diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 8bb5e4a66328..8b223c0343ee 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -404,14 +404,9 @@ static int mtd_do_writeoob(struct file *file, struct mtd_info *mtd,
 	if (ops.ooboffs && ops.ooblen > (mtd->oobsize - ops.ooboffs))
 		return -EINVAL;
 
-	ops.oobbuf = kmalloc(length, GFP_KERNEL);
-	if (!ops.oobbuf)
-		return -ENOMEM;
-
-	if (copy_from_user(ops.oobbuf, ptr, length)) {
-		kfree(ops.oobbuf);
-		return -EFAULT;
-	}
+	ops.oobbuf = memdup_user(ptr, length);
+	if (IS_ERR(ops.oobbuf))
+		return PTR_ERR(ops.oobbuf);
 
 	start &= ~((uint64_t)mtd->oobsize - 1);
 	ret = mtd->write_oob(mtd, start, &ops);