inotify: Fix reporting of cookies for inotify events

My rework of handling of notification events (namely commit 7053aee26a35
"fsnotify: do not share events between notification groups") broke
sending of cookies with inotify events. We didn't propagate the value
passed to fsnotify() properly and passed 4 uninitialized bytes to
userspace instead (so it is also an information leak). Sadly I didn't
notice this during my testing because inotify cookies aren't used very
much and LTP inotify tests ignore them.

Fix the problem by passing the cookie value properly.

Fixes: 7053aee26a3548ebaba046ae2e52396ccf56ac6c
Reported-by: Vegard Nossum <vegard.nossum@oracle.com>
Signed-off-by: Jan Kara <jack@suse.cz>

3 files changed, 4 insertions, 3 deletions

diff --git a/fs/notify/inotify/inotify.h b/fs/notify/inotify/inotify.h
index 485eef3f4407..ed855ef6f077 100644
--- a/fs/notify/inotify/inotify.h
+++ b/fs/notify/inotify/inotify.h
@@ -27,6 +27,6 @@ extern int inotify_handle_event(struct fsnotify_group *group,
                                 struct fsnotify_mark *inode_mark,
                                 struct fsnotify_mark *vfsmount_mark,
                                 u32 mask, void *data, int data_type,
-                                const unsigned char *file_name);
+                                const unsigned char *file_name, u32 cookie);
 
 extern const struct fsnotify_ops inotify_fsnotify_ops;
diff --git a/fs/notify/inotify/inotify_fsnotify.c b/fs/notify/inotify/inotify_fsnotify.c
index d5ee56348bb8..43ab1e1a07a2 100644
--- a/fs/notify/inotify/inotify_fsnotify.c
+++ b/fs/notify/inotify/inotify_fsnotify.c
@@ -67,7 +67,7 @@ int inotify_handle_event(struct fsnotify_group *group,
                          struct fsnotify_mark *inode_mark,
                          struct fsnotify_mark *vfsmount_mark,
                          u32 mask, void *data, int data_type,
-                         const unsigned char *file_name)
+                         const unsigned char *file_name, u32 cookie)
 {
         struct inotify_inode_mark *i_mark;
         struct inotify_event_info *event;
@@ -103,6 +103,7 @@ int inotify_handle_event(struct fsnotify_group *group,
         fsn_event = &event->fse;
         fsnotify_init_event(fsn_event, inode, mask);
         event->wd = i_mark->wd;
+        event->sync_cookie = cookie;
         event->name_len = len;
         if (len)
                 strcpy(event->name, file_name);
diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index 497395c8274b..6528b5a54ca0 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -495,7 +495,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark *fsn_mark,
 
         /* Queue ignore event for the watch */
         inotify_handle_event(group, NULL, fsn_mark, NULL, FS_IN_IGNORED,
-                             NULL, FSNOTIFY_EVENT_NONE, NULL);
+                             NULL, FSNOTIFY_EVENT_NONE, NULL, 0);
 
         i_mark = container_of(fsn_mark, struct inotify_inode_mark, fsn_mark);
         /* remove this mark from the idr */