Red Hat Security Advisory 2013-1783-01 - The kernel packages contain the Linux kernel, the core of any Linux operating system. A race condition was found in the way asynchronous I/O and fallocate() interacted when using the ext4 file system. A local, unprivileged user could use this flaw to expose random data from an extent whose data blocks have not yet been written, and thus contain data from a deleted file. An information leak flaw was found in the way the Linux kernel's device mapper subsystem, under certain conditions, interpreted data written to snapshot block devices. An attacker could use this flaw to read data from disk blocks in free space, which are normally inaccessible.
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