A data leak flaw was found in the way XFS_IOC_ALLOCSP IOCTL in the XFS
filesystem allowed for a size increase of files with unaligned size. A
local attacker could use this flaw to leak data on the XFS filesystem
otherwise not accessible to them.

Kirill Tkhai discovered that the XFS file system implementation in the
Linux kernel did not calculate size correctly when pre-allocating space in
some situations. A local attacker could use this to expose sensitive
information.