Bug 2347755 (CVE-2022-49110)

Summary: CVE-2022-49110 kernel: netfilter: conntrack: revisit gc autotuning
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-02-26 03:05:36 UTC
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.

Comment 1 Avinash Hanwate 2025-02-26 14:05:08 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022602-CVE-2022-49110-5519@gregkh/T

Comment 4 Avinash Hanwate 2025-02-26 18:02:25 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025022602-CVE-2022-49110-5519@gregkh/T