Subject: Re: bin/792: su(1) ignores primary group, it and id(1) disagree with kernel on group membership
To: Jason Downs <downsj@PEAK.ORG>
From: Daniel Carosone <email@example.com.OZ.AU>
Date: 02/11/1995 12:35:35
Jason Downs writes:
> In message <199502110005.QAA00367@sun-lamp.cs.berkeley.edu>,
> Daniel Carosone writes:
> >I discovered that, while id(1) told me I was in group 0, su(1) told me
> >I was not in the correct group to su.
> >The su(1) program uses the getgrgid() function, which reads the
> >/etc/group file for secondary groups. It does not look at the primary
> >group. id and su should agree, this is clearly a bug, and a simple one
> >to fix.
> I'd say this is a bug. su(1) and id(1) should agree.
Yup. I just submitted a patch to fix this.
> >I went to the source of id(1) to see how it extracted the secondary
> >group membership from the kernel, so as to use the same mechanism in
> >su(1). I discovered that id also uses a variant of the /etc/group
> >database file access routines, and so there is the possibility for
> >disagreement between id(1) and the kernel.
All of this ranting is bogus, I was not paying attention to what I was
reading. id does behave as described above, but only when given a
> >I find it very confusing when id tells me I am in the right group to
> >su, and I can't, or when it tells me I am in the right group to access
> >a file, and I can't.
> This is how UN*X has been for a very long time. Changing it would
> certainly `feel' wrong.
Nope, apart from the general sentiment that Unix is often
inconsistent. see above.