CVE-2026-98490

/// Technical description

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

net: openvswitch: conntrack: fix helper UAF due to extensions realloc

While calling the helpers, a raw pointer to the extensions area is

wired into expectations list:

-> nf_ct_helper()

-> helper->help()

-> nf_ct_expect_related_report()

-> nf_ct_expect_insert()

-> hlist_add_head_rcu(&exp->lnode, &master_help->expectations)

In case the connection is not confirmed yet, more extensions can be

added afterwards with *_ext_add() calls reallocating the extension

space and leaving the now invalid pointer in the expectations list

that is later accessed while removing the expectation.

Make sure that helpers are called at the end after all the other

extensions are already added.

Note that the helper rejection now leaves the mark and labels set,

but that's not different from how the NAT was handled before or how

the mark and the labels were handled on confirmation failure. And

there are no atomicity guara

/// 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