From: Jeff King <peff@peff.net>
Date: Tue, 28 Apr 2015 06:02:22 GMT
Subject: Re: [PATCH v5 2/5] setup: sanity check file size in read_gitfile_gently
Message-ID: <20150428060222.GK24580@peff.net>
In-Reply-To: <1430030985-14499-3-git-send-email-erik.elfstrom@gmail.com>

On Sun, Apr 26, 2015 at 08:49:42AM +0200, Erik Elfström wrote:

> read_gitfile_gently will allocate a buffer to fit the entire file that
> should be read. Add a sanity check of the file size before opening to
> avoid allocating a potentially huge amount of memory if we come across
> a large file that someone happened to name ".git". The limit is set to
> a sufficiently unreasonable size that should never be exceeded by a
> genuine .git file.
>
> [...]
> +	if (st.st_size > PATH_MAX * 4) {
> +		error_code = READ_GITFILE_ERR_TOO_LARGE;
> +		goto cleanup_return;
> +	}

My understanding is that PATH_MAX is set absurdly low on Windows
systems (and doesn't actually represent the real limit of a path!).
Since the value is picked arbitrarily anyway, could use something more
independent (like 100K or something, which is large enough to be beyond
absurd and small enough that a malloc isn't a big deal)?

-Peff