Re: Bug#762839: bash without importing shell functions from the environment
Hi,
Thorsten Glaser:
> On Fri, 26 Sep 2014, Matthias Urlichs wrote:
>
> > In any case, adding "-p" to any #!/bin/bash shebang line looks like a very
> > good idea. Shall we add a Lintian check for this?
>
> ***ABSOLUTELY NOT***
>
> The -p option is for the shell to *not* drop privileges when
> called setuid.
Yes, it does that. It _also_ does all the other sanity-preserving things a
shell started in an insecure environment should do.
IMHO, code which calls a shell script with euid != ruid is buggy anyway,
because it _cannot_ depend on the shell to pro-actively fix that omission.
Any other program which happens to not be a #!/bin/bash shell script,
started the same way, will not reset its euid either. I don't expect any
other shell to care; the dash(1) manpage implies that it does not, for
instance.
Therefore I do not think that adding this flag would create any new
security problems.
Feel free to find a real-world counterexample.
--
-- Matthias Urlichs
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