The second release candidate of Linux Kernel 5.12 is out early because of a nasty swap file bug. And do not use Linux Kernel 5.12 RC1 for testing, you may lose data.
In the Kernel mailing list, Linus Torvalds announced the early release of Linux Kernel 5.12 rc2. The reason for early release because of a critical swap file bug that exists in Linux Kernel 5.12 rc1 which may cause direct damage to your file system data by overwriting them.
If your Linux distribution uses swap files (not swap partition) and if you are running the Linux Kernel 5.12 rc1 then you are probably impacted.
In general, your operating system requires a swap file when there is not much RAM available to perform operation and it dump chunks of data from RAM directly to your disk, freeing up some memory. And when required it copies them back to RAM.
Now, the swap file is rarely used today because most of the hardware loaded with sufficient memory eliminating the use of swap files in your operating system. The swap file bug loses the offset of the start of the swap file. And the worst thing is the swap operation completes. This may result in writing the data in a random section of your disk, corrupting your root partition.
Linux Kernel 5.12 RC2
This is now fixed in the Linux Kernel 5.12 RC2 release.
So, if you are already downloaded and testing RC1, don’t use that. Instead grab the latest Linux Kernel 5.12 RC2 from the git and compile it for your testing.
That said, lots of new hardware support are expected to land in Linux Kernel 5.12. On the processor space, Intel eASIC N5X Device support added whereas Lenovo Laptop Platform Profile support also included. Dynamic Thermal Power Management (DTPM) and Microsoft Surface device optimization also two important addition in this Kernel.
On the storage space usual improvements on XFS, Btrfs is included.
New graphics card support such as Intel Rocket Lake, Tigerlake, and others is coming along well in this Kernel.
You can check out our prior coverage of the new changes here. Linux Kernel 5.12 is expected to be released by end of March 2021, but the timeline may get delayed depending on various factors and bugs.