diff --git a/api/client/build.go b/api/client/build.go index 54e76521b7..84f83f7a4f 100644 --- a/api/client/build.go +++ b/api/client/build.go @@ -31,7 +31,6 @@ import ( "github.com/docker/docker/pkg/parsers" "github.com/docker/docker/pkg/progressreader" "github.com/docker/docker/pkg/streamformatter" - "github.com/docker/docker/pkg/symlink" "github.com/docker/docker/pkg/ulimit" "github.com/docker/docker/pkg/units" "github.com/docker/docker/pkg/urlutil" @@ -340,15 +339,15 @@ func getDockerfileRelPath(givenContextDir, givenDockerfile string) (absContextDi absDockerfile = filepath.Join(absContextDir, absDockerfile) } - // Verify that 'filename' is within the build context - absDockerfile, err = symlink.FollowSymlinkInScope(absDockerfile, absContextDir) + // Evaluate symlinks in the path to the Dockerfile too. + absDockerfile, err = filepath.EvalSymlinks(absDockerfile) if err != nil { - return "", "", fmt.Errorf("The Dockerfile (%s) must be within the build context (%s)", givenDockerfile, givenContextDir) + return "", "", fmt.Errorf("unable to evaluate symlinks in Dockerfile path: %v", err) } if _, err := os.Lstat(absDockerfile); err != nil { if os.IsNotExist(err) { - return "", "", fmt.Errorf("Cannot locate Dockerfile: absDockerfile: %q", absDockerfile) + return "", "", fmt.Errorf("Cannot locate Dockerfile: %q", absDockerfile) } return "", "", fmt.Errorf("unable to stat Dockerfile: %v", err) } @@ -357,6 +356,10 @@ func getDockerfileRelPath(givenContextDir, givenDockerfile string) (absContextDi return "", "", fmt.Errorf("unable to get relative Dockerfile path: %v", err) } + if strings.HasPrefix(relDockerfile, ".."+string(filepath.Separator)) { + return "", "", fmt.Errorf("The Dockerfile (%s) must be within the build context (%s)", givenDockerfile, givenContextDir) + } + return absContextDir, relDockerfile, nil }