14.5/errata.adoc: routing table memory leak issue

[vladlen]

Test Plan

Description:
This change adds an Open Issues entry to errata.adoc for FreeBSD 14.5-RELEASE regarding a memory leak in the radix4_lockless and radix6_lockless routing algorithms.

The leak occurred during routing table changes (e.g., route additions/deletions), causing kernel memory usage to grow over time. This could affect systems with dynamic routing, such as BGP routers.

Impact:
Systems using the lockless routing algorithms with frequently changing routing tables may experience kernel memory exhaustion over time.

Workaround:
Switch to the non-lockless algorithm: sysctl net.route.algo.inet4.algo=radix4 or sysctl net.route.algo.inet6.algo=radix6.

Status:
Fixed in main and stable/15, and also MFC'd to stable/14 on 3 September 2026. However, the fix did not make it into the releng/14.5 branch, so it is not included in the 14.5-RELEASE image. It will be available in a future patch-level update.

Please review and confirm the wording is appropriate for the errata.adoc.

[ziaee]

website/content/en/releases/14.5R/errata.adoc

66–69

Simplify, show what the user might experience, not stuff under the hood they wont understand. Especially don't lead with that, because their eyes might gloss over.

[pouria]

website/content/en/releases/14.5R/errata.adoc

66–69

It only happens under radix[4|6]_lockless algorithm, it might make sense to let the user know where it happens. But you know better. Just saying.

[ziaee]

website/content/en/releases/14.5R/errata.adoc

66–68

@pouria what about this?

I absolutely do not know better, I only know accessibility and target audience. If we get accessibility right it should be obvious to all of us.

[pouria]

website/content/en/releases/14.5R/errata.adoc

66–68

@pouria what about this?

routing algorithms will not frequently change, but systems whose routing tables change frequently (by default) will dynamically switch to radix_lockless algorithms and these algorithms have this problem.
Despite having multiple BGP routers, I don't have this issue because I use other algorithms that are not loaded by default.

So, I want to make it clear to those who need to hear this announcement that this issue will not affect them if they explicitly defined or changed their routing algo.
what about:

Systems with frequently changing routing tables that use the default radix4_lockless or radix6_lockless algorithms, such as BGP routers, may experience system instability due to a memory leak. This does not affect systems where alternative routing algorithms (e.g. dpdk_lpm, dxr) have been explicitly configured.

[ziaee]

website/content/en/releases/14.5R/errata.adoc

66–68

Thanks for the additional info? Maybe it's enough to just call them the default? Move the type of systems that this is affected up?

Systems with frequently changing routing tables, such as BGP routers, that use the default algorithms may experience system instability due to a memory leak. This does not affect systems where alternative routing algorithms have been explicitly configured.

[pouria]

website/content/en/releases/14.5R/errata.adoc

66–68

LGTM. Thanks!

[vladlen]

@ziaee @pouria The text has been updated according to the discussion.

[ziaee]

LGTM, thanks