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=-4.0 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, RCVD_IN_MSPIKE_H3,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE 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 1F4001F619 for ; Tue, 10 Mar 2020 13:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731567AbgCJNR5 (ORCPT ); Tue, 10 Mar 2020 09:17:57 -0400 Received: from mail-wm1-f66.google.com ([209.85.128.66]:37417 "EHLO mail-wm1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731421AbgCJNLa (ORCPT ); Tue, 10 Mar 2020 09:11:30 -0400 Received: by mail-wm1-f66.google.com with SMTP id a141so1290816wme.2 for ; Tue, 10 Mar 2020 06:11:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=message-id:in-reply-to:references:from:date:subject:fcc :content-transfer-encoding:mime-version:to:cc; bh=xPAvNSy/JO+ApfEIL+TKNP4JWnRTvx1KvqL9PEO8/7o=; b=VKX/g5Mo9Kz331HiCZLLeG4OuPbFLtu98fn+UaIEDd9TZMWicU67neRknrlXA3LP8u GlU0W9uMesnVXHRCuY3++AD5z/vIvObKF548f9Swk0ZLUowQn9835lJ+Fhs/64TqIBAu 0mEa7Nv9ZA4mnbrfJxbYDNWISkRECqUDeKu7UixRnB2CqluNhe4e1bGtgFrqTneSR8NL 4wn5gh1S7ByQOFHCnYmgAKTnimVKXzGc0hqkDSjyyNbh/LuYTC83qI6W12QlqExMdwX2 H9H8RAz/sJFK9gb5t3Xdc9nCUxTRkPUz/a3fhErsn4P7fQFwDQmav/BEV+mj8LY9b1M8 legw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:message-id:in-reply-to:references:from:date :subject:fcc:content-transfer-encoding:mime-version:to:cc; bh=xPAvNSy/JO+ApfEIL+TKNP4JWnRTvx1KvqL9PEO8/7o=; b=GIrqm6p6CuXeVYN0/RRh49FD+tRzw7KTz23uEBEnh6qAhMcH/bvMxDglspECV69Y8y 60VtciskLwwyI7H3hTkqxgjJg7zMDguy+qF/vHNbxpuPBufX5/Ey9ur5hKHOGBI3w5Z0 uYb/r5rj7f6m/s0eA9AW0Lg8IMzjYh3//uOENrC55IujaXj98Ijdk2eqg+rbz21rZy48 sbLkYrrYuMgLJ+xJNCaGZLanzrj2CJ1mKkAD7ZxzX1I+hNA6Qn96SiHeYUU8Y8m2mOs+ abVBc+Udk0eFXrOx1tCi1AG30M2qTOT5Rrf4rgC1ZJjXb8Wa8NYPUxrjXNPsZChJkDci 6JZQ== X-Gm-Message-State: ANhLgQ2H4nQkXVgolkzTUxEl8KyjXt/W0E+1xXS6V2AGZVVxbLOU0Spq brVjF9OGzAqobxZkfVq+jSh2f+z8 X-Google-Smtp-Source: ADFU+vuHiEQiVOKSwGG6I3YDVaSleCaHQwP6RfT2o9jzwhNb5+d+MffqjuxgAOHsLDSAVGI3PynMxA== X-Received: by 2002:a1c:a70f:: with SMTP id q15mr2235578wme.66.1583845888547; Tue, 10 Mar 2020 06:11:28 -0700 (PDT) Received: from [127.0.0.1] ([13.74.141.28]) by smtp.gmail.com with ESMTPSA id v8sm64062036wrw.2.2020.03.10.06.11.26 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 10 Mar 2020 06:11:26 -0700 (PDT) Message-Id: In-Reply-To: References: From: "Alexandr Miloslavskiy via GitGitGadget" Date: Tue, 10 Mar 2020 13:11:21 +0000 Subject: [PATCH v2 1/4] set_git_dir: fix crash when used with real_path() Fcc: Sent Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit MIME-Version: 1.0 To: git@vger.kernel.org Cc: Junio C Hamano , Alexandr Miloslavskiy , Alexandr Miloslavskiy Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org From: Alexandr Miloslavskiy `real_path()` returns result from a shared buffer, inviting subtle reentrance bugs. One of these bugs occur when invoked this way: set_git_dir(real_path(git_dir)) In this case, `real_path()` has reentrance: real_path read_gitfile_gently repo_set_gitdir setup_git_env set_git_dir_1 set_git_dir Later, `set_git_dir()` uses its now-dead parameter: !is_absolute_path(path) Fix this by using a dedicated `strbuf` to hold `strbuf_realpath()`. Signed-off-by: Alexandr Miloslavskiy --- builtin/init-db.c | 4 ++-- cache.h | 2 +- environment.c | 11 ++++++++++- path.c | 2 +- setup.c | 18 +++++++++--------- 5 files changed, 23 insertions(+), 14 deletions(-) diff --git a/builtin/init-db.c b/builtin/init-db.c index 944ec77fe10..5bf61a7e056 100644 --- a/builtin/init-db.c +++ b/builtin/init-db.c @@ -356,12 +356,12 @@ int init_db(const char *git_dir, const char *real_git_dir, if (!exist_ok && !stat(real_git_dir, &st)) die(_("%s already exists"), real_git_dir); - set_git_dir(real_path(real_git_dir)); + set_git_dir(real_git_dir, 1); git_dir = get_git_dir(); separate_git_dir(git_dir, original_git_dir); } else { - set_git_dir(real_path(git_dir)); + set_git_dir(git_dir, 1); git_dir = get_git_dir(); } startup_info->have_repository = 1; diff --git a/cache.h b/cache.h index 37c899b53f7..8cee257d3d7 100644 --- a/cache.h +++ b/cache.h @@ -543,7 +543,7 @@ const char *get_git_common_dir(void); char *get_object_directory(void); char *get_index_file(void); char *get_graft_file(struct repository *r); -void set_git_dir(const char *path); +void set_git_dir(const char *path, int make_realpath); int get_common_dir_noenv(struct strbuf *sb, const char *gitdir); int get_common_dir(struct strbuf *sb, const char *gitdir); const char *get_git_namespace(void); diff --git a/environment.c b/environment.c index e72a02d0d57..c436de31eef 100644 --- a/environment.c +++ b/environment.c @@ -345,11 +345,20 @@ static void update_relative_gitdir(const char *name, free(path); } -void set_git_dir(const char *path) +void set_git_dir(const char *path, int make_realpath) { + struct strbuf realpath = STRBUF_INIT; + + if (make_realpath) { + strbuf_realpath(&realpath, path, 1); + path = realpath.buf; + } + set_git_dir_1(path); if (!is_absolute_path(path)) chdir_notify_register(NULL, update_relative_gitdir, NULL); + + strbuf_release(&realpath); } const char *get_log_output_encoding(void) diff --git a/path.c b/path.c index 88cf5930073..c5a8fe4f0c3 100644 --- a/path.c +++ b/path.c @@ -850,7 +850,7 @@ const char *enter_repo(const char *path, int strict) } if (is_git_directory(".")) { - set_git_dir("."); + set_git_dir(".", 0); check_repository_format(); return path; } diff --git a/setup.c b/setup.c index 4ea7a0b081b..fa4317e707a 100644 --- a/setup.c +++ b/setup.c @@ -725,7 +725,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv, } /* #18, #26 */ - set_git_dir(gitdirenv); + set_git_dir(gitdirenv, 0); free(gitfile); return NULL; } @@ -747,7 +747,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv, } else if (!git_env_bool(GIT_IMPLICIT_WORK_TREE_ENVIRONMENT, 1)) { /* #16d */ - set_git_dir(gitdirenv); + set_git_dir(gitdirenv, 0); free(gitfile); return NULL; } @@ -759,14 +759,14 @@ static const char *setup_explicit_git_dir(const char *gitdirenv, /* both get_git_work_tree() and cwd are already normalized */ if (!strcmp(cwd->buf, worktree)) { /* cwd == worktree */ - set_git_dir(gitdirenv); + set_git_dir(gitdirenv, 0); free(gitfile); return NULL; } offset = dir_inside_of(cwd->buf, worktree); if (offset >= 0) { /* cwd inside worktree? */ - set_git_dir(real_path(gitdirenv)); + set_git_dir(gitdirenv, 1); if (chdir(worktree)) die_errno(_("cannot chdir to '%s'"), worktree); strbuf_addch(cwd, '/'); @@ -775,7 +775,7 @@ static const char *setup_explicit_git_dir(const char *gitdirenv, } /* cwd outside worktree */ - set_git_dir(gitdirenv); + set_git_dir(gitdirenv, 0); free(gitfile); return NULL; } @@ -804,7 +804,7 @@ static const char *setup_discovered_git_dir(const char *gitdir, /* #16.2, #17.2, #20.2, #21.2, #24, #25, #28, #29 (see t1510) */ if (is_bare_repository_cfg > 0) { - set_git_dir(offset == cwd->len ? gitdir : real_path(gitdir)); + set_git_dir(gitdir, (offset != cwd->len)); if (chdir(cwd->buf)) die_errno(_("cannot come back to cwd")); return NULL; @@ -813,7 +813,7 @@ static const char *setup_discovered_git_dir(const char *gitdir, /* #0, #1, #5, #8, #9, #12, #13 */ set_git_work_tree("."); if (strcmp(gitdir, DEFAULT_GIT_DIR_ENVIRONMENT)) - set_git_dir(gitdir); + set_git_dir(gitdir, 0); inside_git_dir = 0; inside_work_tree = 1; if (offset >= cwd->len) @@ -856,10 +856,10 @@ static const char *setup_bare_git_dir(struct strbuf *cwd, int offset, die_errno(_("cannot come back to cwd")); root_len = offset_1st_component(cwd->buf); strbuf_setlen(cwd, offset > root_len ? offset : root_len); - set_git_dir(cwd->buf); + set_git_dir(cwd->buf, 0); } else - set_git_dir("."); + set_git_dir(".", 0); return NULL; } -- gitgitgadget