An issue was discovered in xfs_setattr_nonsize in fs/xfs/xfs_iops.c in the Linux kernel. XFS partially wedges when a chgrp fails on account of being out of disk quota. xfs_setattr_nonsize is failing to unlock the ILOCK after the xfs_qm_vop_chown_reserve call fails. This is primarily a local DoS attack vector, but it might result as well in remote DoS if the XFS filesystem is exported for instance via NFS.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1746779]