diff options
Diffstat (limited to 'fs/notify/fanotify/fanotify.c')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index 6702a6a0bbb5..d51e1bb781cf 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -139,23 +139,32 @@ static bool fanotify_should_send_event(struct fsnotify_mark *inode_mark, return false; } -struct fanotify_event_info *fanotify_alloc_event(struct inode *inode, u32 mask, +struct fanotify_event_info *fanotify_alloc_event(struct fsnotify_group *group, + struct inode *inode, u32 mask, const struct path *path) { struct fanotify_event_info *event; + gfp_t gfp = GFP_KERNEL; + + /* + * For queues with unlimited length lost events are not expected and + * can possibly have security implications. Avoid losing events when + * memory is short. + */ + if (group->max_events == UINT_MAX) + gfp |= __GFP_NOFAIL; if (fanotify_is_perm_event(mask)) { struct fanotify_perm_event_info *pevent; - pevent = kmem_cache_alloc(fanotify_perm_event_cachep, - GFP_KERNEL); + pevent = kmem_cache_alloc(fanotify_perm_event_cachep, gfp); if (!pevent) return NULL; event = &pevent->fae; pevent->response = 0; goto init; } - event = kmem_cache_alloc(fanotify_event_cachep, GFP_KERNEL); + event = kmem_cache_alloc(fanotify_event_cachep, gfp); if (!event) return NULL; init: __maybe_unused @@ -210,10 +219,17 @@ static int fanotify_handle_event(struct fsnotify_group *group, return 0; } - event = fanotify_alloc_event(inode, mask, data); + event = fanotify_alloc_event(group, inode, mask, data); ret = -ENOMEM; - if (unlikely(!event)) + if (unlikely(!event)) { + /* + * We don't queue overflow events for permission events as + * there the access is denied and so no event is in fact lost. + */ + if (!fanotify_is_perm_event(mask)) + fsnotify_queue_overflow(group); goto finish; + } fsn_event = &event->fse; ret = fsnotify_add_event(group, fsn_event, fanotify_merge); |