Re: [PING][PATCH] [RFCv2] Document Security process for binutils

[Siddhesh Poyarekar <siddhesh@gotplt.org>]

On 1/19/21 1:57 PM, Alan Modra wrote:
> If you are serious about security then "don't run any of binutils as
> root" is sufficient advice.  I don't think any of this documentation
> in info files is necessary for binutils, and I'd rather not see more
> people fuzzing binutils.
> 
> As someone who has spent rather a lot of time over the past year
> responding to asan, ubsan, and fuzzed object file bug reports, I can
> tell you that the great majority of those reports do not fix real
> bugs.  By "real bugs", I mean bugs that might conceivably be triggered
> by real object files created by compilers or assemblers.

What you said basically implies that running binutils tools in anything 
other than a fully trusted environments is unsupported, which eliminates 
all usage of binutils tools where they may be invoked remotely.

Also, running as root is not the only vector.  For example, one could in 
theory achieve remote code execution if binutils is invoked on untrusted 
binaries remotely.  It could either be directly through a service or by 
chaining with another bug that causes generation or storage of invalid 
binaries.

> Yes, we do have libbfd and libopcodes that are used by more than just
> binutils and gdb, but the number of projects is small.

Unfortunately that number is not zero and it is conceivable that the 
libraries may be used in an untrusted context.

The effect of such documentation is to clearly define usage patterns 
that will be accepted as CVE-worthy and as a result, limit them 
considerably.  In that sense, we're on the same team!

Perhaps explicitly stating that "Bugs in binutils that need tools to be 
run as root to be locally exploitable will be treated as regular bugs 
and not as security flaws" is a worthy addition?  Are there any other 
constraints for considering bugs as security issues that you can think 
of?  We could keep adding those as we go along.

Thanks,
Siddhesh