Exposure of Sensitive Information to an Unauthorized Actor
The btrfs_ioctl_clone function in fs/btrfs/ioctl.c in the btrfs functionality in the Linux kernel 2.6.29 through 2.6.32, and possibly other versions, does not ensure that a cloned file descriptor has been opened for reading, which allows local users to read sensitive information from a write-only file descriptor.
CWE-200 - Information Exposure
An information exposure vulnerability is categorized as an information flow (IF) weakness, which can potentially allow unauthorized access to otherwise classified information in the application, such as confidential personal information (demographics, financials, health records, etc.), business secrets, and the application's internal environment.