[Lucid CVE-2012-6549] isofs: avoid info leak on export

[Luis Henriques]

From: Mathias Krause <minipli at googlemail.com>

CVE-2012-6549

BugLink: http://bugs.launchpad.net/bugs/1156774

For type 1 the parent_offset member in struct isofs_fid gets copied
uninitialized to userland. Fix this by initializing it to 0.

Signed-off-by: Mathias Krause <minipli at googlemail.com>
Signed-off-by: Jan Kara <jack at suse.cz>
(cherry picked from commit fe685aabf7c8c9f138e5ea900954d295bf229175)

Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 fs/isofs/export.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/isofs/export.c b/fs/isofs/export.c
index e81a305..caec670 100644
--- a/fs/isofs/export.c
+++ b/fs/isofs/export.c
@@ -131,6 +131,7 @@ isofs_export_encode_fh(struct dentry *dentry,
 	len = 3;
 	fh32[0] = ei->i_iget5_block;
  	fh16[2] = (__u16)ei->i_iget5_offset;  /* fh16 [sic] */
+	fh16[3] = 0;  /* avoid leaking uninitialized data */
 	fh32[2] = inode->i_generation;
 	if (connectable && !S_ISDIR(inode->i_mode)) {
 		struct inode *parent;
-- 
1.8.1.2