The rbd block device driver in drivers/block/rbd.c in the Linux kernel used incomplete permission checking for access to rbd devices, which could be leveraged by local attackers to map or unmap rbd block devices. References: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=f44d04e696feaf13d192d942c4f14ad2e117065a
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1882595]
This was fixed for Fedora with the 5.8.10 stable kernel updates.
Mitigation: As the rbd module can be loaded by a priviledged user or process, its use can be disabled by preventing the module from loading with the following instructions: # echo "install rbd /bin/true" >> /etc/modprobe.d/disable-rdb.conf The system will need to be restarted if the modules isloaded. In most circumstances, the rbd kernel modules will be unable to be unloaded while in use. If the system requires this module to work correctly, (Such as a CEPH node) this mitigation may not be suitable. If you need further assistance, see KCS article https://access.redhat.com/solutions/41278 or contact Red Hat Global Support Services.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:1578 https://access.redhat.com/errata/RHSA-2021:1578
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:1739 https://access.redhat.com/errata/RHSA-2021:1739
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2020-25284