Will DormannDec 9, 2024

Back when I was poking around with filesystem fuzzing stuff years back, I noticed something odd:

An EXT filesystem can tell the Linux OS how it should behave "if" the filesystem is corrupt, including triggering a kernel panic. In a world where USB thumb drives exist, this seems... not ideal.

Let's see what happens if we plug such a mass storage device into a fully patched Chromebook in 2024...

Oh.

Show threadWill DormannDec 9, 2024

The man page for tune2fs is pretty clear about this capability.

The person who writes the data to the USB mass storage device can specify that both:
1) The OS that reads the device should panic if the filesystem has an error.
2) The filesystem has an error.

🤦‍♂️

Show thread4censord 
@wdormann dies that mean unless the device is removed (or fixed by fsck on boot), the system will be stuck on a reboot -> kernel panic loop, or does it only work like that on first plugin?
Dec 10, 2024 at 8:16amWeb
Show threadWill DormannDec 10, 2024
@4censord
ChromeOS only auto-mounts filesystems after login. So at least by default, it will not boot loop. It will merely reboot to the log-in screen.