repo: validate gitdir and gitlink ownership To match git's behavior with CVE 2022-29187, validate not only the working directory, but also the gitdir and gitlink (if it exists). This a follow up to CVE-2022-24765 that was fixed earlier.
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diff --git a/src/libgit2/repository.c b/src/libgit2/repository.c
index 09e81cd..17aec00 100644
--- a/src/libgit2/repository.c
+++ b/src/libgit2/repository.c
@@ -488,7 +488,7 @@ static int read_gitfile(git_str *path_out, const char *file_path)
typedef struct {
const char *repo_path;
git_str tmp;
- bool is_safe;
+ bool *is_safe;
} validate_ownership_data;
static int validate_ownership_cb(const git_config_entry *entry, void *payload)
@@ -496,52 +496,101 @@ static int validate_ownership_cb(const git_config_entry *entry, void *payload)
validate_ownership_data *data = payload;
if (strcmp(entry->value, "") == 0)
- data->is_safe = false;
+ *data->is_safe = false;
if (git_fs_path_prettify_dir(&data->tmp, entry->value, NULL) == 0 &&
strcmp(data->tmp.ptr, data->repo_path) == 0)
- data->is_safe = true;
+ *data->is_safe = true;
return 0;
}
-static int validate_ownership(const char *repo_path)
+static int validate_ownership_config(bool *is_safe, const char *path)
+{
+ validate_ownership_data ownership_data = {
+ path, GIT_STR_INIT, is_safe
+ };
+ git_config *config;
+ int error;
+
+ if (load_global_config(&config) != 0)
+ return 0;
+
+ error = git_config_get_multivar_foreach(config,
+ "safe.directory", NULL,
+ validate_ownership_cb,
+ &ownership_data);
+
+ git_config_free(config);
+ git_str_dispose(&ownership_data.tmp);
+
+ return error;
+}
+
+static int validate_ownership_path(bool *is_safe, const char *path)
{
- git_config *config = NULL;
- validate_ownership_data data = { repo_path, GIT_STR_INIT, false };
git_fs_path_owner_t owner_level =
GIT_FS_PATH_OWNER_CURRENT_USER |
GIT_FS_PATH_USER_IS_ADMINISTRATOR;
- bool is_safe;
- int error;
-
- if ((error = git_fs_path_owner_is(&is_safe, repo_path, owner_level)) < 0) {
- if (error == GIT_ENOTFOUND)
- error = 0;
+ int error = 0;
- goto done;
- }
+ if (path)
+ error = git_fs_path_owner_is(is_safe, path, owner_level);
- if (is_safe) {
+ if (error == GIT_ENOTFOUND) {
+ *is_safe = true;
error = 0;
- goto done;
}
- if (load_global_config(&config) == 0) {
- error = git_config_get_multivar_foreach(config, "safe.directory", NULL, validate_ownership_cb, &data);
+ return error;
+}
+
+static int validate_ownership(git_repository *repo)
+{
+ const char *validation_paths[3] = { NULL }, *path;
+ size_t validation_len = 0, i;
+ bool is_safe = false;
+ int error = 0;
+
+ /*
+ * If there's a worktree, validate the permissions to it *and*
+ * the git directory, and use the worktree as the configuration
+ * key for allowlisting the directory. In a bare setup, only
+ * look at the gitdir and use that as the allowlist. So we
+ * examine all `validation_paths` but use only the first as
+ * the configuration lookup.
+ */
+
+ if (repo->workdir)
+ validation_paths[validation_len++] = repo->workdir;
- if (!error && data.is_safe)
+ if (repo->gitlink)
+ validation_paths[validation_len++] = repo->gitlink;
+
+ validation_paths[validation_len++] = repo->gitdir;
+
+ for (i = 0; i < validation_len; i++) {
+ path = validation_paths[i];
+
+ if ((error = validate_ownership_path(&is_safe, path)) < 0)
goto done;
+
+ if (!is_safe)
+ break;
}
- git_error_set(GIT_ERROR_CONFIG,
- "repository path '%s' is not owned by current user",
- repo_path);
- error = GIT_EOWNER;
+ if (is_safe ||
+ (error = validate_ownership_config(&is_safe, validation_paths[0])) < 0)
+ goto done;
+
+ if (!is_safe) {
+ git_error_set(GIT_ERROR_CONFIG,
+ "repository path '%s' is not owned by current user",
+ path);
+ error = GIT_EOWNER;
+ }
done:
- git_config_free(config);
- git_str_dispose(&data.tmp);
return error;
}
@@ -918,7 +967,6 @@ int git_repository_open_ext(
gitlink = GIT_STR_INIT, commondir = GIT_STR_INIT;
git_repository *repo = NULL;
git_config *config = NULL;
- const char *validation_path;
int version = 0;
if (flags & GIT_REPOSITORY_OPEN_FROM_ENV)
@@ -977,12 +1025,11 @@ int git_repository_open_ext(
}
/*
- * Ensure that the git directory is owned by the current user.
+ * Ensure that the git directory and worktree are
+ * owned by the current user.
*/
- validation_path = repo->is_bare ? repo->gitdir : repo->workdir;
-
if (git_repository__validate_ownership &&
- (error = validate_ownership(validation_path)) < 0)
+ (error = validate_ownership(repo)) < 0)
goto cleanup;
cleanup: