TTY: pty, stop passing NULL to free_tty_struct

In case alloc_tty_struct fails in pty_common_install, we pass NULL to
free_tty_struct. This is invalid as the function is not ready to cope
with that. And even if it was, it is not nice to do that anyway.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 4 insertions, 1 deletions

diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c
index 4399f1dbd131..d9ea9e2c9ec5 100644
--- a/drivers/tty/pty.c
+++ b/drivers/tty/pty.c
@@ -303,9 +303,11 @@ static int pty_common_install(struct tty_driver *driver, struct tty_struct *tty,
         int retval = -ENOMEM;
 
         o_tty = alloc_tty_struct();
+        if (!o_tty)
+                goto err;
         ports[0] = kmalloc(sizeof **ports, GFP_KERNEL);
         ports[1] = kmalloc(sizeof **ports, GFP_KERNEL);
-        if (!o_tty || !ports[0] || !ports[1])
+        if (!ports[0] || !ports[1])
                 goto err_free_tty;
         if (!try_module_get(driver->other->owner)) {
                 /* This cannot in fact currently happen */
@@ -360,6 +362,7 @@ err_free_tty:
         kfree(ports[0]);
         kfree(ports[1]);
         free_tty_struct(o_tty);
+err:
         return retval;
 }