Re: NetBSD Security Advisory 1999-001: select(2)/accept(2) race

[casper () HOLLAND SUN COM (Casper Dik)]

> > 2) Modify the kernel to not remove sockets from the accept(2) queue
> >    when they are closed.  A change that implements this has been added
> >    to NetBSD-current, and is available at:
> >        ftp://ftp.NetBSD.ORG/pub/NetBSD/misc/security/patches/19990120-accept
>
> This method works well btw. Linux has always done this, (by happy chance). Im
> _amazed_ this bug exists. It was documented/abused/used/fixed in so many
> different places at different times even back in 1990/1991 or so


The same happy coincidence happens in Solaris; accept() done when the
connection is already closed causes an EPROTO error.  (I'd need to check
whether that error disappeared again when native socket calls were
implemented)

Casper