Re: /etc/utmp

Pat Myrto (ole!rwing!pat@nwnexus.wa.com)
Tue, 29 Mar 94 9:22:52 PST

"In the previous message, Jeff Allen said..."
> 
> Pat Myrto wrote:
> > Seems anything creating a file while running with root privs is
> > full of gotchas, especially with symlinks around.  There is supposed
> > to be a 'safefile' function in the mail command that if used properly
> > makes sure the file isn't a symlink or being switched under it, I
> > would like to see an example of how that is done and not being subject
> > to race conditions.
> 
> There is some code in taintperl to make sure that a symlink swap
> hasn't taken place beneath the SUID scipt in question. Grep the perl
> sources for "Mail". Larry has left a little surprise for would-be
> hackers. :)

Thanks for pointing that out - I will check that out.  Sounds like an idea
I can unashamedly borrow...  :-)

> 
> You may be able to work with it and get the kind of routine you are
> talking about.

Great!!

-- 
pat@rwing  [If all fails, try:  rwing!pat@ole.cdac.com]  Pat Myrto - Seattle WA
"No one has the right to destroy another person's belief by demanding
empirical evidence."  --   Ann Landers, nationally syndicated advice columnist
and Director at Handgun Control Inc.