CVE-2026-74664

Technical Description

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

net: openvswitch: reallocate update replies for mismatched IDs

ovs_flow_cmd_new() preallocates the optional reply skb before it takes

ovs_mutex and before it knows which existing flow will be updated.

That is normally fine because the skb is sized from the request flow

identifier. That identifier also becomes the inserted flow's identifier.

For updates, however, a request with a UFID may miss the UFID lookup and

then fall back to the flow key lookup. That lookup can legitimately find

an existing key-identified flow. UFIDs are optional and the flow key is

the primary identifier.

For echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's

identifier, not the request identifier used for the preallocation. A short

request UFID can therefore leave too little room for the key identifier.

The fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the

update path.

Once the update target has been

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