On Mon, 2020-08-24 at 22:44 +0300, Jarkko Sakkinen wrote: > On Fri, Aug 21, 2020 at 04:38:47PM -0300, Jason Gunthorpe wrote: > > On Thu, Aug 20, 2020 at 09:14:44AM -0700, James Bottomley wrote: > > > > > > eg we can't do it because we can't access /dev/tpm for > > > > permissions or > > > > something. > > > > > > I already said that: we can't it's root.root 0600 currently. All > > > the TSSs seem to change at least /dev/tpmrm to tpm.tpm 0660 but > > > we can't do that in the kernel because there's no fixed tpm > > > uid/gid. > > > > Permissions is a pretty good reason to add a sysfs file. > > > > Jason > > I'm not sure why suid/sgid utility to read pcrs would be worse. We don't do root running or suid/sgid binaries any more because they're exceptional security risks. That's why both TSSs for TPM 2.0 change the device ownership. For Trousers and TPM 1.2 we used to run the daemon as root until we started getting CVEs about it. James
