[PATCH] D70762: scudo: Add initial memory tagging support.

[Peter Collingbourne via Phabricator via llvm-commits]

pcc added a comment.

In D70762#1762324 <https://reviews.llvm.org/D70762#1762324>, @hctim wrote:

> > The granules
> >  either side of the allocation are tagged with tag 0, which is normally
> >  excluded from the set of tags that may be selected randomly
>
> It seems valuable to have the LHS and RHS of an allocation as a nonzero tag. IIUC, the chunk header is on the LHS for primary allocations, and making the header MTE-protected (the tag can be stored in the Primary allocator struct somewhere) seems like a good additional security step to make it unwriteable from a deterministic (zeroed) pointer.


It's already protected by using tag 0, which we don't use in heap pointers, so I'm not sure what your concern is.


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  https://reviews.llvm.org/D70762/new/

https://reviews.llvm.org/D70762