loaded, the first. In the latter > > case, the first may not be the preferred one, so we probably need to > > have a bit more tuning than simply selecting the first. > > > > Of course, we can also set the default to 3 (=Linux) under the > > assumption that the Linuxulator is the most frequently used ABI module. > > > > Thoughts? > > I've run into the unbranded Linux binary reboot before..very > annoying. I agree the default should be changed. Why does this happen? Does the exec code freak out if the default isn't present, or does some common syscall just happen to map to Linux's reboot syscall? -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-arch" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010222234457.D8663>