From jonny@jonny.eng.br Sun Jul 5 00:51:22 1998 Received: from roma.coe.ufrj.br (jonny@roma.coe.ufrj.br [146.164.53.65]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id AAA01900 for ; Sun, 5 Jul 1998 00:51:20 -0700 (PDT) (envelope-from jonny@jonny.eng.br) Received: (from jonny@localhost) by roma.coe.ufrj.br (8.8.8/8.8.8) id EAA03831; Sun, 5 Jul 1998 04:51:20 -0300 (EST) (envelope-from jonny) Message-Id: <199807050751.EAA03831@roma.coe.ufrj.br> Date: Sun, 5 Jul 1998 04:51:20 -0300 (EST) From: Joao Carlos Mendes Luis Reply-To: jonny@jonny.eng.br To: FreeBSD-gnats-submit@freebsd.org Subject: accton on a append-only file X-Send-Pr-Version: 3.2 >Number: 7169 >Category: kern >Synopsis: cannot use accton on a append-only file >Confidential: no >Severity: serious >Priority: medium >Responsible: johan >State: closed >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Sun Jul 5 00:50:00 PDT 1998 >Closed-Date: Wed Jul 24 11:34:39 PDT 2002 >Last-Modified: Wed Jul 24 11:34:39 PDT 2002 >Originator: Joao Carlos Mendes Luis >Release: FreeBSD 2.2.6-STABLE i386 >Organization: COPPE/UFRJ >Environment: FreeBSD-stable (but bug is probably present in -current also) >Description: I want to raise the security of my system, making heavy use of securelevel and file flags. All log files should be append-only, ie, flagged sappend. This worked for most files, but not for accounting files (accton). acct(2) is returning EPERM for an append-only file as argument. >How-To-Repeat: $ chflags sappend /var/account/acct $ accton /var/account/acct >Fix: I don't have enough knowledge to fix, but the bug seems to be in the kern_acct.c file. I've sent a message about this to -hackers list, and received this answer. ... Message-Id: <199807041545.RAA13938@semyam.dinoco.de> cc: Joao Carlos Mendes Luis , seggers@semyam.dinoco.de To: hackers@FreeBSD.ORG Subject: Re: accton on a append-only file ? Date: Sat, 04 Jul 1998 17:45:36 +0200 From: Stefan Eggers > I've created the /var/account/acct file with sappend,sunlink flags, > but accton return EPERM. If I run accton before setting those flags, > This seems to be a bug, but I still have much to learn from VFS To me, too. It is because kern_acct.c in 2.2-stable opens the file for writing, not for appending. There is the problem: /* * If accounting is to be started to a file, open that file for * writing and make sure it's a 'normal'. */ if (uap->path != NULL) { NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, uap->path, p); error = vn_open(&nd, FWRITE, 0); if (error) return (error); Unless there is already a PR for this (check the PR database on the FreeBSD web pages) I'd suggest sending in a new one. > before searching for the culprit myself. Does it deserve a send-pr, > even without patches ? I think it's as easy as adding FAPPEND to the mode. The only problem is making sure that it has no unexpected side effects. If you like quote this email in the PR to point at a possible way to fix it. Stefan. -- Stefan Eggers Lu4 yao2 zhi1 ma3 li4, Max-Slevogt-Str. 1 ri4 jiu3 jian4 ren2 xin1. 