Date: Sat, 25 Nov 2000 02:12:11 -0800 From: Alfred Perlstein <bright@wintelcom.net> To: Brian Feldman <green@FreeBSD.org> Cc: cvs-committers@FreeBSD.org, cvs-all@FreeBSD.org Subject: Re: cvs commit: src/usr.sbin/inetd builtins.c Message-ID: <20001125021211.H8051@fw.wintelcom.net> In-Reply-To: <200011250413.UAA16251@freefall.freebsd.org>; from green@FreeBSD.org on Fri, Nov 24, 2000 at 08:13:05PM -0800 References: <200011250413.UAA16251@freefall.freebsd.org>
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* Brian Feldman <green@FreeBSD.org> [001124 20:13] wrote: > green 2000/11/24 20:13:05 PST > > Modified files: > usr.sbin/inetd builtins.c > Log: > Security fix: correctly set groups according to the user. Previously, > root's groups' permissions were being used, so a user could read up to > 16 (excluding initial whitespace) bytes of e.g. a wheel-accessible file. Was this reviewed by anyone? Security fixes need review. > Also, don't allow blocking on the opening of ~/.fakeid, so replace a fopen() > with open() and fdopen(). I knew I'd be going to hell for using C file > streams instead of POSIX syscalls... What happens if ~/.fakeid is a FIFO without a writer/reader? Is this the blocking you're trying to avoid? I think you may have a problem here because you don't use fclose later, you may be leaking stdio streams with no backing fd. Don't you need to change: + if (fakeid_fd != -1) + close(fakeid_fd); to something like: if (fakeid != NULL) fclose(fakeid); else if fakeid_fd != -1) close(fakeid_fd); There's also a problem because this close isn't part of the 'else' clause above, what happens is that you may call close on fakeid_fd (after the 'else' clause) after calling fclose on it already in the 'if' clause. Doesn't the fstat need to happen before the fdopen? (to avoid blocking on FIFOs or other wierdness). What's going on here? And why was it MFC'd already? Maybe I'm wrong but these are some _possible_ bugs that I discovered after a cursory examination of the change, had it been dicussed I'd have either realized I was wrong or we could have had a proper fix the first time. -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] "I have the heart of a child; I keep it in a jar on my desk." To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe cvs-all" in the body of the message
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