Re: [dpdk-dev] [PATCH] librte_cmdline: FreeBSD Fix oveflow when size of command result structure is greater than BUFSIZ

[Olivier MATZ <olivier.matz@6wind.com>]

Hello Alan,

On 10/20/2014 05:26 PM, Carew, Alan wrote:
> A comment on my own patch.
> 
> Making the size of result_buf consistent across each OS and keeping it as large
> as the Linux BUFSIZ(8192) doesn't really address the core issue.
> 
> In the event that a user of librte_cmdline creates a custom context with a
> result structure > 8192 bytes then this problem will occur again, though 
> somewhat unlikely, as the minimum number of the largest type would be 64 x 
> cmdline_fixed_string_t types within a result structure, at its current size.
> 
> There is no checking of overflow, I would be tempted to add a runtime check in
> cmdline_parse()/match_inst(), however I would be more comfortable with a build
> time check for this type of problem.
> 
> Due to the opaque handling of user defined contexts there is no obvious way to
> do this at build time.
> 
> Thoughts?

Indeed, your patch does not address the core issue of the problem,
altough it's already an improvement to the current situation.

Your issue was already fixed in the latest libcmdline library by
this patch (which also includes the replacement of BUFSIZ):
http://git.droids-corp.org/?p=libcmdline.git;a=commitdiff;h=b1d5b169352e57df3fc14c51ffad4b83f3e5613f

I'm pretty sure it won't apply smoothly on the dpdk command line
library but it can probably be adapted. Ideally, the latest libcmdline
library should be [cleaned first and] merged in dpdk.org.

Regards,
Olivier