Squashfs: add corruption check for type in squashfs_readdir()
We read the type field from disk. This value should be sanity
checked for correctness to avoid an out of bounds access when
reading the squashfs_filetype_table array.
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
diff --git a/fs/squashfs/squashfs_fs.h b/fs/squashfs/squashfs_fs.h
index 9e2349d..4b2beda 100644
--- a/fs/squashfs/squashfs_fs.h
+++ b/fs/squashfs/squashfs_fs.h
@@ -87,7 +87,7 @@
#define SQUASHFS_COMP_OPTS(flags) SQUASHFS_BIT(flags, \
SQUASHFS_COMP_OPT)
-/* Max number of types and file types */
+/* Inode types including extended types */
#define SQUASHFS_DIR_TYPE 1
#define SQUASHFS_REG_TYPE 2
#define SQUASHFS_SYMLINK_TYPE 3
@@ -103,6 +103,9 @@
#define SQUASHFS_LFIFO_TYPE 13
#define SQUASHFS_LSOCKET_TYPE 14
+/* Max type value stored in directory entry */
+#define SQUASHFS_MAX_DIR_TYPE 7
+
/* Xattr types */
#define SQUASHFS_XATTR_USER 0
#define SQUASHFS_XATTR_TRUSTED 1