On Fri, Nov 20, 2020 at 05:14:26PM -0600, Eric W. Biederman wrote:
> /*
> * Check whether the specified fd has an open file.
> */
> -#define fcheck(fd) fcheck_files(current->files, fd)
> +#define fcheck(fd) files_lookup_fd_rcu(current->files, fd)
Huh?
fs/file.c:1113: file = fcheck(oldfd);
dup3(), under ->file_lock, no rcu_read_lock() in sight
fs/locks.c:2548: f = fcheck(fd);
fcntl_setlk(), ditto
fs/locks.c:2679: f = fcheck(fd);
fcntl_setlk64(), ditto
fs/notify/dnotify/dnotify.c:330: f = fcheck(fd);
fcntl_dirnotify(); this one _is_ under rcu_read_lock().
IOW, unless I've missed something earlier in the series, this is wrong.
