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| author | Michael Hendricks <michael@ndrix.org> | 2019-10-02 09:30:51 -0600 |
|---|---|---|
| committer | Brad Fitzpatrick <bradfitz@golang.org> | 2019-10-02 20:54:54 +0000 |
| commit | f0e940ebc985661f54d31c8d9ba31a553b87041b (patch) | |
| tree | 03b9f5d676aad4ac1ac524664a9be0b1aade56ce /src/net/dnsclient_unix.go | |
| parent | e85ffec784b867f016805873eec5dc91eec1c99a (diff) | |
| download | go-f0e940ebc985661f54d31c8d9ba31a553b87041b.tar.gz go-f0e940ebc985661f54d31c8d9ba31a553b87041b.zip | |
net: avoid an infinite loop in LookupAddr
If a request for a PTR record returned a response with a non-PTR
answer, goLookupPTR would loop forever. Skipping non-PTR answers
guarantees progress through the DNS response.
Fixes #34660
Change-Id: I56f9d21e5342d07e7d843d253267e93a29707904
Reviewed-on: https://go-review.googlesource.com/c/go/+/198460
Run-TryBot: Brad Fitzpatrick <bradfitz@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Diffstat (limited to 'src/net/dnsclient_unix.go')
| -rw-r--r-- | src/net/dnsclient_unix.go | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/src/net/dnsclient_unix.go b/src/net/dnsclient_unix.go index e0a7ef85521..c90892b8330 100644 --- a/src/net/dnsclient_unix.go +++ b/src/net/dnsclient_unix.go @@ -765,6 +765,14 @@ func (r *Resolver) goLookupPTR(ctx context.Context, addr string) ([]string, erro } } if h.Type != dnsmessage.TypePTR { + err := p.SkipAnswer() + if err != nil { + return nil, &DNSError{ + Err: "cannot marshal DNS message", + Name: addr, + Server: server, + } + } continue } ptr, err := p.PTRResource() |