Re: [PATCH] net: Initialize ctx to avoid memory allocation error

From: Florian Westphal
Date: Fri Mar 14 2025 - 12:47:45 EST


Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> If seclen is 0 it implies that there is no security context and that
> the secctx is NULL. How that is handled in the release function is up
> to the LSM. SELinux allocates secctx data, while Smack points to an
> entry in a persistent table.
>
> > seclen needs to be > 0 or no secinfo is passed to userland,
> > yet the secctx release function is called anyway.
>
> That is correct. The security module is responsible for handling
> the release of secctx correctly.
>
> > Should seclen be initialised to -1? Or we need the change below too?
>
> No. The security modules handle secctx their own way.

Well, as-is security_release_secctx() can be called with garbage ctx;
seclen is inited to 0, but ctx is not initialized unconditionally.