[34-longterm 224/260] bluetooth: Fix missing NULL check

Paul Gortmaker
2011-01-02T07:25:24Z

From: Alan Cox <alan@linux.intel.com>

commit c19483cc5e56ac5e22dd19cf25ba210ab1537773 upstream.

Fortunately this is only exploitable on very unusual hardware.

[Reported a while ago but nothing happened so just fixing it]

Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
drivers/bluetooth/hci_ldisc.c | 7 +++++++
1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 76a1abb..283b127 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -258,9 +258,16 @@ static int hci_uart_tty_open(struct tty_struct *tty)

BT_DBG("tty %p", tty);

+ /* FIXME: This btw is bogus, nothing requires the old ldisc to clear
+ the pointer */
if (hu)
return -EEXIST;

+ /* Error if the tty has no write op instead of leaving an exploitable
+ hole */
+ if (tty->ops->write == NULL)
+ return -EOPNOTSUPP;
+
if (!(hu = kzalloc(sizeof(struct hci_uart), GFP_KERNEL))) {
BT_ERR("Can't allocate control structure");
return -ENFILE;
--
1.7.3.3