Re: [PATCH v8 1/4] sha1_file.c: support reading from a loose object of unknown type

[Jeff King <peff@peff.net>]

On Tue, Apr 21, 2015 at 04:56:08PM +0530, karthik nayak wrote:

> >>+       status = unpack_sha1_header(stream, map, mapsize, buffer, bufsiz);
> >
> >I wonder if we would feel comfortable just running this NUL-check as
> >part of unpack_sha1_header (i.e., in all code paths). It _shouldn't_
> >trigger in normal use, but I wonder if there would be any downsides
> >(e.g., maliciously crafted objects getting us to allocate memory or
> >something; I think it is fairly easy to convince git to allocate memory,
> >though).
> >
> But why would we want it to be a part of unpack_sha1_header?

Just to reduce the number of functions and the complexity of the caller.
But I guess it doesn't help that much if the caller would then need to
speculatively pass in a strbuf. So it's probably not a good idea.

-Peff