Published: 03 September 2010

The xfs_swapext function in fs/xfs/xfs_dfrag.c in the Linux kernel before 2.6.35 does not properly check the file descriptors passed to the SWAPEXT ioctl, which allows local users to leverage write access and obtain read access by swapping one file into another file.

From the Ubuntu security team

Dan Rosenberg discovered that the swapexit xfs ioctl did not correctly check file permissions. A local attacker could exploit this to read from write-only files, leading to a loss of privacy.