51109 Koeln Federal Republic of Germany ... Taking a quick look at ufs_vnops.c, it really seems that a FWRITE|O_APPEND in the vnopen() call will fix, but again I'm not aware of possible problems. I've tested it at home, and it worked, but it would be much better if it was revised by a real FS hacker. >Release-Note: >Audit-Trail: State-Changed-From-To: open->suspended State-Changed-By: phk State-Changed-When: Tue Jul 7 02:52:57 PDT 1998 State-Changed-Why: awaiting fix & committer Responsible-Changed-From-To: freebsd-bugs->johan Responsible-Changed-By: johan Responsible-Changed-When: Sun Jun 30 12:31:04 PDT 2002 Responsible-Changed-Why: I will have a look at this. http://www.freebsd.org/cgi/query-pr.cgi?pr=7169 State-Changed-From-To: suspended->analyzed State-Changed-By: johan State-Changed-When: Fri Jul 5 12:00:15 PDT 2002 State-Changed-Why: This is still a problem in stable and current. I'm currently working on fixing this. http://www.freebsd.org/cgi/query-pr.cgi?pr=7169 State-Changed-From-To: analyzed->patched State-Changed-By: johan State-Changed-When: Wed Jul 10 10:34:05 PDT 2002 State-Changed-Why: I have committed a fix to current and will MFC in two weeks, unless some problem shows up. http://www.freebsd.org/cgi/query-pr.cgi?pr=7169 From: Johan Karlsson To: jonny@jonny.eng.br Cc: freebsd-gnats-submit@FreeBSD.org Subject: Re: kern/7169: cannot use accton on a append-only file Date: Wed, 10 Jul 2002 20:00:35 +0200 --Clx92ZfkiYIKRjnr Content-Type: text/plain; charset=us-ascii Content-Disposition: inline FYI the equivalent patch for 4-Stable is attached here. It should work on any 4.x version. /Johan K -- Johan Karlsson mailto:johan@FreeBSD.org --Clx92ZfkiYIKRjnr Content-Type: text/plain; charset=us-ascii Content-Disposition: attachment; filename="acc.diff" Index: kern_acct.c =================================================================== RCS file: /home/ncvs/src/sys/kern/kern_acct.c,v retrieving revision 1.23 diff -u -r1.23 kern_acct.c --- kern_acct.c 15 Dec 1999 23:01:54 -0000 1.23 +++ kern_acct.c 10 Jul 2002 17:51:46 -0000 @@ -127,18 +127,18 @@ /* * If accounting is to be started to a file, open that file for - * writing and make sure it's a 'normal'. + * appending and make sure it's a 'normal'. */ if (SCARG(uap, path) != NULL) { NDINIT(&nd, LOOKUP, NOFOLLOW, UIO_USERSPACE, SCARG(uap, path), p); - error = vn_open(&nd, FWRITE, 0); + error = vn_open(&nd, FWRITE | O_APPEND, 0); if (error) return (error); NDFREE(&nd, NDF_ONLY_PNBUF); VOP_UNLOCK(nd.ni_vp, 0, p); if (nd.ni_vp->v_type != VREG) { - vn_close(nd.ni_vp, FWRITE, p->p_ucred, p); + vn_close(nd.ni_vp, FWRITE | O_APPEND, p->p_ucred, p); return (EACCES); } } @@ -149,8 +149,8 @@ */ if (acctp != NULLVP || savacctp != NULLVP) { untimeout(acctwatch, NULL, acctwatch_handle); - error = vn_close((acctp != NULLVP ? acctp : savacctp), FWRITE, - p->p_ucred, p); + error = vn_close((acctp != NULLVP ? acctp : savacctp), + FWRITE | O_APPEND, p->p_ucred, p); acctp = savacctp = NULLVP; } if (SCARG(uap, path) == NULL) @@ -304,7 +304,8 @@ if (savacctp != NULLVP) { if (savacctp->v_type == VBAD) { - (void) vn_close(savacctp, FWRITE, NOCRED, NULL); + (void) vn_close(savacctp, FWRITE | O_APPEND, NOCRED, + NULL); savacctp = NULLVP; return; } @@ -318,7 +319,7 @@ if (acctp == NULLVP) return; if (acctp->v_type == VBAD) { - (void) vn_close(acctp, FWRITE, NOCRED, NULL); + (void) vn_close(acctp, FWRITE | O_APPEND, NOCRED, NULL); acctp = NULLVP; return; } --Clx92ZfkiYIKRjnr-- State-Changed-From-To: patched->closed State-Changed-By: johan State-Changed-When: Wed Jul 24 11:34:09 PDT 2002 State-Changed-Why: Fix committed to -stable. http://www.freebsd.org/cgi/query-pr.cgi?pr=7169 >Unformatted: