A vulnerability has been reported in the Linux Kernel, which can be exploited by malicious, local users and malicious, local users in a guest virtual machine to gain escalated privileges.

The vulnerability is caused due to SG_IO SCSI IOCTL commands being passed down to the block device without properly honoring access restrictions to e.g. single partitions or LVM volumes. This can e.g. be exploited by a privileged guest user in certain virtualisation setups to read from or write to the host's block device.

Solution
Restrict access to trusted users only.

Provided and/or discovered by
Paolo Bonzini, Red Hat

Original Advisory
Paolo Bonzini:
https://lkml.org/lkml/2011/12/22/270

Red Hat bug #752375:
https://bugzilla.redhat.com/show_bug.cgi?id=752375

Other references
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