Adding to the discussion Jarkko (the maintainer of the trusted key) and the linux-integrity mailing list. On 6/27/2019 7:59 PM, CrazyT wrote:
Hi, some people (including me) have problems with the "trusted" kernel module. As a result to this also the ecryptfs-module won't load. (https://bugs.archlinux.org/task/62678) If you use an "inactive" TPM module, the "trusted" module won't load anymore. The command modprobe just responds with "Bad address". The strace-command shows that init_module fails with EFAULT. I believe the reason for this is that the trusted-module handles inactive modules the same as active modules. This results in an error. For example: https://github.com/torvalds/linux/commit/0b6cf6b97b7ef1fa3c7fefab0cac897a1c4a3400#diff-c01228e6d386afb29df6aac17d9dd7abR1251 My guess is that init_digests(); returns EFAULT in that case. The " if (!chip)" check above probably needs to check if the chip is "inactive". "inactive" = still visible to the system, but not functional. It seems to be the default bios-setting for TPM on thinkpad. (btw.: i have no clue why anybody would need something like that) Sadly i have no idea how you would check for an inactive chip,else i would have send a patch instead. But I hope the info i wrote is enough to get it fixed by somebody.
Thanks for the report. If you see -EFAULT, tpm_get_random() is probably returning 0. Jarkko, we could consider it as non-critical error, and handle it as if the TPM is not found. What do you think? Roberto -- HUAWEI TECHNOLOGIES Duesseldorf GmbH, HRB 56063 Managing Director: Bo PENG, Jian LI, Yanli SHI
