virtualbox natdnshostresolver1 CNAME compression completely wrong, corrupted

gistfile1.md

The public dockerhub registry has two CNAMEs in its DNS record. Here's a healthy dig response from an OSX-10.9.5 host:

sbuss@sbuss-local$ dig registry-1.docker.io

; <<>> DiG 9.8.3-P1 <<>> registry-1.docker.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50936
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;registry-1.docker.io.		IN	A

;; ANSWER SECTION:
registry-1.docker.io.	149	IN	CNAME	elb-registry.us-east-1.aws.dckr.io.
elb-registry.us-east-1.aws.dckr.io. 316	IN CNAME us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	54 IN A	52.20.119.187
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	54 IN A	52.7.116.223
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	54 IN A	52.20.61.0

;; Query time: 945 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Dec 16 16:03:17 2015
;; MSG SIZE  rcvd: 216

Notice that we have two CNAMEs in the answer section.

If I run that same command on virtualbox with --natdnshostresolver1 on, I get one of three failures:

sbuss@counsyl-scratch:~$ dig registry-1.docker.io
;; Got bad packet: bad label type
220 bytes
6b 4e 85 a0 00 01 00 05 00 00 00 01 0a 72 65 67          kN...........reg
69 73 74 72 79 2d 31 06 64 6f 63 6b 65 72 02 69          istry-1.docker.i
6f 00 00 01 00 01 c0 0c 00 05 00 01 00 00 0e 10          o...............
00 48 2a 75 73 2d 65 61 73 74 2d 31 2d 65 6c 62          .H*us-east-1-elb
72 65 67 69 73 2d 31 30 66 75 63 73 76 6a 31 74          regis-10fucsvj1t
63 67 79 2d 31 33 33 38 32 31 38 30 30 09 75 73          cgy-133821800.us
2d 65 61 73 74 2d 31 03 65 6c 62 09 61 6d 61 7a          -east-1.elb.amaz
6f 6e 61 77 73 03 63 6f 6d 00 c0 32 00 05 00 01          onaws.com..2....
00 00 0e 10 00 24 0c 65 6c 62 2d 72 65 67 69 73          .....$.elb-regis
74 72 79 09 75 73 2d 65 61 73 74 2d 31 03 61 77          try.us-east-1.aw
73 04 64 63 6b 72 02 69 6f 00 c0 86 00 01 00 01          s.dckr.io.......
00 00 0e 10 00 04 34 14 77 bb c0 86 00 01 00 01          ......4.w.......
00 00 0e 10 00 04 34 14 3d 00 c0 86 00 01 00 01          ......4.=.......
00 00 0e 10 00 04 34 07 74 df bd 01                      ......4.t...

sbuss@counsyl-scratch:~$ dig registry-1.docker.io
;; Got bad packet: bad compression pointer
220 bytes
95 63 85 a0 00 01 00 05 00 00 00 01 0a 72 65 67          .c...........reg
69 73 74 72 79 2d 31 06 64 6f 63 6b 65 72 02 69          istry-1.docker.i
6f 00 00 01 00 01 c0 0c 00 05 00 01 00 00 0e 10          o...............
00 48 2a 75 73 2d 65 61 73 74 2d 31 2d 65 6c 62          .H*us-east-1-elb
72 65 67 69 73 2d 31 30 66 75 63 73 76 6a 31 74          regis-10fucsvj1t
63 67 79 2d 31 33 33 38 32 31 38 30 30 09 75 73          cgy-133821800.us
2d 65 61 73 74 2d 31 03 65 6c 62 09 61 6d 61 7a          -east-1.elb.amaz
6f 6e 61 77 73 03 63 6f 6d 00 c0 32 00 05 00 01          onaws.com..2....
00 00 0e 10 00 24 0c 65 6c 62 2d 72 65 67 69 73          .....$.elb-regis
74 72 79 09 75 73 2d 65 61 73 74 2d 31 03 61 77          try.us-east-1.aw
73 04 64 63 6b 72 02 69 6f 00 c0 86 00 01 00 01          s.dckr.io.......
00 00 0e 10 00 04 34 14 77 bb c0 86 00 01 00 01          ......4.w.......
00 00 0e 10 00 04 34 14 3d 00 c0 86 00 01 00 01          ......4.=.......
00 00 0e 10 00 04 34 07 74 df ce 79                      ......4.t..y


sbuss@counsyl-scratch:~$ dig registry-1.docker.io
;; Warning: Message parser reports malformed message packet.

; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> registry-1.docker.io
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 50476
;; flags: qr aa rd ra ad; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: Message has 1 extra bytes at end

;; QUESTION SECTION:
;registry-1.docker.io.		IN	A

;; ANSWER SECTION:
registry-1.docker.io.	3600	IN	CNAME	us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	3600 IN	CNAME elb-registry.us-east-1.aws.dckr.io.
elb-registry.us-east-1.aws.dckr.io. 3600 IN A	52.20.61.0
elb-registry.us-east-1.aws.dckr.io. 3600 IN A	52.20.119.187
elb-registry.us-east-1.aws.dckr.io. 3600 IN A	52.7.116.223

;; Query time: 5 msec
;; SERVER: 10.0.2.3#53(10.0.2.3)
;; WHEN: Wed Dec 16 15:52:57 PST 2015
;; MSG SIZE  rcvd: 220

This ANSWER section is wrong -- it says that registry-1.docker.io points to an ELB, which points to elb-registry.us-east-1.aws.dckr.io.

From inside the vbox machine, if I dig against google's public DNS server I see the correct response, so this must be virtualbox's dns custom resolver:

sbuss@counsyl-scratch:~$ dig @8.8.8.8 registry-1.docker.io

; <<>> DiG 9.9.5-3ubuntu0.5-Ubuntu <<>> @8.8.8.8 registry-1.docker.io
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 53422
;; flags: qr rd ra; QUERY: 1, ANSWER: 5, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 512
;; QUESTION SECTION:
;registry-1.docker.io.		IN	A

;; ANSWER SECTION:
registry-1.docker.io.	209	IN	CNAME	elb-registry.us-east-1.aws.dckr.io.
elb-registry.us-east-1.aws.dckr.io. 95 IN CNAME	us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	59 IN A	52.20.61.0
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	59 IN A	52.20.119.187
us-east-1-elbregis-10fucsvj1tcgy-133821800.us-east-1.elb.amazonaws.com.	59 IN A	52.7.116.223

;; Query time: 46 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Wed Dec 16 15:56:53 PST 2015
;; MSG SIZE  rcvd: 227

I've run into this same issue. Were you able to resolve this?