Google says Rowhammer attacks are gaining range as RAM is getting denser

So it sounds like security related flags need to be more than a single bit, and should probably be stored in different variables

The problem isn't RowHammer, the problem is lack of ECC. This is mostly Intel's fault, as they cripple their consumer CPU lines to disable ECC for market segmentation purposes.

The entire premise that we can store tens of gigabytes of information reliably in tiny silicon capacitors without any error detection or correction whatsoever is ludicrous. Every other storage technology uses advanced error correction - NAND Flash, HDDs, optical media, etc. We've been doing this for decades. Even floppies at least had error detection (checksums). All high speed transmission protocols also do error detection and re-transmission, except HDMI (because I guess nobody cares about the odd corrupted pixel). Same for anything going over radio.

Once you have ECC, your error rate margin goes up by many orders of magnitude. Worst case these attacks turn into a DoS as ECC fails to correct a badly corrupted word, and most of the time it will just work. Plus you can detect attack attempts as the memory controller will report increased error rates.

It's not possible to design modern RAM that is perfectly reliable. That's just physics. We know how to solve this problem. We just aren't doing it because Intel thinks consumers don't deserve reliable RAM. The only other option is doing ECC on-chip in the RAM itself, and that has other efficiency trade-offs which probably make it not worth it, at least not with DDR style interfaces (it might've made sense in an FB-DIMM style world where the memory controller is in the RAM)

Last time I tested such things, they handled ECC correctly (x86 and arm).

Chrome gave me a segfault crash message I've never seen before by simply visiting youtube this morning.

I thought for a moment what the most likely explanation was, given Chrome has surely seen a boatload of stability testing. It's a sandbox viewing a website. A segfault?!

I wonder if it's cosmic rays on my non ECC RAM or some accidental rowhammer moment.

ECC is at best a temporary workaround, and at worst an implicit approval of the creation of defective products. It's purpose is to prevent transient bitflips due to cosmic rays and such, not consistently reproducible errors from what is otherwise perfectly normal operation.

Plus you can detect attack attempts as the memory controller will report increased error rates.

Now you've turned specific access patterns into "attack attempts", and by discriminating against them as such, entirely destroyed a fundamental part of general-purpose computing. What's next, CPUs that are only guaranteed to do certain operations correctly, and everything else is considered an "attack"? That is NOT a direction that we should be heading. Hell fucking no!!!

RAM should always hold what was last written to it, under all conditions of software accesses. To expect or imply that anything less is acceptable, is to destroy one of the foundations on which general-purpose computing is built.

NAND Flash

Where manufacturers are trying to sell 2-4x the capacity with 1/4 to 1/16th of the endurance? That's a rant for another thread...

We know how to solve this problem.

This problem didn't exist 15 years ago. It only got created because the RAM companies have forsaken correctness, and somehow managed to convince everyone else that it's not their own fault.