On Mon, Dec 07, 2020 at 10:46:57PM +0000, Al Viro wrote: > 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. I have missed something, all right. Ignore that comment...
