Hi! > > > > > As security becomes more and more important, we add the in-kernel > > > > > encryption support for hibernation. > > > > > > > > Sorry, this does not really explain what security benefit it is > > > > supposed have to against what attack scenarios. > > > > > > > > Which unfortunately means it can not reviewed. > > > > > > > > Note that uswsusp already provides encryption. If this is supposed to > > > > have advantages over it, please say so. > > > > > > > The advantages are described in detail in > > > [PATCH 1/4]'s log, please refer to that. > > > > Are you refering to this? > > > Not this one. I've sent v2 of this patch set which > explain more on this: > https://patchwork.kernel.org/patch/10532935/ Aha, sorry about that. > Let me paste the log here: > > 1. (This is not to compare with uswsusp but other > tools) One advantage is: Users do not have to > encrypt the whole swap partition as other tools. Well.. encrypting the partition seems like good idea anyway. > 2. Ideally kernel memory should be encrypted by the > kernel itself. We have uswsusp to support user > space hibernation, however doing the encryption > in kernel space has more advantages: > 2.1 Not having to transfer plain text kernel memory to > user space. Per Lee, Chun-Yi, uswsusp is disabled > when the kernel is locked down: > https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/ > linux-fs.git/commit/?h=lockdown-20180410& > id=8732c1663d7c0305ae01ba5a1ee4d2299b7b4612 > due to: > "There have some functions be locked-down because > there have no appropriate mechanisms to check the > integrity of writing data." > https://patchwork.kernel.org/patch/10476751/ So your goal is to make hibernation compatible with kernel lockdown? Do your patches provide sufficient security that hibernation can be enabled with kernel lockdown? > 2.2 Not having to copy each page to user space > one by one not in parallel, which might introduce > significant amount of copy_to_user() and it might > not be efficient on servers having large amount of DRAM. So how big speedup can be attributed by not doing copy_to_user? > 2.3 Distribution has requirement to do snapshot > signature for verification, which can be built > by leveraging this patch set. Signatures can be done by uswsusp, too, right? > 2.4 The encryption is in the kernel, so it doesn't > have to worry too much about bugs in user space > utilities and similar, for example. Answer to bugs in userspace is _not_ to move code from userspace to kernel. > > Also note that joeyli <jlee@xxxxxxxx> has patch series which encrypts > > both in-kernel and uswsusp hibernation methods. His motivation is > > secure boot. How does this compare to his work? > > > Joey Lee and I had a discussion on his previous work at > https://patchwork.kernel.org/patch/10476751 > We collaborate on this task and his snapshot signature > feature can be based on this patch set. Well, his work can also work without your patchset, right? Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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