From owner-freebsd-bugs@FreeBSD.ORG Mon May 7 21:20:14 2007 Return-Path: X-Original-To: freebsd-bugs@hub.freebsd.org Delivered-To: freebsd-bugs@hub.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 9837916A402 for ; Mon, 7 May 2007 21:20:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [69.147.83.40]) by mx1.freebsd.org (Postfix) with ESMTP id 415ED13C43E for ; Mon, 7 May 2007 21:20:14 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (gnats@localhost [127.0.0.1]) by freefall.freebsd.org (8.13.4/8.13.4) with ESMTP id l47LKEhD016701 for ; Mon, 7 May 2007 21:20:14 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.4/8.13.4/Submit) id l47LKEYs016700; Mon, 7 May 2007 21:20:14 GMT (envelope-from gnats) Date: Mon, 7 May 2007 21:20:14 GMT Message-Id: <200705072120.l47LKEYs016700@freefall.freebsd.org> To: freebsd-bugs@FreeBSD.org From: John E Hein Cc: Subject: Re: bin/112336: install -S (safe copy) with -C or -p is not so safe X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: John E Hein List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 May 2007 21:20:14 -0000 The following reply was made to PR bin/112336; it has been noted by GNATS. From: John E Hein To: FreeBSD-gnats-submit@FreeBSD.org, freebsd-bugs@FreeBSD.org Cc: Subject: Re: bin/112336: install -S (safe copy) with -C or -p is not so safe Date: Mon, 7 May 2007 15:13:24 -0600 Here is a patch that implements 2 and was simpler than I thought it would be. It creates the temp file and does a rename, not only if the contents of the "from" & "to" files don't match, but also if perms/ownership don't match. One optimization could be to try to do the chown/chmod first and if that succceeds and the files match contents, don't bother with the temp file. But that seems to be needlessly complex for the relatively miniscule number of cases where we could gain from the added pedantry. And there may be edge case failures associated with an early chmod/chown. Any committers willing to take this one? Index: src/usr.bin/xinstall/xinstall.c =================================================================== RCS file: /base/FreeBSD-CVS/src/usr.bin/xinstall/xinstall.c,v retrieving revision 1.67 diff -u -p -r1.67 xinstall.c --- src/usr.bin/xinstall/xinstall.c 6 Mar 2006 21:52:59 -0000 1.67 +++ src/usr.bin/xinstall/xinstall.c 7 May 2007 20:52:18 -0000 @@ -317,7 +317,19 @@ install(const char *from_name, const cha if (docompare && !dostrip && target) { if ((to_fd = open(to_name, O_RDONLY, 0)) < 0) err(EX_OSERR, "%s", to_name); - if (devnull) + /* + * Even if the contents are the same, we want to rename + * temp files when doing a "safe" copy if the + * permissions and ownership need to change. We may + * not have permission to chown/chmod the "to" file + * directly. + */ + if (tempcopy && + ((gid != (gid_t)-1 && gid != to_sb.st_gid) || + (uid != (uid_t)-1 && uid != to_sb.st_uid) || + (mode != (to_sb.st_mode & ALLPERMS)))) + files_match = 0; + else if (devnull) files_match = to_sb.st_size == 0; else files_match = !(compare(from_fd, from_name,