Messages in this thread | | | Date | Fri, 17 Dec 2010 17:22:31 -0800 | From | Andrew Morton <> | Subject | Re: [PATCH v2] kptr_restrict for hiding kernel pointers from unprivileged users |
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On Fri, 17 Dec 2010 20:12:39 -0500 Dan Rosenberg <drosenberg@vsecurity.com> wrote:
> > > > So what's next? We need to convert 1,000,000 %p callsites to use %pK? > > That'll be fun. Please consider adding a new checkpatch rule which > > detects %p and asks people whether they should have used %pK. > > The goal of this format specifier is specifically for pointers that are > exposed to unprivileged users. I agree that hiding all kernel pointers > would be nice, but I don't expect the angry masses to ever agree to > that. For now, I'll isolate specific cases, especially in /proc, that > are clear risks in terms of information leakage. I'll also be skipping > over pointers written to the syslog, since I think hiding that > information is dmesg_restrict's job.
Well... some administrators may wish to hide the pointer values even for privileged callers. That's a pretty trivial add-on for the code which you have, and means that those admins can also suppress the pointers for IRQ-time callers. More /proc knobs :)
Then again, perhaps those admins would be OK if we simply disabled plain old %p everywhere. In which case we're looking at a separate patch, I suggest.
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