CVE-2022-49110

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

netfilter: conntrack: revisit gc autotuning

as of commit 4608fdfc07e1 ("netfilter: conntrack: collect all entries in one cycle") conntrack gc was changed to run every 2 minutes.

On systems where conntrack hash table is set to large value, most evictions happen from gc worker rather than the packet path due to hash table distribution.

This causes netlink event overflows when events are collected.

This change collects average expiry of scanned entries and reschedules to the average remaining value, within 1 to 60 second interval.

To avoid event overflows, reschedule after each bucket and add a limit for both run time and number of evictions per run.

If more entries have to be evicted, reschedule and restart 1 jiffy into the future.

This vulnerability is rated as a Moderate impact for Red Hat Enterprise Linux because triggering the condition requires an uncommonly large connection-tracking table alongside active netlink monitoring, limiting the blast radius under standard operational settings. In default environments, connection tracking garbage collection operates without overwhelming event queues, and the flaw results in dropped event notifications rather than system compromise or privilege escalation. Systems that do not deploy connection-tracking netlink consumers (such as conntrackd) are not susceptible to event drops from this issue.

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.