1 files changed, 2 insertions, 0 deletions

diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 317a80c4d54c..fa20a8f0463a 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -268,6 +268,8 @@ static inline int mtd_write_oob(struct mtd_info *mtd, loff_t to,
         ops->retlen = ops->oobretlen = 0;
         if (!mtd->_write_oob)
                 return -EOPNOTSUPP;
+        if (!(mtd->flags & MTD_WRITEABLE))
+                return -EROFS;
         return mtd->_write_oob(mtd, to, ops);
 }