net: TestCVE202133195 fails if /etc/resolv.conf specifies ndots larger than 3

[shawndx]

What version of Go are you using (go version)?

$ go version

go version devel go1.17-c95464f0ea Sun Jun 27 05:06:30 2021 +0000 linux/amd64

Does this issue reproduce with the latest release?

Reproducible with go1.16.5

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE="auto"
GOARCH="amd64"
GOBIN=""
GOEXE=""
GOFLAGS=""
GOHOSTARCH="amd64"
GOHOSTOS="linux"

What did you do?

In /etc/resolv.conf there is "options ndots:5", then ./make.bash failed with the following error.

--- FAIL: TestCVE202133195 (0.00s)
dnsclient_unix_test.go:1925: Resolver.LookupSRV returned unexpected error, got "lookup golang.org: SRV target is invalid", want "lookup golang.org: SRV header name is invalid"
dnsclient_unix_test.go:1929: LookupSRV returned unexpected error, got "lookup golang.org: SRV target is invalid", want "lookup golang.org: SRV header name is invalid"
FAIL
FAIL net 5.458s

What did you expect to see?

What did you see instead?

[gopherbot]

Change https://golang.org/cl/330842 mentions this issue: net: fix failure of TestCVE202133195

[dmitshur]

CC @rolandshoemaker.

[shawndx]

@gopherbot please backport to 1.16

[gopherbot]

Backport issue(s) opened: #46981 (for 1.16).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.

[shawndx]

@gopherbot please consider this for backport to 1.15, it's a test failure