CVE-2025-37863

Description

In the Linux kernel, the following vulnerability has been resolved: ovl: dont allow datadir only In theory overlayfs could support upper layer directly referring to a data layer, but theres no current use case for this. Originally, when data-only layers were introduced, this wasnt allowed, only introduced by the "datadir+" feature, but without actually handling this case, resulting in an Oops. Fix by disallowing datadir without lowerdir.