From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: AS31976 209.132.180.0/23 X-Spam-Status: No, score=-4.2 required=3.0 tests=AWL,BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by dcvr.yhbt.net (Postfix) with ESMTP id E425320248 for ; Thu, 28 Feb 2019 20:37:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732206AbfB1UhA (ORCPT ); Thu, 28 Feb 2019 15:37:00 -0500 Received: from mail-lj1-f196.google.com ([209.85.208.196]:44895 "EHLO mail-lj1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727874AbfB1Ug7 (ORCPT ); Thu, 28 Feb 2019 15:36:59 -0500 Received: by mail-lj1-f196.google.com with SMTP id q128so18348150ljb.11 for ; Thu, 28 Feb 2019 12:36:58 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=rtthsfx9gJCwTdIdG5WDl3DDNdPDpKMu18Ugg51Kq6o=; b=g8XfTtpvbliwvc+pM8oli/WTMr4N86D8u2D3hZ0jNiP/pHxYdWxgVY9iRAeGSY+Pto 8qdbKAPc1aBj4XVpXJntSgczhNziy0ZVcZhcK8xZ8QZ5NvVocZsyvdSe5TpoOnw17+ME F/iYYBcAIALKHIBJWvqcdzR/ewFAZt3vzg75dvhKPs5xlH9u9dHz9Jgt2y6rJBLwBzDB 2AfPUDXGbhVZwtr9a73GY2Se8VaUsEtfWX9Imhg1m3qATWWDz0GopGVnNd+AWT/lsv9p Q+yh1P1a6dxXJY5up4u0QNXFlx7JqaSfjB5harX8jI/kPeHTcXiM4DrX3nTPTE31K5Kb 6erg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=rtthsfx9gJCwTdIdG5WDl3DDNdPDpKMu18Ugg51Kq6o=; b=RmtoKZBtb6TYHU4pcNJwvp0M9nFBcjX+ZAlt+chPm8uq3+0V/+YNEyG40yz00Q1B84 ms77efSlk9kbSM1pFJmrtLnmL3SAv/jURHqm70END4WB9O5n/AHe5M3ufYF8H5mwdPvk vheddkyc9jtMorSLEzyhJo3fQF8Pk/JNDiHUspfyd2y4rxxEtpKpaIJhqTbKkZqVelJ5 nxPE6ttnFXVb1MzNQIPSwuBoSWuFTGaDEKWhSRJbfHq9GDMRjG3xZ4bqTBXwYj+aTl+7 bwn3X6AgMb9XJv5HJNfSGKaoo0evh7HtdZWo0tFVDyF9CGYFdvX3FV3M1hNDQPIACoOQ v95A== X-Gm-Message-State: APjAAAWFUsDfH7+wsgbHNn03xHIOgNk8B6S6igjtn+GXj0ayJWxBQmve zsNA+fsseDrDpLVReUjDiG2NIHAx X-Google-Smtp-Source: APXvYqzn1lYpdDibICRE60eqxzTcIm+aDD7MWnw3kSRKYawGNpVPQB1cmcweIQaff/BlOW6CSBxiKQ== X-Received: by 2002:a2e:80d6:: with SMTP id r22mr454310ljg.148.1551386216418; Thu, 28 Feb 2019 12:36:56 -0800 (PST) Received: from localhost.localdomain (31-211-229-121.customers.ownit.se. [31.211.229.121]) by smtp.gmail.com with ESMTPSA id l11sm4282415lja.38.2019.02.28.12.36.55 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 28 Feb 2019 12:36:55 -0800 (PST) From: =?UTF-8?q?Martin=20=C3=85gren?= To: git@vger.kernel.org Cc: Jeff King , "brian m . carlson" Subject: [PATCH v4 2/2] setup: fix memory leaks with `struct repository_format` Date: Thu, 28 Feb 2019 21:36:28 +0100 Message-Id: X-Mailer: git-send-email 2.21.0 In-Reply-To: References: <20190226174655.GE19606@sigill.intra.peff.net> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org After we set up a `struct repository_format`, it owns various pieces of allocated memory. We then either use those members, because we decide we want to use the "candidate" repository format, or we discard the candidate / scratch space. In the first case, we transfer ownership of the memory to a few global variables. In the latter case, we just silently drop the struct and end up leaking memory. Introduce an initialization macro `REPOSITORY_FORMAT_INIT` and a function `clear_repository_format()`, to be used on each side of `read_repository_format()`. To have a clear and simple memory ownership, let all users of `struct repository_format` duplicate the strings that they take from it, rather than stealing the pointers. Call `clear_...()` at the start of `read_...()` instead of just zeroing the struct, since we sometimes enter the function multiple times. Thus, it is important to initialize the struct before calling `read_...()`, so document that. It's also important because we might not even call `read_...()` before we call `clear_...()`, see, e.g., builtin/init-db.c. Teach `read_...()` to clear the struct on error, so that it is reset to a safe state, and document this. (In `setup_git_directory_gently()`, we look at `repo_fmt.hash_algo` even if `repo_fmt.version` is -1, which we weren't actually supposed to do per the API. After this commit, that's ok.) We inherit the existing code's combining "error" and "no version found". Both are signalled through `version == -1` and now both cause us to clear any partial configuration we have picked up. For "extensions.