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

Greg Kroah-Hartman
2015-10-18T02:52:11Z

From: Jan Kara <jack@suse.cz>

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@ping.uio.no>
Cc: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
[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@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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;