bluetooth: Fix missing NULL check
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>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index 998833d..17361ba 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -256,9 +256,16 @@
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;