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

Greg Kroah-Hartman
2015-03-04T06:23:50Z

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>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
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) {
/*