Merge tag 'fsnotify_for_v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs

Pull fsnotify updates from Jan Kara:
 "Support for new FAN_OPEN_EXEC event and couple of cleanups around
  fsnotify"

* tag 'fsnotify_for_v4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
  fanotify: Use inode_is_open_for_write
  fanotify: Make sure to check event_len when copying
  fsnotify/fdinfo: include fdinfo.h for inotify_show_fdinfo()
  fanotify: introduce new event mask FAN_OPEN_EXEC_PERM
  fsnotify: refactor fsnotify_parent()/fsnotify() paired calls when event is on path
  fanotify: introduce new event mask FAN_OPEN_EXEC
  fanotify: return only user requested event types in event mask

1 files changed, 9 insertions, 3 deletions

diff --git a/fs/notify/fanotify/fanotify_user.c b/fs/notify/fanotify/fanotify_user.c
index e03be5071362..9c870b0d2b56 100644
--- a/fs/notify/fanotify/fanotify_user.c
+++ b/fs/notify/fanotify/fanotify_user.c
@@ -206,7 +206,7 @@ static int process_access_response(struct fsnotify_group *group,
 
 static ssize_t copy_event_to_user(struct fsnotify_group *group,
 				  struct fsnotify_event *event,
-				  char __user *buf)
+				  char __user *buf, size_t count)
 {
 	struct fanotify_event_metadata fanotify_event_metadata;
 	struct file *f;
@@ -220,6 +220,12 @@ static ssize_t copy_event_to_user(struct fsnotify_group *group,
 
 	fd = fanotify_event_metadata.fd;
 	ret = -EFAULT;
+	/*
+	 * Sanity check copy size in case get_one_event() and
+	 * fill_event_metadata() event_len sizes ever get out of sync.
+	 */
+	if (WARN_ON_ONCE(fanotify_event_metadata.event_len > count))
+		goto out_close_fd;
 	if (copy_to_user(buf, &fanotify_event_metadata,
 			 fanotify_event_metadata.event_len))
 		goto out_close_fd;
@@ -295,7 +301,7 @@ static ssize_t fanotify_read(struct file *file, char __user *buf,
 			continue;
 		}
 
-		ret = copy_event_to_user(group, kevent, buf);
+		ret = copy_event_to_user(group, kevent, buf, count);
 		if (unlikely(ret == -EOPENSTALE)) {
 			/*
 			 * We cannot report events with stale fd so drop it.
@@ -669,7 +675,7 @@ static int fanotify_add_inode_mark(struct fsnotify_group *group,
 	 */
 	if ((flags & FAN_MARK_IGNORED_MASK) &&
 	    !(flags & FAN_MARK_IGNORED_SURV_MODIFY) &&
-	    (atomic_read(&inode->i_writecount) > 0))
+	    inode_is_open_for_write(inode))
 		return 0;
 
 	return fanotify_add_mark(group, &inode->i_fsnotify_marks,