Due to a problematic patch backported from Linux 6.5 to 6.1, which causes interference between Ext4 code and iomap, there is a risk of data corruption in older kernels — especially in the latest point releases of Linux 6.1 LTS, currently found in distributions such as Debian 12.
A potential filesystem EXT4 data corruption bug found in similar versions of Linux 6.1.64 and 6.1.55 is attributed to a subtle interaction between iomap and Ext4. The new Linux 6.1.66 release has already fixed the identified bug.
Source: linux.org.ru
