From 35723111b329490ef3d494a3e676d4244264b236 Mon Sep 17 00:00:00 2001 From: Sebastiaan van Stijn Date: Wed, 12 Jul 2023 14:15:38 +0200 Subject: [PATCH] client: define a "dummy" hostname to use for local connections For local communications (npipe://, unix://), the hostname is not used, but we need valid and meaningful hostname. The current code used the client's `addr` as hostname in some cases, which could contain the path for the unix-socket (`/var/run/docker.sock`), which gets rejected by go1.20.6 and go1.19.11 because of a security fix for [CVE-2023-29406 ][1], which was implemented in https://go.dev/issue/60374. Prior versions go Go would clean the host header, and strip slashes in the process, but go1.20.6 and go1.19.11 no longer do, and reject the host header. This patch introduces a `DummyHost` const, and uses this dummy host for cases where we don't need an actual hostname. Before this patch (using go1.20.6): make GO_VERSION=1.20.6 TEST_FILTER=TestAttach test-integration === RUN TestAttachWithTTY attach_test.go:46: assertion failed: error is not nil: http: invalid Host header --- FAIL: TestAttachWithTTY (0.11s) === RUN TestAttachWithoutTTy attach_test.go:46: assertion failed: error is not nil: http: invalid Host header --- FAIL: TestAttachWithoutTTy (0.02s) FAIL With this patch applied: make GO_VERSION=1.20.6 TEST_FILTER=TestAttach test-integration INFO: Testing against a local daemon === RUN TestAttachWithTTY --- PASS: TestAttachWithTTY (0.12s) === RUN TestAttachWithoutTTy --- PASS: TestAttachWithoutTTy (0.02s) PASS [1]: https://github.com/advisories/GHSA-f8f7-69v5-w4vx Signed-off-by: Sebastiaan van Stijn --- .../github.com/docker/docker/client/client.go | 30 +++++++++++++++++++ .../github.com/docker/docker/client/hijack.go | 6 +++- .../docker/docker/client/request.go | 10 +++---- components/engine/client/client.go | 30 +++++++++++++++++++ components/engine/client/hijack.go | 6 +++- components/engine/client/request.go | 10 +++---- components/engine/pkg/plugins/client.go | 14 +++++++-- 7 files changed, 90 insertions(+), 16 deletions(-) diff --git a/components/cli/vendor/github.com/docker/docker/client/client.go b/components/cli/vendor/github.com/docker/docker/client/client.go index 5031502ac..d483f670e 100644 --- a/components/cli/vendor/github.com/docker/docker/client/client.go +++ b/components/cli/vendor/github.com/docker/docker/client/client.go @@ -60,6 +60,36 @@ import ( "github.com/pkg/errors" ) +// DummyHost is a hostname used for local communication. +// +// It acts as a valid formatted hostname for local connections (such as "unix://" +// or "npipe://") which do not require a hostname. It should never be resolved, +// but uses the special-purpose ".localhost" TLD (as defined in [RFC 2606, Section 2] +// and [RFC 6761, Section 6.3]). +// +// [RFC 7230, Section 5.4] defines that an empty header must be used for such +// cases: +// +// If the authority component is missing or undefined for the target URI, +// then a client MUST send a Host header field with an empty field-value. +// +// However, [Go stdlib] enforces the semantics of HTTP(S) over TCP, does not +// allow an empty header to be used, and requires req.URL.Scheme to be either +// "http" or "https". +// +// For further details, refer to: +// +// - https://github.com/docker/engine-api/issues/189 +// - https://github.com/golang/go/issues/13624 +// - https://github.com/golang/go/issues/61076 +// - https://github.com/moby/moby/issues/45935 +// +// [RFC 2606, Section 2]: https://www.rfc-editor.org/rfc/rfc2606.html#section-2 +// [RFC 6761, Section 6.3]: https://www.rfc-editor.org/rfc/rfc6761#section-6.3 +// [RFC 7230, Section 5.4]: https://datatracker.ietf.org/doc/html/rfc7230#section-5.4 +// [Go stdlib]: https://github.com/golang/go/blob/6244b1946bc2101b01955468f1be502dbadd6807/src/net/http/transport.go#L558-L569 +const DummyHost = "api.moby.localhost" + // ErrRedirect is the error returned by checkRedirect when the request is non-GET. var ErrRedirect = errors.New("unexpected redirect in response") diff --git a/components/cli/vendor/github.com/docker/docker/client/hijack.go b/components/cli/vendor/github.com/docker/docker/client/hijack.go index 0ac8248f2..30509fccb 100644 --- a/components/cli/vendor/github.com/docker/docker/client/hijack.go +++ b/components/cli/vendor/github.com/docker/docker/client/hijack.go @@ -51,7 +51,11 @@ func fallbackDial(proto, addr string, tlsConfig *tls.Config) (net.Conn, error) { } func (cli *Client) setupHijackConn(ctx context.Context, req *http.Request, proto string) (net.Conn, error) { - req.Host = cli.addr + req.URL.Host = cli.addr + if cli.proto == "unix" || cli.proto == "npipe" { + // Override host header for non-tcp connections. + req.Host = DummyHost + } req.Header.Set("Connection", "Upgrade") req.Header.Set("Upgrade", proto) diff --git a/components/cli/vendor/github.com/docker/docker/client/request.go b/components/cli/vendor/github.com/docker/docker/client/request.go index a19d62aa5..8015f572c 100644 --- a/components/cli/vendor/github.com/docker/docker/client/request.go +++ b/components/cli/vendor/github.com/docker/docker/client/request.go @@ -98,16 +98,14 @@ func (cli *Client) buildRequest(method, path string, body io.Reader, headers hea return nil, err } req = cli.addHeaders(req, headers) + req.URL.Host = cli.addr + req.URL.Scheme = cli.scheme if cli.proto == "unix" || cli.proto == "npipe" { - // For local communications, it doesn't matter what the host is. We just - // need a valid and meaningful host name. (See #189) - req.Host = "docker" + // Override host header for non-tcp connections. + req.Host = DummyHost } - req.URL.Host = cli.addr - req.URL.Scheme = cli.scheme - if expectedPayload && req.Header.Get("Content-Type") == "" { req.Header.Set("Content-Type", "text/plain") } diff --git a/components/engine/client/client.go b/components/engine/client/client.go index 5031502ac..d483f670e 100644 --- a/components/engine/client/client.go +++ b/components/engine/client/client.go @@ -60,6 +60,36 @@ import ( "github.com/pkg/errors" ) +// DummyHost is a hostname used for local communication. +// +// It acts as a valid formatted hostname for local connections (such as "unix://" +// or "npipe://") which do not require a hostname. It should never be resolved, +// but uses the special-purpose ".localhost" TLD (as defined in [RFC 2606, Section 2] +// and [RFC 6761, Section 6.3]). +// +// [RFC 7230, Section 5.4] defines that an empty header must be used for such +// cases: +// +// If the authority component is missing or undefined for the target URI, +// then a client MUST send a Host header field with an empty field-value. +// +// However, [Go stdlib] enforces the semantics of HTTP(S) over TCP, does not +// allow an empty header to be used, and requires req.URL.Scheme to be either +// "http" or "https". +// +// For further details, refer to: +// +// - https://github.com/docker/engine-api/issues/189 +// - https://github.com/golang/go/issues/13624 +// - https://github.com/golang/go/issues/61076 +// - https://github.com/moby/moby/issues/45935 +// +// [RFC 2606, Section 2]: https://www.rfc-editor.org/rfc/rfc2606.html#section-2 +// [RFC 6761, Section 6.3]: https://www.rfc-editor.org/rfc/rfc6761#section-6.3 +// [RFC 7230, Section 5.4]: https://datatracker.ietf.org/doc/html/rfc7230#section-5.4 +// [Go stdlib]: https://github.com/golang/go/blob/6244b1946bc2101b01955468f1be502dbadd6807/src/net/http/transport.go#L558-L569 +const DummyHost = "api.moby.localhost" + // ErrRedirect is the error returned by checkRedirect when the request is non-GET. var ErrRedirect = errors.New("unexpected redirect in response") diff --git a/components/engine/client/hijack.go b/components/engine/client/hijack.go index 0ac8248f2..30509fccb 100644 --- a/components/engine/client/hijack.go +++ b/components/engine/client/hijack.go @@ -51,7 +51,11 @@ func fallbackDial(proto, addr string, tlsConfig *tls.Config) (net.Conn, error) { } func (cli *Client) setupHijackConn(ctx context.Context, req *http.Request, proto string) (net.Conn, error) { - req.Host = cli.addr + req.URL.Host = cli.addr + if cli.proto == "unix" || cli.proto == "npipe" { + // Override host header for non-tcp connections. + req.Host = DummyHost + } req.Header.Set("Connection", "Upgrade") req.Header.Set("Upgrade", proto) diff --git a/components/engine/client/request.go b/components/engine/client/request.go index 855b84d6a..43ae0fbf8 100644 --- a/components/engine/client/request.go +++ b/components/engine/client/request.go @@ -99,16 +99,14 @@ func (cli *Client) buildRequest(method, path string, body io.Reader, headers hea return nil, err } req = cli.addHeaders(req, headers) + req.URL.Scheme = cli.scheme + req.URL.Host = cli.addr if cli.proto == "unix" || cli.proto == "npipe" { - // For local communications, it doesn't matter what the host is. We just - // need a valid and meaningful host name. (See #189) - req.Host = "docker" + // Override host header for non-tcp connections. + req.Host = DummyHost } - req.URL.Host = cli.addr - req.URL.Scheme = cli.scheme - if expectedPayload && req.Header.Get("Content-Type") == "" { req.Header.Set("Content-Type", "text/plain") } diff --git a/components/engine/pkg/plugins/client.go b/components/engine/pkg/plugins/client.go index 035330535..5ea2ad75d 100644 --- a/components/engine/pkg/plugins/client.go +++ b/components/engine/pkg/plugins/client.go @@ -19,6 +19,12 @@ import ( const ( defaultTimeOut = 30 + + // dummyHost is a hostname used for local communication. + // + // For local communications (npipe://, unix://), the hostname is not used, + // but we need valid and meaningful hostname. + dummyHost = "plugin.moby.localhost" ) func newTransport(addr string, tlsConfig *tlsconfig.Options) (transport.Transport, error) { @@ -45,8 +51,12 @@ func newTransport(addr string, tlsConfig *tlsconfig.Options) (transport.Transpor return nil, err } scheme := httpScheme(u) - - return transport.NewHTTPTransport(tr, scheme, socket), nil + hostName := u.Host + if hostName == "" || u.Scheme == "unix" || u.Scheme == "npipe" { + // Override host header for non-tcp connections. + hostName = dummyHost + } + return transport.NewHTTPTransport(tr, scheme, hostName), nil } // NewClient creates a new plugin client (http). -- 2.23.0