notify: unused event private race

inotify decides if private data it passed to get added to an event was
used by checking list_empty().  But it's possible that the event may
have been dequeued and the private event removed so it would look empty.

The fix is to use the return code from fsnotify_add_notify_event rather
than looking at the list.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Eric Paris
2009-08-16 21:51:44 -04:00
committed by Linus Torvalds
parent 0f66f96d21
commit eef3a116be
3 changed files with 13 additions and 14 deletions

View File

@@ -386,6 +386,7 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
struct fsnotify_event *ignored_event;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
int ret;
ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL,
FSNOTIFY_EVENT_NONE, NULL, 0,
@@ -404,10 +405,8 @@ void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
fsn_event_priv->group = group;
event_priv->wd = ientry->wd;
fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
/* did the private data get added? */
if (list_empty(&fsn_event_priv->event_list))
ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
if (ret)
inotify_free_event_priv(fsn_event_priv);
skip_send_ignore: