udf: Check length of extended attributes and allocation descriptors

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>

diff --git a/fs/udf/inode.c b/fs/udf/inode.c
index aa023283cc8a2967e006fc6d9dbeb17c3a578b39..789814f274388ab1df3dc3259647a400dbbf543d 100644 (file)
--- a/fs/udf/inode.c
+++ b/fs/udf/inode.c
@@ -1495,6 +1495,16 @@ static void udf_fill_inode(struct inode *inode, struct buffer_head *bh)
                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;