From owner-svn-src-all@freebsd.org Mon May 15 17:34:18 2017 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 90313D6D677; Mon, 15 May 2017 17:34:18 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 6D3FB22B; Mon, 15 May 2017 17:34:18 +0000 (UTC) (envelope-from kib@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id v4FHYHtp035246; Mon, 15 May 2017 17:34:17 GMT (envelope-from kib@FreeBSD.org) Received: (from kib@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id v4FHYHPv035245; Mon, 15 May 2017 17:34:17 GMT (envelope-from kib@FreeBSD.org) Message-Id: <201705151734.v4FHYHPv035245@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: kib set sender to kib@FreeBSD.org using -f From: Konstantin Belousov Date: Mon, 15 May 2017 17:34:17 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r318299 - head/lib/libc/stdlib X-SVN-Group: head MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 15 May 2017 17:34:18 -0000 Author: kib Date: Mon May 15 17:34:17 2017 New Revision: 318299 URL: https://svnweb.freebsd.org/changeset/base/318299 Log: Simplify cleanup on failure in realpath(3). If realpath() allocated memory for result and failed, the memory is freed in each place where return is performed. More, the function needs to track the allocation status, to not free user-supplied buffer. Consolidate the memory handling in the wrapper, freeing the buffer if the actual worker failed. Reviewed by: emaste (previous version) Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D10670 Modified: head/lib/libc/stdlib/realpath.c Modified: head/lib/libc/stdlib/realpath.c ============================================================================== --- head/lib/libc/stdlib/realpath.c Mon May 15 17:14:53 2017 (r318298) +++ head/lib/libc/stdlib/realpath.c Mon May 15 17:34:17 2017 (r318299) @@ -47,32 +47,16 @@ __FBSDID("$FreeBSD$"); * components. Returns (resolved) on success, or (NULL) on failure, * in which case the path which caused trouble is left in (resolved). */ -char * -realpath(const char * __restrict path, char * __restrict resolved) +static char * +realpath1(const char *path, char *resolved) { struct stat sb; char *p, *q; size_t left_len, resolved_len, next_token_len; unsigned symlinks; - int m; ssize_t slen; char left[PATH_MAX], next_token[PATH_MAX], symlink[PATH_MAX]; - if (path == NULL) { - errno = EINVAL; - return (NULL); - } - if (path[0] == '\0') { - errno = ENOENT; - return (NULL); - } - if (resolved == NULL) { - resolved = malloc(PATH_MAX); - if (resolved == NULL) - return (NULL); - m = 1; - } else - m = 0; symlinks = 0; if (path[0] == '/') { resolved[0] = '/'; @@ -83,20 +67,14 @@ realpath(const char * __restrict path, c left_len = strlcpy(left, path + 1, sizeof(left)); } else { if (getcwd(resolved, PATH_MAX) == NULL) { - if (m) - free(resolved); - else { - resolved[0] = '.'; - resolved[1] = '\0'; - } + resolved[0] = '.'; + resolved[1] = '\0'; return (NULL); } resolved_len = strlen(resolved); left_len = strlcpy(left, path, sizeof(left)); } if (left_len >= sizeof(left) || resolved_len >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -125,8 +103,6 @@ realpath(const char * __restrict path, c if (resolved[resolved_len - 1] != '/') { if (resolved_len + 1 >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -158,27 +134,18 @@ realpath(const char * __restrict path, c */ resolved_len = strlcat(resolved, next_token, PATH_MAX); if (resolved_len >= PATH_MAX) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } - if (lstat(resolved, &sb) != 0) { - if (m) - free(resolved); + if (lstat(resolved, &sb) != 0) return (NULL); - } if (S_ISLNK(sb.st_mode)) { if (symlinks++ > MAXSYMLINKS) { - if (m) - free(resolved); errno = ELOOP; return (NULL); } slen = readlink(resolved, symlink, sizeof(symlink)); if (slen <= 0 || slen >= sizeof(symlink)) { - if (m) - free(resolved); if (slen < 0) { /* keep errno from readlink(2) call */ } else if (slen == 0) { @@ -207,8 +174,6 @@ realpath(const char * __restrict path, c if (p != NULL) { if (symlink[slen - 1] != '/') { if (slen + 1 >= sizeof(symlink)) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } @@ -218,16 +183,12 @@ realpath(const char * __restrict path, c left_len = strlcat(symlink, left, sizeof(symlink)); if (left_len >= sizeof(symlink)) { - if (m) - free(resolved); errno = ENAMETOOLONG; return (NULL); } } left_len = strlcpy(left, symlink, sizeof(left)); } else if (!S_ISDIR(sb.st_mode) && p != NULL) { - if (m) - free(resolved); errno = ENOTDIR; return (NULL); } @@ -241,3 +202,29 @@ realpath(const char * __restrict path, c resolved[resolved_len - 1] = '\0'; return (resolved); } + +char * +realpath(const char * __restrict path, char * __restrict resolved) +{ + char *m, *res; + + if (path == NULL) { + errno = EINVAL; + return (NULL); + } + if (path[0] == '\0') { + errno = ENOENT; + return (NULL); + } + if (resolved != NULL) { + m = NULL; + } else { + m = resolved = malloc(PATH_MAX); + if (resolved == NULL) + return (NULL); + } + res = realpath1(path, resolved); + if (res == NULL) + free(m); + return (res); +}