dup2: Fix return value with oldfd == newfd and invalid fd
The return value of dup2 when oldfd == newfd and the fd isn't valid is
not getting properly sign extended. We end up with 4294967287 instead
of -EBADF.
I've reproduced this on SLE11 (2.6.27.21), openSUSE Factory
(2.6.29-rc5), and Ubuntu 9.04 (2.6.28).
This patch uses a signed int for the error value so it is properly
extended.
Commit 6c5d0512a091480c9f981162227fdb1c9d70e555 introduced this
regression.
Reported-by: Jiri Dluhos <jdluhos@novell.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fcntl.c b/fs/fcntl.c
index cc8e4de..1ad7031 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -117,11 +117,13 @@
{
if (unlikely(newfd == oldfd)) { /* corner case */
struct files_struct *files = current->files;
+ int retval = oldfd;
+
rcu_read_lock();
if (!fcheck_files(files, oldfd))
- oldfd = -EBADF;
+ retval = -EBADF;
rcu_read_unlock();
- return oldfd;
+ return retval;
}
return sys_dup3(oldfd, newfd, 0);
}
