‘Subtle and very nasty bug’ meant 5.12 rc1 could trash entire filesystems
Linux overlord Linus Torvalds has rushed out a new release candidate of Linux 5.12 after the first in the new series was found to include a ‘subtle and very nasty bug’ that was so serious he marked rc1 as unsuitable for use. “We had a very innocuous code cleanup and simplification that raised no red flags at all, but had a subtle and very nasty bug in it: swap files stopped working right. And they stopped working in a particularly bad way: the offset of the start of the swap file was lost,” Torvalds wrote in a March 3rd post to the Linux Kernel Mailing List. “Swapping still happened, but it happened to the wrong part of the filesystem, with the obvious catastrophic end results.” So catastrophic that, as Torvalds explained, “you can end up with a filesystem that is essentially overwritten by random swap data.
