A flaw was found in the implementation of the BTRFS file system code in the Linux kernel. An attacker, who is able to mount a crafted BTRFS filesystem and perform common filesystem operations, can possibly cause an out-of-bounds write to memory. This could lead to memory corruption or privilege escalation.

Mitigation

As the BTRFS module will be auto-loaded when required, its use can be disabled by preventing the module from loading with the following instructions:

echo "install btrfs /bin/true" >> /etc/modprobe.d/disable-btrfs.conf

The system will need to be restarted if the BTRFS modules are loaded, it may be possible to unload them. In most circumstances, the BTRFS kernel modules will be unable to be unloaded while any BTRFS filesystems are mounted or in use.

If the system requires this module to work correctly, this mitigation may not be suitable.

If you need further assistance, see KCS article <https://access.redhat.com/solutions/41278&gt; or contact Red Hat Global Support Services.