Messages in this thread | | | Subject | Re: [RFC PATCH v2] mm: slub: print kernel addresses in slub debug messages | From | Miles Chen <> | Date | Fri, 9 Aug 2019 22:11:58 +0800 |
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On Thu, 2019-08-08 at 19:46 -0700, Matthew Wilcox wrote: > On Fri, Aug 09, 2019 at 09:08:37AM +0800, miles.chen@mediatek.com wrote: > > Possible approaches are: > > 1. stop printing kernel addresses > > 2. print with %pK, > > 3. print with %px. > > No. The point of obscuring kernel addresses is that if the attacker manages to find a way to get the kernel to spit out some debug messages that we shouldn't > leak all this extra information.
got it. > > > 4. do nothing > > 5. Find something more useful to print.
agree > > > INFO: Slab 0x(____ptrval____) objects=25 used=10 fp=0x(____ptrval____) > > ... you don't have any randomness on your platform?
We have randomized base on our platforms.
> But if you have randomness, at least some of these "pointers" are valuable > because you can compare them against "pointers" printed by other parts > of the kernel.
Understood. Keep current %p, do not leak kernel addresses.
I'll collect more cases and see if we really need some extra information. (maybe the @offset in current message is enough)
thanks for your comments!
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