isofs: avoid info leak on export

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@googlemail.com>
Signed-off-by: Jan Kara <jack@suse.cz>

1 files changed, 1 insertions, 0 deletions

diff --git a/fs/isofs/export.c b/fs/isofs/export.c
index aa4356d09eee..1d3804492aa7 100644
--- a/fs/isofs/export.c
+++ b/fs/isofs/export.c
@@ -134,6 +134,7 @@ isofs_export_encode_fh(struct inode *inode,
         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 (parent) {
                 struct iso_inode_info *eparent;