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Fai0verflow: Linux on the PS4 [video]

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Re: Fai0verflow: Linux on the PS4 [video]

#21

Post by derefr »

jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

As consoles get more and more powerful and introduce abstractions between the game developer and the hardware (kernels, syscalls, platform runtime libraries), I've figured it would only be a matter of time before we stop trying to emulate the way that console works, and instead begin to virtualize the console by writing API-compatible wrapper libraries.

Presuming developers just treat the PS4 as somewhat like we treat PCs: a generic processor that can do "math stuff", and some black-box libraries for {threading, graphics, audio, HID support, networking, ...}, then it becomes far easier to statically recompile a PS4 binary into a native PC binary: just recompile the "math stuff" for your target architecture, and then replace the linkages to libraries provided by the PS4 SDK, to libraries provided by your virtualization wrapper.

In other words, basically do the equivalent of what Emscripten does to C programs that expect to use OpenGL: compile the C to asm.js, and compile the calls OpenGL into calls to WebGL.

Re: Fai0verflow: Linux on the PS4 [video]

#22

Post by zingermc »

jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

Since the PS4 OS is based on FreeBSD, you could conceivably match up parts of the compiled PS4 kernel with FreeBSD source code. However, I bet there's some sort of obfuscation that their compiler performs to make it difficult to decompile.

Re: Fai0verflow: Linux on the PS4 [video]

#24

Post by SXX »

jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

It's feasible, but to make firmware useful outside of device encryption keys must be extracted or firmware need to be heavily patched. Both tasks are complex and there not many people that going to work on it because groups like fail0verflow don't support piracy.

Also video does show privilege escalation that start via webkit exploit, but that doesn't mean that they worked towards breaking of content encryption and / or dumping games.

Re: Fai0verflow: Linux on the PS4 [video]

#25

Post by vvanders »

derefr wrote: post #21
jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

As consoles get more and more powerful and introduce abstractions between the game developer and the hardware (kernels, syscalls, platform runtime libraries), I've figured it would only be a matter of time before we stop trying to emulate the way that console works, and instead begin to virtualize the console by writing API-compatible wrapper libraries. Presuming developers just treat the PS4 as somewhat like we trea…

Talk to some game devs sometimes, they don't think of it like a PC at all(which is why PC -> console is so hard and not vice versa).

I doubt we'll ever see this for titles that extract every ounce of performance out of a platform.

Re: Fai0verflow: Linux on the PS4 [video]

#26

Post by user583495234 »

derefr wrote: post #21
jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

As consoles get more and more powerful and introduce abstractions between the game developer and the hardware (kernels, syscalls, platform runtime libraries), I've figured it would only be a matter of time before we stop trying to emulate the way that console works, and instead begin to virtualize the console by writing API-compatible wrapper libraries. Presuming developers just treat the PS4 as somewhat like we trea…

You just re-invented high-level emulation. See UltraHLE from 1999.

Re: Fai0verflow: Linux on the PS4 [video]

#27

Post by balls187 »

m00dy wrote: post #3

Actually, I was expecting more technical stuff relating to how they jailbreak the system. PoC is also good though.

(from the video)

It looked like they found an exploit via whatever app renders the userguide.html

Curious if they used a proxy to instead load a "malicious" page resulting in a buffer-overflow.

Re: Fai0verflow: Linux on the PS4 [video]

#28

Post by guipsp »

balls187 wrote: post #27
m00dy wrote: post #3

Actually, I was expecting more technical stuff relating to how they jailbreak the system. PoC is also good though.

(from the video) It looked like they found an exploit via whatever app renders the userguide.html Curious if they used a proxy to instead load a "malicious" page resulting in a buffer-overflow.

webkit, and yes, probably

Re: Fai0verflow: Linux on the PS4 [video]

#29

Post by mbilker »

virtuallynathan wrote: post #5
mmastrac wrote: post #2

There doesn't appear to be much info about this other than it's a Linux 'kexec-like' from a webkit bug that apparently triggers a kernel exploit. Awesome job!

Some of this has been covered in other blogs: https://cturt.github.io/ps4.html

That blog detailed the WebKit exploit and how they used it to get information about the PS4's base system.

The fail0verflow exploit takes it a step further to "kexec" the system into linux where the linux system has direct access to the hardware.

Re: Fai0verflow: Linux on the PS4 [video]

#30

Post by mbilker »

zingermc wrote: post #22
jaimehrubiks wrote: post #18

Would it be possible to achieve the opposite in some way?, I mean, dump the kernel and build it on a pc on top of a compatible hardware? Let me know what you think

Since the PS4 OS is based on FreeBSD, you could conceivably match up parts of the compiled PS4 kernel with FreeBSD source code. However, I bet there's some sort of obfuscation that their compiler performs to make it difficult to decompile.

Apparently there are very little changes in the Sony PS4 kernel compared to FreeBSD 9. Sony changed some of the parameters to syscalls and added a bunch of their own syscalls.
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