Arm Backporting SLS Vulnerability Mitigation To Existing GCC Releases

[phoronix]

Phoronix: Arm Backporting SLS Vulnerability Mitigation To Existing GCC Releases

Back in June when Arm disclosed their Straight Line Speculation (SLS) vulnerability affecting their modern ARM processor designs there wasn't a whole lot of attention. It seems SLS is serious enough that Arm is working on bringing their compiler-based mitigations to existing GCC releases beyond it already being in the current development code...

http://www.phoronix.com/scan.php?page=news_item&px=Arm-SLS-GCC-Backporting

[lucrus]

Now given a random smartphone (let's assume it's Android), how do you find out if it's vulnerable?

Here is my guess (but keep in mind, it's just a guess):

1. Install Droid Info, that shows what Arm CPU the smartphone has.
2. Open the app, look for the "System" tab
3. Find the "Instructions set" item. If it contains "v8" in the value, your smartphone is vulnerable.

Can anyone confirm this is a correct way yo know?
Assuming it is, next question is how hard can it be for an application to exploit this vulnerability and what kind of data it can steal.

[hotaru]

Now given a random smartphone (let's assume it's Android), how do you find out if it's vulnerable?

Here is my guess (but keep in mind, it's just a guess):

1. Install Droid Info, that shows what Arm CPU the smartphone has.
2. Open the app, look for the "System" tab
3. Find the "Instructions set" item. If it contains "v8" in the value, your smartphone is vulnerable.

Can anyone confirm this is a correct way yo know?
Assuming it is, next question is how hard can it be for an application to exploit this vulnerability and what kind of data it can steal.

nope, not correct. there are ARMv8 cores that aren't vulnerable because they don't do speculative execution (Cortex-A32, Cortex-A35, Cortex-A53, and Cortex-A55). there are also ARMv7 cores that do speculative execution, which might be vulnerable.

[lucrus]

nope, not correct. there are ARMv8 cores that aren't vulnerable because they don't do speculative execution (Cortex-A32, Cortex-A35, Cortex-A53, and Cortex-A55). there are also ARMv7 cores that do speculative execution, which might be vulnerable.

Thank you very much... and... what's the correct way to tell if my smartphone is vulnerable then?

[hotaru]

Thank you very much... and... what's the correct way to tell if my smartphone is vulnerable then?

look at what cores your phone has and search online to find out if they're in-order or out-of-order. if they're in-order, they're not vulnerable. if they're out-of-order, they're probably vulnerable. most smartphones have both in-order and out-of-order cores.

[Guest]

Now given a random smartphone (let's assume it's Android), how do you find out if it's vulnerable?

Here is my guess (but keep in mind, it's just a guess):

1. Install Droid Info, that shows what Arm CPU the smartphone has.
2. Open the app, look for the "System" tab
3. Find the "Instructions set" item. If it contains "v8" in the value, your smartphone is vulnerable.

Can anyone confirm this is a correct way yo know?
Assuming it is, next question is how hard can it be for an application to exploit this vulnerability and what kind of data it can steal.

Almost every single Android phone/tablet and iOS phone/tablet/watch released in the past few years has an ARMv8 CPU.

I wonder if the final Android 10 update for my OnePlus 5 was built with a mitigated compiler? Or is it now vulnerable as long as I'm using the official OS.