From a22d4c0086f61db0b46d84760fd072d6fc0b58bb Mon Sep 17 00:00:00 2001 From: Johan Hovold Date: Tue, 3 Jan 2017 16:39:49 +0100 Subject: [PATCH] USB: serial: kobil_sct: fix NULL-deref in write commit 21ce57840243c7b70fbc1ebd3dceeb70bb6e9e09 upstream. Fix NULL-pointer dereference in write() should the device lack the expected interrupt-out endpoint: Unable to handle kernel NULL pointer dereference at virtual address 00000054 ... PC is at kobil_write+0x144/0x2a0 [kobil_sct] Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Johan Hovold [bwh: Backported to 3.2: add this check to the existing usb_serial_driver::attach implementation] Signed-off-by: Ben Hutchings --- drivers/usb/serial/kobil_sct.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c index 16a6420828b9..cf5f53083c6b 100644 --- a/drivers/usb/serial/kobil_sct.c +++ b/drivers/usb/serial/kobil_sct.c @@ -150,6 +150,11 @@ static int kobil_startup(struct usb_serial *serial) struct usb_host_interface *altsetting; struct usb_host_endpoint *endpoint; + if (serial->num_interrupt_out < serial->num_ports) { + dev_err(&serial->interface->dev, "missing interrupt-out endpoint\n"); + return -ENODEV; + } + priv = kmalloc(sizeof(struct kobil_private), GFP_KERNEL); if (!priv) return -ENOMEM; -- 2.39.2