[PATCH 3.10 31/54] udf: Check length of extended attributes and allocation descriptors

[Greg Kroah-Hartman]

3.10-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>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
[Jan and Jiri fixed it in 3.12 stable, i ported it to 3.10 stable,
 replaced bs by inode->i_sb->s_blocksize]
Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/udf/inode.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1495,6 +1495,16 @@ static void udf_fill_inode(struct inode
 		iinfo->i_checkpoint = le32_to_cpu(efe->checkpoint);
 	}
 
+	/*
+	 * Sanity check length of allocation descriptors and extended attrs to
+	 * avoid integer overflows
+	 */
+	if (iinfo->i_lenEAttr > inode->i_sb->s_blocksize || iinfo->i_lenAlloc > inode->i_sb->s_blocksize)
+		return;
+	/* Now do exact checks */
+	if (udf_file_entry_alloc_offset(inode) + iinfo->i_lenAlloc > inode->i_sb->s_blocksize)
+		return;
+
 	switch (fe->icbTag.fileType) {
 	case ICBTAG_FILE_TYPE_DIRECTORY:
 		inode->i_op = &udf_dir_inode_operations;


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