Marcan of the Fail0verflow hacking group just published a lengthy article on the Fail0verflow blog, where he gives details about their approach for porting Linux on the PS4.

Yesterday, the Fail0verflow group announced to the world that they got Linux up and running on the PS4. They demoed a PS4 running Linux, and launched an emulator to play Pokémon on the PS4. Fail0verflow had previously hacked the original Wii, the PS3, and the Wii U (although they never released their work for the Wii U).

Linux on the PS4: We’re trying something new

The famous group of hackers was disappointed in how the scene reacted to their PS3 exploit release, as they feel it basically led only to piracy and not a striving Homebrew scene. This is why they decided to not release their Wii U hack two years ago. But there again, they saw that others released exploits, which according to Fail0verflow led mostly to piracy.

Their approach for the PS4, they state, will be to release a functioning port of Linux for the system, not exploits. This confirms what they stated in their presentation yesterday: Fail0verflow are working on providing the PS4 hacking scene with a great OS to experiment with, but other hackers will have to provide the exploits.

Fail0verflow’s official goal by doing that is to try and steer the community’s interest in favor of Linux and Indie development, rather than piracy. By providing a fully working OS on the PS4, they hope, hackers will not dive into reverse engineering some parts that are critical for piracy, and where Linux will not help.

This is a nice idea. In reality, I’m sure this will only work for a portion of hackers. There are groups out there that have financial benefits in enabling piracy on any console, and these people will be the ones working on removing the locks from official game DRMs. And, really, it only takes one group to enable piracy, while it will take huge efforts from the scene to promote “clean” use of the platform.

On the Wii, we basically drove the entire homebrew community, from exploits to libraries to infrastructure. The community ended up being very large and productive, with lots of interesting releases. However, the people interested in game piracy were always riding on the coattails of homebrew since relatively early on, and greatly benefited from it.

On the PS3 , we tried releasing the exploits and letting others sort out the community. The result was that, for all practical purposes, the only users were those interested in piracy. AsbestOS allowed Linux to work again, but since there was no GPU driver, and the CPU was underpowered and annoying to work with, there wasn’t that much interest beyond those who were already running OtherOS.

, we tried releasing the exploits and letting others sort out the community. The result was that, for all practical purposes, the only users were those interested in piracy. AsbestOS allowed Linux to work again, but since there was no driver, and the was underpowered and annoying to work with, there wasn’t that much interest beyond those who were already running OtherOS. On the Wii U, we tried to get the community to display interest and work on Linux support before releasing the exploits. Although there were certainly several interested people, nobody with the right experience stepped up to actually make it a reality. Eventually others released exploits, and quickly a piracy tool has become one of the primary use cases for them. For the PS4, therefore, we’re yet again trying something new.

SteamOS on the PS4 should “just work”

Despite my doubts about the final outcome, I like the approach here. As Marcan states, “Linux on the PS4 makes sense”. It would provide a full platform for game development, and, more importantly, would open the PS4 to competitive prices, just as can be seen on other platforms. Specifically, one could use their PS4 to run SteamOS, meaning access to a huge library of games and some more competition on digital prices. This could be good. In an ideal world, piracy would not rise from the hacks, and the main purpose for hackers would be to enable an alternate OS and other digital game stores to work, one of the few accepted reasons to Jailbreak a device.

Linux on the PS4 actually makes a lot of sense, more than it ever did on any previous game console. It’s close enough to a PC that getting 3D acceleration working, while rather painful (as we’ve learned), seems entirely possible without undue amounts of effort (in a timeframe of months, not years), to the level needed for real indie games and even AAA titles, not just homebrew. And many thousands of indie and AAA games already run on Linux. Yes, SteamOS on the PS4 should “just work” once the driver issues are sorted out.

For now though, the Fail0verflow crew need to iron out bugs and work on drivers. It’s going to “take months, not years” though, which is good news.

PS4 Exploit release?

Failverflow have no intent to release their exploit, but we also know several groups have reached Kernel access on the device. The question of course is if the Linux on PS4 announce changes any decision to not release any exploit.

There’s some level of hope here: “We also have no doubt that vulnerabilities in the latest firmware can be found without too much trouble”, Marcan said.

A side note: I have said the exploit used for the demonstration yesterday might have been hardware based. Marcan has confirmed that this was not the case. It now appears they have used the Webkit 1.76 exploit as an entrypoint, and some FreeBSD vulnerability for Kernel access. The fact that they use a 1.76 user level exploit on Webkit does not mean however that their Kernel hack would not run on a higher firmware. As a reminder, and to dumb it down, one basically needs two exploits: the first one to hijack a process (e.g. webkit), and a second one to get root privilege.

Incidentally, everything is pure software. Hardware stuff was only used for research. There is not much reason to resort to hardware-based exploits on an architecture like the PS4, with a very wide attack surface and mediocre isolation.

Again, Fail0verflow themselves will not release any exploit, but there might be hopes that another hacking crew will step up once the Linux port is polished.

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