[PATCH 0/5] kallsyms: make kallsym APIs more safe with scnprintf

Kees Cook keescook at chromium.org
Tue May 24 05:39:12 AEST 2022


On Sat, May 21, 2022 at 11:07:52PM -0700, Christoph Hellwig wrote:
> On Fri, May 20, 2022 at 02:06:56PM +0530, Maninder Singh wrote:
> > kallsyms functionality depends on KSYM_NAME_LEN directly.
> > but if user passed array length lesser than it, sprintf
> > can cause issues of buffer overflow attack.
> > 
> > So changing *sprint* and *lookup* APIs in this patch set
> > to have buffer size as an argument and replacing sprintf with
> > scnprintf.
> 
> This is still a pretty horrible API.  Passing something like
> a struct seq_buf seems like the much better API here.  Also with
> the amount of arguments and by reference passing it might be worth
> to pass them as a structure while you're at it.

Yeah, I agree. It really seems like seq_buf would be nicer.

-- 
Kees Cook


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