Messages in this thread | | | Subject | Re: VFS: Dynamic umask for the access rights of linked objects | Date | Wed, 01 Mar 2006 13:33:58 -0300 | From | Horst von Brand <> |
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Hauke Laging <mailinglisten@hauke-laging.de> wrote: > Am Mittwoch 01 März 2006 03:45 schrieb Sam Vilain: > > Of course this doesn't work if, like /tmp and /var/tmp are shipped as on > > every distribution, the directory has permissions 1777.
> I had this idea after the announcement of such a security problem in an > antivirus software. The rpm package was buggy and set wrong rights for the > installation directory /usr/whatever. So this is a real-world problem.
Right, some programs are broken.
[...]
> > What problem you are trying to solve?
> I want to prevent the case that superuser processes accidentally read or > write (system) files because they have been redirected there by a symlink > which has been created by a user who cannot access (or at least write) > these files hinself.
Don't do that then. Programs running as superuser should always be extra careful. Nothing (or nearly) should ever be run as "normal user" root.
Yes, root can shoot its feet at will. Always has been able to. Doing it by blindly following a symlink planted in her home or in /tmp by the local cracker-wannabe is just one (very minor) more way of doing so. -- Dr. Horst H. von Brand User #22616 counter.li.org Departamento de Informatica Fono: +56 32 654431 Universidad Tecnica Federico Santa Maria +56 32 654239 Casilla 110-V, Valparaiso, Chile Fax: +56 32 797513 - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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