1 files changed, 6 insertions, 8 deletions

diff --git a/fs/notify/inotify/inotify_user.c b/fs/notify/inotify/inotify_user.c
index e0f7c1241a6a..c616a70e8cf9 100644
--- a/fs/notify/inotify/inotify_user.c
+++ b/fs/notify/inotify/inotify_user.c
@@ -359,7 +359,6 @@ static int inotify_find_inode(const char __user *dirname, struct path *path, uns
 }
 
 static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
-			      int *last_wd,
 			      struct inotify_inode_mark *i_mark)
 {
 	int ret;
@@ -367,11 +366,10 @@ static int inotify_add_to_idr(struct idr *idr, spinlock_t *idr_lock,
 	idr_preload(GFP_KERNEL);
 	spin_lock(idr_lock);
 
-	ret = idr_alloc(idr, i_mark, *last_wd + 1, 0, GFP_NOWAIT);
+	ret = idr_alloc_cyclic(idr, i_mark, 1, 0, GFP_NOWAIT);
 	if (ret >= 0) {
 		/* we added the mark to the idr, take a reference */
 		i_mark->wd = ret;
-		*last_wd = i_mark->wd;
 		fsnotify_get_mark(&i_mark->fsn_mark);
 	}
 
@@ -572,7 +570,6 @@ static int inotify_update_existing_watch(struct fsnotify_group *group,
 	int add = (arg & IN_MASK_ADD);
 	int ret;
 
-	/* don't allow invalid bits: we don't want flags set */
 	mask = inotify_arg_to_mask(arg);
 
 	fsn_mark = fsnotify_find_inode_mark(group, inode);
@@ -623,7 +620,6 @@ static int inotify_new_watch(struct fsnotify_group *group,
 	struct idr *idr = &group->inotify_data.idr;
 	spinlock_t *idr_lock = &group->inotify_data.idr_lock;
 
-	/* don't allow invalid bits: we don't want flags set */
 	mask = inotify_arg_to_mask(arg);
 
 	tmp_i_mark = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
@@ -638,8 +634,7 @@ static int inotify_new_watch(struct fsnotify_group *group,
 	if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
 		goto out_err;
 
-	ret = inotify_add_to_idr(idr, idr_lock, &group->inotify_data.last_wd,
-				 tmp_i_mark);
+	ret = inotify_add_to_idr(idr, idr_lock, tmp_i_mark);
 	if (ret)
 		goto out_err;
 
@@ -697,7 +692,6 @@ static struct fsnotify_group *inotify_new_group(unsigned int max_events)
 
 	spin_lock_init(&group->inotify_data.idr_lock);
 	idr_init(&group->inotify_data.idr);
-	group->inotify_data.last_wd = 0;
 	group->inotify_data.user = get_current_user();
 
 	if (atomic_inc_return(&group->inotify_data.user->inotify_devs) >
@@ -751,6 +745,10 @@ SYSCALL_DEFINE3(inotify_add_watch, int, fd, const char __user *, pathname,
 	int ret;
 	unsigned flags = 0;
 
+	/* don't allow invalid bits: we don't want flags set */
+	if (unlikely(!(mask & ALL_INOTIFY_BITS)))
+		return -EINVAL;
+
 	f = fdget(fd);
 	if (unlikely(!f.file))
 		return -EBADF;