1 files changed, 11 insertions, 9 deletions

diff --git a/fs/fcntl.c b/fs/fcntl.c
index ce12a6885115..3deec9887089 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -135,18 +135,12 @@ asmlinkage long sys_dup3(unsigned int oldfd, unsigned int newfd, int flags)
         if ((flags & ~O_CLOEXEC) != 0)
                 return -EINVAL;
 
+        if (unlikely(oldfd == newfd))
+                return -EINVAL;
+
         spin_lock(&files->file_lock);
         if (!(file = fcheck(oldfd)))
                 goto out_unlock;
-        err = newfd;
-        if (unlikely(newfd == oldfd)) {
-                if (flags & O_CLOEXEC) {
-                        fdt = files_fdtable(files);
-                        FD_SET(newfd, fdt->close_on_exec);
-                }
-                goto out_unlock;
-        }
-        err = -EBADF;
         if (newfd >= current->signal->rlim[RLIMIT_NOFILE].rlim_cur)
                 goto out_unlock;
         get_file(file);                 /* We are now finished with oldfd */
@@ -194,6 +188,14 @@ out_fput:
 
 asmlinkage long sys_dup2(unsigned int oldfd, unsigned int newfd)
 {
+        if (unlikely(newfd == oldfd)) { /* corner case */
+                struct files_struct *files = current->files;
+                rcu_read_lock();
+                if (!fcheck_files(files, oldfd))
+                        oldfd = -EBADF;
+                rcu_read_unlock();
+                return oldfd;
+        }
         return sys_dup3(oldfd, newfd, 0);
 }