Subject: Re: [PATCH v2 6/6] submodule--helper: introduce new update-module-mode helper

From: SZEDER Gábor <[email-masked]>
Date: Tue, 17 Jul 2018 09:59:59 +0200

> diff --git a/builtin/submodule--helper.c b/builtin/submodule--helper.c
> index 034ba1bb2e0..d4cb7c72e33 100644
> --- a/builtin/submodule--helper.c
> +++ b/builtin/submodule--helper.c

> +static int module_update_module_mode(int argc, const char **argv, const char *prefix)
> +{
> +	const char *path, *update = NULL;
> +	int just_cloned;
> +	struct submodule_update_strategy update_strategy = { .type = SM_UPDATE_CHECKOUT };
> +
> +	if (argc < 3 || argc > 4)
> +		die("submodule--helper update-module-clone expects <just-cloned> <path> [<update>]");
> +
> +	just_cloned = git_config_int("just_cloned", argv[1]);
> +	path = argv[2];
> +
> +	if (argc == 4)
> +		update = argv[3];
> +
> +	determine_submodule_update_strategy(the_repository,
> +					    just_cloned, path, update,
> +					    &update_strategy);
> +	fprintf(stdout, submodule_strategy_to_string(&update_strategy));

Various compilers warn about the potential insecurity of the above
call:

      CC builtin/submodule--helper.o
  builtin/submodule--helper.c: In function ‘module_update_module_mode’:
  builtin/submodule--helper.c:1502:2: error: format not a string literal and no format arguments [-Werror=format-security]
    fprintf(stdout, submodule_strategy_to_string(&update_strategy));
    ^
  cc1: all warnings being treated as errors
  Makefile:2261: recipe for target 'builtin/submodule--helper.o' failed
  make: *** [builtin/submodule--helper.o] Error 1

I think it should either use an explicit format string:

  fprintf(stdout, "%s", submodule_strategy_to_string(&update_strategy));

or, perhaps better yet, simply use fputs().

> +
> +	return 0;
> +}