CVE-2022-50063

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

net: dsa: felix: suppress non-changes to the tagging protocol

The way in which dsa_tree_change_tag_proto() works is that when

dsa_tree_notify() fails, it doesn't know whether the operation failed

mid way in a multi-switch tree, or it failed for a single-switch tree.

So even though drivers need to fail cleanly in

ds->ops->change_tag_protocol(), DSA will still call dsa_tree_notify()

again, to restore the old tag protocol for potential switches in the

tree where the change did succeeed (before failing for others).

This means for the felix driver that if we report an error in

felix_change_tag_protocol(), we'll get another call where proto_ops ==

old_proto_ops. If we proceed to act upon that, we may do unexpected

things. For example, we will call dsa_tag_8021q_register() twice in a

row, without any dsa_tag_8021q_unregister() in between. Then we will

actually call dsa_tag_8021q_unregister() via old_proto_ops->teardown,

wh

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References