13

If I systemless root (no modification done to /system partition) a nexus device, would I be able to able to set capabilites on executables without changing the original kernel binary ?

I often want to manage files without restrictions from my terminal (requireCAP_DAC_READ_SEARCH). however, I also want to not use the superuser.
The required things are tools for setting caps along kernel support for using them (it doesn’t relies on other user space things).

The problem is, I don’t own such device. So I can’t tell if it would work on any of Nexus 5X Nexus 6P Nexus 9 Pixel C.

  • 2
    I was also unable to find a nexus emulator… – user2284570 Apr 11 '16 at 21:15
  • I doubt it... Since Android uses Bionic libc and not the standard GNU libc (glibc) library, it is not even close to POSIX compliant. You might be able to compile your own kernel with a different libc like CrystaX NDK instead of Bionic, but I don't know if those features are in that either. – acejavelin Apr 12 '16 at 0:54
  • @acejavelin : the userland part is only required for setting extended attributes containing capabilities. Everything else is kernel side. I just noticed the/system/bin/pingcommand isn’t setuid on my real samsung device, suggestingCAP_NET_RAW. However, I won’t root a real device and I don’t know which tool I can use to see the relevant informations, so I can’t check. – user2284570 Apr 12 '16 at 1:02
  • Why would you not root a Nexus device? It is intended for that and does not void your warranty. It is very simple to restore any Nexus device to it's default, unrooted and locked state, the device is basically unbrickable. – acejavelin Apr 12 '16 at 1:05
  • @acejavelin : I don’t own a nexus device… My aim is security research and google only reward for it’s own devices. So I need to know if the kernel of one of the devices in my question support using capabilities xattr. What I’m seeing on my galaxy tab is probably only samsung related. If I don’t involve rooting in my question it might be closed as unclear. – user2284570 Apr 12 '16 at 1:21

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.