X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Ftagged_items.c;h=1ed3b4a914454b6938dd193bb31b2d400dd8eba3;hp=6cd897fa7ae1bf167c7c4f6e21088b670d1a394c;hb=d31b2fee211b1c31420bafe1c2379f6f89bd92fe;hpb=3a900017c59c26af398f9cf375719dbcda378fb8

diff --git a/src/tagged_items.c b/src/tagged_items.c
index 6cd897fa..1ed3b4a9 100644
--- a/src/tagged_items.c
+++ b/src/tagged_items.c
@@ -8,20 +8,18 @@
 /*
  * Copyright (C) 2014 Eric Biggers
  *
- * This file is part of wimlib, a library for working with WIM files.
+ * This file is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the Free
+ * Software Foundation; either version 3 of the License, or (at your option) any
+ * later version.
  *
- * wimlib is free software; you can redistribute it and/or modify it under the
- * terms of the GNU General Public License as published by the Free
- * Software Foundation; either version 3 of the License, or (at your option)
- * any later version.
- *
- * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY
- * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
- * A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * This file is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
  * details.
  *
- * You should have received a copy of the GNU General Public License
- * along with wimlib; if not, see http://www.gnu.org/licenses/.
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this file; if not, see http://www.gnu.org/licenses/.
  */
 
 #ifdef HAVE_CONFIG_H
@@ -45,13 +43,8 @@ struct tagged_item_header {
 	/* Unique identifier for this item.  */
 	le32 tag;
 
-	/* Size of the data of this tagged item, in bytes.  This includes this
-	 * header and should be a multiple of 8.
-	 *
-	 * (Actually, the MS implementation seems to round this up to an 8 byte
-	 * boundary when calculating the offset to the next tagged item, but
-	 * uses this length unmodified when validating the item.  We might as
-	 * well do the same.)  */
+	/* Size of the data of this tagged item, in bytes.  This excludes this
+	 * header and should be a multiple of 8.  */
 	le32 length;
 
 	/* Variable length data  */
@@ -92,16 +85,18 @@ inode_get_tagged_item(const struct wim_inode *inode,
 
 		hdr = (struct tagged_item_header *)p;
 		tag = le32_to_cpu(hdr->tag);
-		len = le32_to_cpu(hdr->length);
+		len = ALIGN(le32_to_cpu(hdr->length), 8);
+
+		/* Length overflow?  */
+		if (unlikely(len > len_remaining - sizeof(struct tagged_item_header)))
+			return NULL;
 
+		/* Matches the item we wanted?  */
 		if (tag == desired_tag && len >= min_data_len)
 			return hdr->data;
 
-		len = (len + 7) & ~7;
-		if (len >= len_remaining)
-			return NULL;
-		len_remaining -= len;
-		p = hdr->data + len;
+		len_remaining -= sizeof(struct tagged_item_header) + len;
+		p += sizeof(struct tagged_item_header) + len;
 	}
 	return NULL;
 }
@@ -118,7 +113,7 @@ inode_add_tagged_item(struct wim_inode *inode, u32 tag, u32 len)
 
 	/* We prepend the item instead of appending it because it's easier.  */
 
-	itemsize = sizeof(struct tagged_item_header) + len;
+	itemsize = sizeof(struct tagged_item_header) + ALIGN(len, 8);
 	newsize = itemsize + inode->i_extra_size;
 
 	buf = MALLOC(newsize);
@@ -135,7 +130,7 @@ inode_add_tagged_item(struct wim_inode *inode, u32 tag, u32 len)
 	hdr = (struct tagged_item_header *)buf;
 	hdr->tag = cpu_to_le32(tag);
 	hdr->length = cpu_to_le32(len);
-	return hdr->data;
+	return memset(hdr->data, 0, ALIGN(len, 8));
 }
 
 static inline struct wimlib_unix_data_disk *