Re: [PATCH net 1/2] ipv4: mcast: getsockopt: do not overwrite past optlen

On Tue, 11 Aug 2026 05:19:17 -0700 Breno Leitao wrote:
> So my question to you: can you point me to actual software that
> passes a "small" optlen and expects the kernel to write past it? That
> would help to decide about the two options above.

If you are very confident that no such SW exists - we can try to queue
this up for -next. (TBH I'm not, mcast specifically may be full of
strange one off manually written user space (as opposed to common libraries)).

If we decide to change the behavior- we will probably have to wait
until this makes it to an LTS release + some time for people to deploy.
It can't be a fix.

So practically speaking it may be more expedient to add some hacks to
cater to this case in the conversion, and then remove the hack. That'd
be easier to revert if someone pipes up later that we broke their SW.