From owner-freebsd-bugs@FreeBSD.ORG Wed Oct 11 13:10:18 2006 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 [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A019C16A403 for ; Wed, 11 Oct 2006 13:10:18 +0000 (UTC) (envelope-from gnats@FreeBSD.org) Received: from freefall.freebsd.org (freefall.freebsd.org [216.136.204.21]) by mx1.FreeBSD.org (Postfix) with ESMTP id E237A43D5A for ; Wed, 11 Oct 2006 13:10:17 +0000 (GMT) (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 k9BDAHih060387 for ; Wed, 11 Oct 2006 13:10:17 GMT (envelope-from gnats@freefall.freebsd.org) Received: (from gnats@localhost) by freefall.freebsd.org (8.13.4/8.13.4/Submit) id k9BDAHFI060386; Wed, 11 Oct 2006 13:10:17 GMT (envelope-from gnats) Resent-Date: Wed, 11 Oct 2006 13:10:17 GMT Resent-Message-Id: <200610111310.k9BDAHFI060386@freefall.freebsd.org> Resent-From: FreeBSD-gnats-submit@FreeBSD.org (GNATS Filer) Resent-To: freebsd-bugs@FreeBSD.org Resent-Reply-To: FreeBSD-gnats-submit@FreeBSD.org, trasz Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id EC77B16A403 for ; Wed, 11 Oct 2006 13:02:33 +0000 (UTC) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (www.freebsd.org [216.136.204.117]) by mx1.FreeBSD.org (Postfix) with ESMTP id 29DA743D62 for ; Wed, 11 Oct 2006 13:02:29 +0000 (GMT) (envelope-from nobody@FreeBSD.org) Received: from www.freebsd.org (localhost [127.0.0.1]) by www.freebsd.org (8.13.1/8.13.1) with ESMTP id k9BD2T3u024343 for ; Wed, 11 Oct 2006 13:02:29 GMT (envelope-from nobody@www.freebsd.org) Received: (from nobody@localhost) by www.freebsd.org (8.13.1/8.13.1/Submit) id k9BD2SbI024342; Wed, 11 Oct 2006 13:02:28 GMT (envelope-from nobody) Message-Id: <200610111302.k9BD2SbI024342@www.freebsd.org> Date: Wed, 11 Oct 2006 13:02:28 GMT From: trasz To: freebsd-gnats-submit@FreeBSD.org X-Send-Pr-Version: www-3.0 Cc: Subject: bin/104295: freopen(NULL, ...) does bad things to file offset. X-BeenThere: freebsd-bugs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Bug reports List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 11 Oct 2006 13:10:18 -0000 >Number: 104295 >Category: bin >Synopsis: freopen(NULL, ...) does bad things to file offset. >Confidential: no >Severity: non-critical >Priority: medium >Responsible: freebsd-bugs >State: open >Quarter: >Keywords: >Date-Required: >Class: sw-bug >Submitter-Id: current-users >Arrival-Date: Wed Oct 11 13:10:17 GMT 2006 >Closed-Date: >Last-Modified: >Originator: trasz >Release: 6.1 >Organization: >Environment: FreeBSD traszkan.ds7 6.2-PRERELEASE FreeBSD 6.2-PRERELEASE #1: Fri Sep 29 12:04:37 CEST 2006 trasz@traszkan.ds7:/usr/obj/usr/src/sys/TRASHCAN i386 >Description: Freopen(3) does bad things to the file offset when supplied with NULL as a file path (freopen(NULL, mode, fd);). The test program below returns: file offset before freopen is 100. file offset after freopen is 2399. >How-To-Repeat: #include int main(void) { int ret; FILE *f; f=fopen("/etc/passwd", "r"); if (f==NULL) { perror("fopen"); exit(-1); } ret=fseek(f, 100, SEEK_CUR); if (ret<0) { perror("fseek"); exit(-1); } ret=ftell(f); fprintf(stderr, "file offset before freopen is %d.\n", ret); f=freopen(NULL, "r", f); if (f==NULL) { perror("freopen"); exit(-1); } ret=ftell(f); fprintf(stderr, "file offset after freopen is %d.\n", ret); return 0; } >Fix: NOT TESTED: --- freopen.c.orig Wed Oct 11 14:59:25 2006 +++ freopen.c Wed Oct 11 15:00:47 2006 @@ -217,5 +217,9 @@ fp->_seek = __sseek; fp->_close = __sclose; FUNLOCKFILE(fp); + + if (file == NULL) + rewind(fp); + return (fp); } >Release-Note: >Audit-Trail: >Unformatted: