On Fri, 17 May 2024 at 03:59, James Bottomley <james.bottom...@hansenpartnership.com> wrote: > > On Thu, 2024-05-16 at 20:25 -0400, Nícolas F. R. A. Prado wrote: ... > > KernelCI has identified a new warning and I tracked it down to this > > commit. It > > was observed on the following platforms: > > * mt8183-kukui-jacuzzi-juniper-sku16 > > * sc7180-trogdor-kingoftown > > (but probably affects all platforms that have a tpm driver with async > > probe) > > > > [ 2.175146] Call trace: > > [ 2.177587] __request_module+0x188/0x1f4 > > [ 2.181596] crypto_alg_mod_lookup+0x178/0x21c > > [ 2.186042] crypto_alloc_tfm_node+0x58/0x114 > > [ 2.190396] crypto_alloc_shash+0x24/0x30 > > [ 2.194404] drbg_init_hash_kernel+0x28/0xdc > > [ 2.198673] drbg_kcapi_seed+0x21c/0x420 > > [ 2.202593] crypto_rng_reset+0x84/0xb4 > > [ 2.206425] crypto_get_default_rng+0xa4/0xd8 > > [ 2.210779] ecc_gen_privkey+0x58/0xd0 > > [ 2.214526] ecdh_set_secret+0x90/0x198 > > [ 2.218360] tpm_buf_append_salt+0x164/0x2dc > > This looks like a misconfiguration. The kernel is trying to load the > ecdh module, but it should have been selected as built in by this in > drivers/char/tpm/Kconfig: > > config TCG_TPM2_HMAC > bool "Use HMAC and encrypted transactions on the TPM bus" > default y > select CRYPTO_ECDH > select CRYPTO_LIB_AESCFB > select CRYPTO_LIB_SHA256 >
The module request is not for ECDH itself but for the DRBG it attempts to use to generate the secret. Given that CRYPTO_ECDH does not strictly require a DRBG in principle, but does in this particular case, I think it makes sense to select CRYPTO_DRBG here (or depend on it being builtin), rather than updating the Kconfig rules for CRYPTO_ECDH itself.
