From f44a0a3c6329900774a12b44ffa4f2caa86c018e Mon Sep 17 00:00:00 2001
From: Kaho Ng <ngkaho1234@gmail.com>
Date: Thu, 30 Jun 2016 05:30:28 +0800
Subject: [PATCH] ext4: add filetype checking to ext4_mknod

---
 src/ext4.c | 16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/ext4.c b/src/ext4.c
index 0f2f07a..7f10e11 100644
--- a/src/ext4.c
+++ b/src/ext4.c
@@ -2448,9 +2448,23 @@ int ext4_mknod(const char *path, int filetype, uint32_t dev)
 	if (mp->fs.read_only)
 		return EROFS;
 
+	/*
+	 * The filetype shouldn't be normal file, directory or
+	 * unknown.
+	 */
 	if (filetype == EXT4_DE_UNKNOWN ||
 	    filetype == EXT4_DE_REG_FILE ||
-	    filetype == EXT4_DE_DIR)
+	    filetype == EXT4_DE_DIR ||
+	    filetype == EXT4_DE_SYMLINK)
+		return EINVAL;
+
+	/*
+	 * Nor should it be any bogus value.
+	 */
+	if (filetype != EXT4_DE_CHRDEV &&
+	    filetype != EXT4_DE_BLKDEV &&
+	    filetype != EXT4_DE_FIFO &&
+	    filetype != EXT4_DE_SOCK)
 		return EINVAL;
 
 	EXT4_MP_LOCK(mp);