From: Ondřej Surý <ondrej@isc.org>
Date: Mon, 23 Mar 2026 10:08:04 +0000 (+0100)
Subject: [9.20] chg: dev: Skip cache flush ordering on NTA expiry
X-Git-Tag: v9.20.22~14
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=5f97f5b0501b2bb78a336f208132f47933366b4d;p=thirdparty%2Fbind9.git

[9.20] chg: dev: Skip cache flush ordering on NTA expiry

dns_view_flushnode() was called in the delete_expired() async
callback, which runs after the query that detected the NTA expiry.
This created a race: the query would proceed with stale cached data
from the NTA period before the flush had a chance to run, resulting
in transient SERVFAIL with EDE 22 (No Reachable Authority).

Skip dns_view_flushnode() in the older branches as the solutions for
older branches are too complicated and this was not a critical bug.

Also simplify the expiry comparison in delete_expired() to a direct
pointer comparison (nta == pval) instead of comparing expiry
timestamps.

Backport of MR !11729

Merge branch 'backport-ondrej/refactor-nta-using-RCU-delete-order-fix-9.20' into 'bind-9.20'

See merge request isc-projects/bind9!11730
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5f97f5b0501b2bb78a336f208132f47933366b4d