Gabriel Vlasiu reported that xfs_metadump, part of the xfsprogs suite of tools for the XFS filesystem, did not properly obfuscate data. xfs_metadump properly obfuscates active metadata, but the rest of the space within that fs block comes through in the clear. This could lead to exposure of stale disk data via the produced metadump image.
The expectation of xfs_metadump is to obfuscate all but the shortest names in the metadata, as noted in the manpage:
By default, xfs_metadump obfuscates most file (regular file, directory and symbolic link) names and extended attribute names to allow the dumps to be sent without revealing confidential information. Extended attribute values are zeroed and no data is copied. The only exceptions are file or attribute names that are 4 or less characters in length. Also file names that span extents (this can only occur with the mkfs.xfs(8) options where -n size > -b size) are not obfuscated. Names between 5 and 8 characters in length inclusively are partially obfuscated.
While the xfs_metadump tool can be run by unprivileged users, it requires appropriate permissions to access block devices (such as root) where the sensitive data might be dumped. An unprivileged user, without access to the block device, could not use this flaw to obtain sensitive data they would not otherwise have permission to access.
sudo dnf upgrade --advisory=FEDORA-2015-12435
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