Re: FD's 0..2 and suid/sgid procs (Was: Crash a redhat 5.1 linux

From: Alan Cox (alanat_private)
Date: Thu Jul 30 1998 - 10:41:28 PDT

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    > Alan Cox actually is the first person who highlighted this sort of
    > vulnerability to me.  Does anyone know if the OpenBSD approach is
    
    Im certainly not its discoverer however.
    
    > suid/sgid program bogus stdin/stdout/stderr)?  Also, is a similar patch
    > in the works for Linux?  (I ask, because I'm a Linux user myself.)
    
    Someone was working on one yes
    
    > And, is there any overwhelming reason why you wouldn't make the same
    > guarantee that fd's 0..2 are open for all processes, rather than just
    > suid/sgid processes?
    
    Actually for the general case you shouldnt do it. Passing a closed fd
    is valid Unix behaviour, so you cease to really be "unix" by doing it.
    
    Obviously there are sometimes advantages to not following unix tradition
    totally
    



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