Messages in this thread | | | Date | Mon, 27 Jun 2016 21:32:20 +0300 | From | Jarkko Sakkinen <> | Subject | Re: [PATCH] tpm: vtpm_proxy: Introduce flag to prevent sysfs entries |
| |
On Fri, Jun 24, 2016 at 02:43:00PM -0400, Stefan Berger wrote: > On 06/24/2016 01:48 PM, Jason Gunthorpe wrote: > >On Fri, Jun 24, 2016 at 10:36:55AM -0400, Stefan Berger wrote: > >>Introduce TPM_VTPM_PROXY_NO_SYSFS flag that prevents a vtpm_proxy driver > >>instance from having the typical sysfs entries that shows the state of the > >>TPM. The flag is to be set in the ioctl creating the vtpm_proxy device > >>pair and maps on a new chip flags TPM_CHIP_FLAG_NO_SYSFS. > >No other subsystem does something so goofy, this really needs to be > >part of namespace support for TPM. > > And I am not sure how to go about this. TPM2 by the way doesn't have such > entries, so it's much better from that perspective. > > > > >Why can't you just make the sysfs files unreadable in user space? > > There are actually ways to go about this. Likely bind-mounting over > /sys/device/virtual/tpm would be one solution to hide all virtual TPM > device. Another is applying an AppArmor policy to the container denying > access to tpm directories or entries. SELinux would not be so easy. > > The flag in this patch seemed like a 'cheap' way to eliminate that problem > as well.
Does it have any other qualities that would make this better than bind mounting?
/Jarkko
| |