[PATCH 3.19 143/175] udf: Check length of extended attributes and allocation descriptors

[Greg Kroah-Hartman]

3.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Kara <jack@xxxxxxx>

commit 23b133bdc452aa441fcb9b82cbf6dd05cfd342d0 upstream.

Check length of extended attributes and allocation descriptors when
loading inodes from disk. Otherwise corrupted filesystems could confuse
the code and make the kernel oops.

Reported-by: Carl Henrik Lunde <chlunde@xxxxxxxxxxx>
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/udf/inode.c |    9 +++++++++
 1 file changed, 9 insertions(+)

--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1487,6 +1487,15 @@ reread:
 	}
 	inode->i_generation = iinfo->i_unique;
 
+	/*
+	 * Sanity check length of allocation descriptors and extended attrs to
+	 * avoid integer overflows
+	 */
+	if (iinfo->i_lenEAttr > bs || iinfo->i_lenAlloc > bs)
+		goto out;
+	/* Now do exact checks */
+	if (udf_file_entry_alloc_offset(inode) + iinfo->i_lenAlloc > bs)
+		goto out;
 	/* Sanity checks for files in ICB so that we don't get confused later */
 	if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {
 		/*


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