GrapheneOS ships kernel updates much faster than stock Pixel OS. For devices using 5.10 LTS branch, we’re on latest 5.10.199 revision compared to the stock OS being on 5.10.157. This can be a hassle due to regressions we need to solve, but it recently saved us a lot of trouble.
Android 14 released with a major f2fs data corruption bug caused by LTS kernel backporting shenanigans. This was already resolved in the kernel shipped by GrapheneOS in our experimental Android 14 release on October 6th/7th (we ported in around 2 days after it was published).
In addition to fixing a backport, November release of AOSP and stock Pixel OS include a few robustness improvements to hold up better against future f2fs data corruption bugs or hardware issues causing data corruption. f2fs recently incorporated those improvements upstream too.
Anyone have more information on the data corruption bug itself? I’m curious about the bug, but a quick Google search was not revealing.
the issue was caused by a bug in the F2FS file system, which Pixel phones use for their data partition. While older Pixels also use the same file system, the bug is seemingly found in kernels based on Linux 5.10, used by the Pixel 6 and 7 series.
The bug is triggered by a “corrupted xattr (extended attribute) entry that occurs when a secondary user is removed and the file system is F2FS,” as per Mishaal. Google’s fix for the bug runs a file system consistency check (fsck) when the data partition is mounted. This also explains why affected Pixels take unusually long to boot after installing the November security patch.
Source: https://www.androidpolice.com/what-led-android-14-lock-some-pixel-users-phone/
The official statement from Google can be found here: https://support.google.com/pixelphone/thread/241474288
As for the bug eport itself, that is available on their issue tracker here:
https://issuetracker.google.com/issues/305766503
https://issuetracker.google.com/issues/307592536
