diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 55ba26186351..cc65330ee684 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -302,6 +302,10 @@ int v9fs_parse_param(struct fs_context *fc, struct fs_parameter *param)
                        p9_debug(P9_DEBUG_ERROR, "msize should be at least 4k\n");
                        return -EINVAL;
                }
+               if (result.uint_32 > INT_MAX) {
+                       p9_debug(P9_DEBUG_ERROR, "msize too big\n");
+                       return -EINVAL;
+               }
                clnt->msize = result.uint_32;
                break;
        case Opt_trans: