prevent out-of-memory errors (#5674)

impose a maximum size on body of incoming HTTP requests and responses.

internal/api/api_config_pathdefaults.go

@@ -1,6 +1,7 @@
 package api //nolint:revive
 
 import (
+	"io"
 	"net/http"
 
 	"github.com/bluenviron/mediamtx/internal/conf"
@@ -18,7 +19,7 @@ func (a *API) onConfigPathDefaultsGet(ctx *gin.Context) {
 
 func (a *API) onConfigPathDefaultsPatch(ctx *gin.Context) {
 	var p conf.OptionalPath
-	err := jsonwrapper.Decode(ctx.Request.Body, &p)
+	err := jsonwrapper.Decode(io.LimitReader(ctx.Request.Body, maxInboundConfigSize), &p)
 	if err != nil {
 		a.writeError(ctx, http.StatusBadRequest, err)
 		return