On Mon, Feb 12, 2024 at 12:48 PM Stefan Berger <[email protected]> wrote:
> On 1/15/24 13:18, Roberto Sassu wrote:
..
> > +/**
> > + * ima_kernel_module_request - Prevent crypto-pkcs1pad(rsa,*) requests
> > + * @kmod_name: kernel module name
> > + *
> > + * We have situation, when public_key_verify_signature() in case of RSA > + * algorithm use alg_name to store internal information in order to
> > + * construct an algorithm on the fly, but crypto_larval_lookup() will try
> > + * to use alg_name in order to load kernel module with same name.
> > + * Since we don't have any real "crypto-pkcs1pad(rsa,*)" kernel modules,
> > + * we are safe to fail such module request from crypto_larval_lookup().
> > + *
> > + * In this way we prevent modprobe execution during digsig verification
> > + * and avoid possible deadlock if modprobe and/or it's dependencies
> > + * also signed with digsig.
>
> This text needs to some reformulation at some point..
There is no time like the present. If you have a suggestion I would
love to hear it and I'm sure Roberto would too.
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paul-moore.com