*", that's fine, since they require a positive version number. For "core.bare" and "core.worktree", we're already verifying that we have a non-negative version number before using them. Signed-off-by: Martin Ågren --- cache.h | 31 ++++++++++++++++++++++++++++--- builtin/init-db.c | 3 ++- repository.c | 3 ++- setup.c | 39 +++++++++++++++++++++++++++------------ worktree.c | 4 +++- 5 files changed, 62 insertions(+), 18 deletions(-) diff --git a/cache.h b/cache.h index ca36b44ee0..8c32c904c3 100644 --- a/cache.h +++ b/cache.h @@ -961,6 +961,10 @@ extern char *repository_format_partial_clone; extern const char *core_partial_clone_filter_default; extern int repository_format_worktree_config; +/* + * You _have_ to initialize a `struct repository_format` using + * `= REPOSITORY_FORMAT_INIT` before calling `read_repository_format()`. + */ struct repository_format { int version; int precious_objects; @@ -972,14 +976,35 @@ struct repository_format { struct string_list unknown_extensions; }; +/* + * Always use this to initialize a `struct repository_format` + * to a well-defined, default state before calling + * `read_repository()`. + */ +#define REPOSITORY_FORMAT_INIT \ +{ \ + .version = -1, \ + .is_bare = -1, \ + .hash_algo = GIT_HASH_SHA1, \ + .unknown_extensions = STRING_LIST_INIT_DUP, \ +} + /* * Read the repository format characteristics from the config file "path" into - * "format" struct. Returns the numeric version. On error, -1 is returned, - * format->version is set to -1, and all other fields in the struct are - * undefined. + * "format" struct. Returns the numeric version. On error, or if no version is + * found in the configuration, -1 is returned, format->version is set to -1, + * and all other fields in the struct are set to the default configuration + * (REPOSITORY_FORMAT_INIT). Always initialize the struct using + * REPOSITORY_FORMAT_INIT before calling this function. */ int read_repository_format(struct repository_format *format, const char *path); +/* + * Free the memory held onto by `format`, but not the struct itself. + * (No need to use this after `read_repository_format()` fails.) + */ +void clear_repository_format(struct repository_format *format); + /* * Verify that the repository described by repository_format is something we * can read. If it is, return 0. Otherwise, return -1, and "err" will describe diff --git a/builtin/init-db.c b/builtin/init-db.c index 41faffd28d..04c60eaad5 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -96,7 +96,7 @@ static void copy_templates(const char *template_dir) struct strbuf path = STRBUF_INIT; struct strbuf template_path = STRBUF_INIT; size_t template_len; - struct repository_format template_format; + struct repository_format template_format = REPOSITORY_FORMAT_INIT; struct strbuf err = STRBUF_INIT; DIR *dir; char *to_free = NULL; @@ -148,6 +148,7 @@ static void copy_templates(const char *template_dir) free(to_free); strbuf_release(&path); strbuf_release(&template_path); + clear_repository_format(&template_format); } static int git_init_db_config(const char *k, const char *v, void *cb) diff --git a/repository.c b/repository.c index 7b02e1dffa..df88705574 100644 --- a/repository.c +++ b/repository.c @@ -148,7 +148,7 @@ int repo_init(struct repository *repo, const char *gitdir, const char *worktree) { - struct repository_format format; + struct repository_format format = REPOSITORY_FORMAT_INIT; memset(repo, 0, sizeof(*repo)); repo->objects = raw_object_store_new(); @@ -165,6 +165,7 @@ int repo_init(struct repository *repo, if (worktree) repo_set_worktree(repo, worktree); + clear_repository_format(&format); return 0; error: diff --git a/setup.c b/setup.c index bb633942bb..ab6e8fd4c3 100644 --- a/setup.c +++ b/setup.c @@ -477,7 +477,7 @@ static int check_repository_format_gently(const char *gitdir, struct repository_ } repository_format_precious_objects = candidate->precious_objects; - repository_format_partial_clone = candidate->partial_clone; + repository_format_partial_clone = xstrdup_or_null(candidate->partial_clone); repository_format_worktree_config = candidate->worktree_config; string_list_clear(&candidate->unknown_extensions, 0); @@ -500,27 +500,38 @@ static int check_repository_format_gently(const char *gitdir, struct repository_ } if (candidate->work_tree) { free(git_work_tree_cfg); - git_work_tree_cfg = candidate->work_tree; + git_work_tree_cfg = xstrdup(candidate->work_tree); inside_work_tree = -1; } - } else { - free(candidate->work_tree); } return 0; } +static void init_repository_format(struct repository_format *format) +{ + const struct repository_format fresh = REPOSITORY_FORMAT_INIT; + + memcpy(format, &fresh, sizeof(fresh)); +} + int read_repository_format(struct repository_format *format, const char *path) { - memset(format, 0, sizeof(*format)); - format->version = -1; - format->is_bare = -1; - format->hash_algo = GIT_HASH_SHA1; - string_list_init(&format->unknown_extensions, 1); + clear_repository_format(format); git_config_from_file(check_repo_format, path, format); + if (format->version == -1) + clear_repository_format(format); return format->version; } +void clear_repository_format(struct repository_format *format) +{ + string_list_clear(&format->unknown_extensions, 0); + free(format->work_tree); + free(format->partial_clone); + init_repository_format(format); +} + int verify_repository_format(const struct repository_format *format, struct strbuf *err) { @@ -1008,7 +1019,7 @@ int discover_git_directory(struct strbuf *commondir, struct strbuf dir = STRBUF_INIT, err = STRBUF_INIT; size_t gitdir_offset = gitdir->len, cwd_len; size_t commondir_offset = commondir->len; - struct repository_format candidate; + struct repository_format candidate = REPOSITORY_FORMAT_INIT; if (strbuf_getcwd(&dir)) return -1; @@ -1045,9 +1056,11 @@ int discover_git_directory(struct strbuf *commondir, strbuf_release(&err); strbuf_setlen(commondir, commondir_offset); strbuf_setlen(gitdir, gitdir_offset); + clear_repository_format(&candidate); return -1; } + clear_repository_format(&candidate); return 0; } @@ -1056,7 +1069,7 @@ const char *setup_git_directory_gently(int *nongit_ok) static struct strbuf cwd = STRBUF_INIT; struct strbuf dir = STRBUF_INIT, gitdir = STRBUF_INIT; const char *prefix; - struct repository_format repo_fmt; + struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT; /* * We may have read an incomplete configuration before @@ -1146,6 +1159,7 @@ const char *setup_git_directory_gently(int *nongit_ok) strbuf_release(&dir); strbuf_release(&gitdir); + clear_repository_format(&repo_fmt); return prefix; } @@ -1203,9 +1217,10 @@ int git_config_perm(const char *var, const char *value) void check_repository_format(void) { - struct repository_format repo_fmt; + struct repository_format repo_fmt = REPOSITORY_FORMAT_INIT; check_repository_format_gently(get_git_dir(), &repo_fmt, NULL); startup_info->have_repository = 1; + clear_repository_format(&repo_fmt); } /* diff --git a/worktree.c b/worktree.c index d6a0ee7f73..b45bfeb9d3 100644 --- a/worktree.c +++ b/worktree.c @@ -444,7 +444,7 @@ int submodule_uses_worktrees(const char *path) DIR *dir; struct dirent *d; int ret = 0; - struct repository_format format; + struct repository_format format = REPOSITORY_FORMAT_INIT; submodule_gitdir = git_pathdup_submodule(path, "%s", ""); if (!submodule_gitdir) @@ -462,8 +462,10 @@ int submodule_uses_worktrees(const char *path) read_repository_format(&format, sb.buf); if (format.version != 0) { strbuf_release(&sb); + clear_repository_format(&format); return 1; } + clear_repository_format(&format); /* Replace config by worktrees. */ strbuf_setlen(&sb, sb.len - strlen("config")); -- 2.21.0