55ea440428
Under certain circumstances, the use of `StorageDriver.GetContent` can result in unbounded memory allocations. In particualr, this happens when accessing a layer through the manifests endpoint. This problem is mitigated by setting a 4MB limit when using to access content that may have been accepted from a user. In practice, this means setting the limit with the use of `BlobProvider.Get` by wrapping `StorageDriver.GetContent` in a helper that uses `StorageDriver.Reader` with a `limitReader` that returns an error. When mitigating this security issue, we also noticed that the size of manifests uploaded to the registry is also unlimited. We apply similar logic to the request body of payloads that are full buffered. Signed-off-by: Stephen J Day <stephen.day@docker.com>
71 lines
2.3 KiB
Go
71 lines
2.3 KiB
Go
package handlers
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import (
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"errors"
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"io"
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"net/http"
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ctxu "github.com/docker/distribution/context"
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)
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// closeResources closes all the provided resources after running the target
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// handler.
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func closeResources(handler http.Handler, closers ...io.Closer) http.Handler {
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return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
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for _, closer := range closers {
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defer closer.Close()
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}
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handler.ServeHTTP(w, r)
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})
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}
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// copyFullPayload copies the payload of an HTTP request to destWriter. If it
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// receives less content than expected, and the client disconnected during the
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// upload, it avoids sending a 400 error to keep the logs cleaner.
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//
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// The copy will be limited to `limit` bytes, if limit is greater than zero.
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func copyFullPayload(responseWriter http.ResponseWriter, r *http.Request, destWriter io.Writer, limit int64, context ctxu.Context, action string) error {
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// Get a channel that tells us if the client disconnects
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var clientClosed <-chan bool
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if notifier, ok := responseWriter.(http.CloseNotifier); ok {
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clientClosed = notifier.CloseNotify()
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} else {
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ctxu.GetLogger(context).Warnf("the ResponseWriter does not implement CloseNotifier (type: %T)", responseWriter)
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}
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var body = r.Body
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if limit > 0 {
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body = http.MaxBytesReader(responseWriter, body, limit)
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}
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// Read in the data, if any.
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copied, err := io.Copy(destWriter, body)
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if clientClosed != nil && (err != nil || (r.ContentLength > 0 && copied < r.ContentLength)) {
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// Didn't receive as much content as expected. Did the client
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// disconnect during the request? If so, avoid returning a 400
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// error to keep the logs cleaner.
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select {
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case <-clientClosed:
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// Set the response code to "499 Client Closed Request"
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// Even though the connection has already been closed,
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// this causes the logger to pick up a 499 error
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// instead of showing 0 for the HTTP status.
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responseWriter.WriteHeader(499)
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ctxu.GetLoggerWithFields(context, map[interface{}]interface{}{
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"error": err,
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"copied": copied,
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"contentLength": r.ContentLength,
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}, "error", "copied", "contentLength").Error("client disconnected during " + action)
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return errors.New("client disconnected")
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default:
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}
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}
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if err != nil {
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ctxu.GetLogger(context).Errorf("unknown error reading request payload: %v", err)
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return err
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}
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return nil
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}
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