CVE-2023-52927

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

netfilter: allow exp not to be removed in nf_ct_find_expectation

Currently nf_conntrack_in() calling nf_ct_find_expectation() will remove the exp from the hash table. However, in some scenario, we expect the exp not to be removed when the created ct will not be confirmed, like in OVS and TC conntrack in the following patches.

This patch allows exp not to be removed by setting IPS_CONFIRMED in the status of the tmpl.

The bug actual only if conntrack being used together with netfilter (where conntrack could be used to view and manage the in-kernel connection tracking state table from userspace). The bug doesn't lead to kernel panic, but instead can break netfilter functionality being used.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, prevent module nf_conntrack from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.