Re: [PATCH] color: protect against out-of-bounds array access/assignment

> want_color_fd() is designed to work only with standard input, output,
> and error file descriptors, and stores information about each descriptor
> in an array. However, it doesn't verify that the passed-in descriptor
> lives within that set, which, with a buggy caller, could lead to
> access/assignment outside the array bounds.

> 
> Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
> ---
> 
> Just something I noticed while studying this code in relation to a patch
> review.
> 
>  color.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/color.c b/color.c
> index b1c24c69de..b0be9ce505 100644
> --- a/color.c
> +++ b/color.c
> @@ -343,6 +343,9 @@ int want_color_fd(int fd, int var)
>  
>  	static int want_auto[3] = { -1, -1, -1 };
>  
> +	if (fd < 0 || fd >= ARRAY_SIZE(want_auto))
> +	    BUG("file descriptor out of range: %d", fd);
> +
>  	if (var < 0)
>  		var = git_use_color_default;
>  
> -- 
> 2.18.0.599.g4ce2a8faa4.dirty
> 
>