Hardened Malloc - Hardened Memory Allocator

[Patrick]

@HulaHoop

From Tom’s reply I understand that the attacker needs to be in a privileged position on your system to fingerprint the allocator, one similar to fingerprinting the CPU and RAM behavior. An attacker with that much power can do much more damage than merely fingerprint. This doesn’t apply to run of he mill websites anyone visits.

I didn’t reach the same conclusion.

[tor-dev] TBB Memory Allocator choice fingerprint implications starts with:

Writes early…

Fingerprinting: It is most likely possible to be creative enough to fingerprint what memory allocator is used.

Does not state what local exploitation is a prerequisite. If this matters, please quote the passages which lead to the conclusion and/or ask him to clarify this very point.

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https://lists.torproject.org/pipermail/tor-dev/2019-August/013982.html

LD_PRELOAD=‘/path/to/libhardened_malloc.so’ /path/to/program will do
nothing or approximately nothing.

Reason enough to disable hardened malloc for Tor Browser when using tb_hardening=true. Will work on that.

harden_malloc definitely has more bells and whistles than mozjemalloc.
But the benefit gained by slapping in an LD_PRELOAD and calling it a
day is small to zero. Probably negative because you’ll not utilize
partitions by default.

More reason to do so.