Messages in this thread | | | From | Dan Williams <> | Date | Tue, 19 Mar 2019 16:01:51 -0700 | Subject | Re: [PATCH] security/keys/trusted: Allow operation without hardware TPM |
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On Tue, Mar 19, 2019 at 3:56 PM Mimi Zohar <zohar@linux.ibm.com> wrote: > > Hi Dan, > > On Mon, 2019-03-18 at 17:30 -0700, Dan Williams wrote: > > Sorry for the late reply. > > > On Mon, Mar 18, 2019 at 5:24 PM James Bottomley <jejb@linux.ibm.com> wrote: > > > > > > On Mon, 2019-03-18 at 16:45 -0700, Dan Williams wrote: > > > > Rather than fail initialization of the trusted.ko module, arrange for > > > > the module to load, but rely on trusted_instantiate() to fail > > > > trusted-key operations. > > > > > > What actual problem is this fixing? To me it would seem like an > > > enhancement to make the trusted module fail at load time if there's no > > > TPM rather than waiting until first use to find out it can never work. > > > Is there some piece of user code that depends on the successful > > > insertion of trusted.ko? > > > > The module dependency chain relies on it. If that can be broken that > > would also be an acceptable fix. > > > > I found this through the following dependency chain: libnvdimm.ko -> > > encrypted_keys.ko -> trusted.ko. > > > > "key_type_trusted" is the symbol that encrypted_keys needs regardless > > of whether the tpm is present. > > Commit 982e617a313b ("encrypted-keys: remove trusted-keys dependency") > removed the dependency on trusted keys. masterkey_trusted.c should > only be included if "CONFIG_TRUSTED_KEYS" is enabled. Is > CONFIG_TRUSTED_KEYS enabled?
Yes, TRUSTED_KEYS is enabled, the module is built/available, and tries to load when encrypted_keys.ko loads. The problem is that it fails to load due an error returned from init_trusted(). The error is new for v5.1. So, instead of requiring the module dependencies to resolve successfully, and init_trusted() to return 0, the proposal is to just lookup the key types by name.
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