Hello,
We are finding several of our recursive BIND 9.9.1-P3 servers (on Solaris
10 OS) hung and I want to be able to qualify the symptoms in order to
convince others that P4 (or 9.9.2?) will (or will not) address this.
Let me define what "hung" means in our experience: We find that named is
running but will not respond to queries, "rndc status" will respond with output
but that output shows that named is not processing any queries
(see below), other rndc commands appear to work as well (e.g., "rndc dumpdb").
From what I understand, P4 offers this known bug fix:
* A deliberately constructed combination of records could cause named
to hang while populating the additional section of a response.
[RT #31090] -- CVE-2012-5166: Specially crafted DNS data can cause a lockup
in named
Additional details are mentioned in
https://kb.isc.org/article/AA-00801/74/CVE-2012-5166%3A-Specially-crafted-DNS-data-can-cause-a-lockup-in-named.html:
"A nameserver that has become locked-up due to the problem reported in
this advisory will not respond to queries or control commands."
So, our hang issue qualifies for the "...will not respond to queries";
however, it seems that our issue does *not* qualify for the "... will
not respond to... control commands" piece if the responses from "rndc"
are considered control command.
Thoughts?
Thank you.
$ rndc status
version: 9.9.1-P3
(version.bind/txt/ch disabled)
CPUs found: 2
worker threads: 2
UDP listeners per interface: 2
number of zones: 36
debug level: 0
xfers running: 0
xfers deferred: 0
soa queries in progress: 0
query logging is OFF
recursive clients: 0/3900/4000
tcp clients: 0/100
server is up and running
$ time host www.google.com 127.0.0.1
;; connection timed out; no
servers could be reached
real 0m10.035s
user 0m0.017s
sys
0m0.017s
$ time host localhost 127.0.0.1
;; connection timed out; no
servers could be reached
real 0m10.034s
user 0m0.017s
sys
0m0.017s
$ truss -p 17657
/4:
lwp_park(0xFE9AFD48, 0)
(sleeping...)
/3:
lwp_park(0x00000000, 0) (sleeping...)
/1:
sigtimedwait(0xFFBFFBE8, 0xFFBFFB68, 0x00000000) (sleeping...)
/2:
lwp_park(0x00000000, 0)
(sleeping...)
/5:
ioctl(8, DP_POLL, 0xFE98FF80) (sleeping...)
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