[TUHS] Who's behind the UNIX filesystem permission

Dave Horsfall dave at horsfall.org
Fri Aug 2 07:23:25 AEST 2019


On Thu, 1 Aug 2019, Doug McIlroy wrote:

> A common failing of Unix administration was a proliferation of suid-root 
> programs, e.g. mail(1). I recall one system that had a hundred such 
> programs. Sudo provided a way station between suid and ACLs.

I've always maintained that if you think you need setuid root (which is a 
gaping chest wound), you can invariably get away with setgid instead.

ObTrivia: Back in the 80s, some third-party software needed to be 
installed under "root".  I was suspicious, but I had little choice but to 
allow it (manager's orders; that company went under shortly after I left 
them).  Eventually I discovered why, when I had to clean up the mess: it 
actually *unlinked* directories; yes, you read that right...

-- Dave


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