Linux Kernel 5.12 rc-1 Not Ready for Use

In a recent message on the Linux Kernel Mailing List, Linus Torvalds warned everyone not to use the 5.12-rc1 kernel, due to an “unusually nasty bug” that was not caught during normal testing.

“The reason is fairly straightforward,” Torvalds explains, “this merge window, 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 … the offset of the start of the swap file was lost.”  Swapping still happened, he says, “but it happened to the wrong part of the filesystem, with the obvious catastrophic end results.” 

Jim Salter at Ars Technica notes that it’s particularly important that “developers not base their own work around that release and potentially carry a very nasty bug forward further down the line.” The bug has been fixed in the current tree.