[PATCH 3.16 157/370] USB: serial: io_edgeport: fix NULL-deref at open

Ben Hutchings
2017-03-10T13:49:39Z

From: Johan Hovold <johan@kernel.org>

commit 0dd408425eb21ddf26a692b3c8044c9e7d1a7948 upstream.

Fix NULL-pointer dereference when initialising URBs at open should a
non-EPIC device lack a bulk-in or interrupt-in endpoint.

Unable to handle kernel NULL pointer dereference at virtual address 00000028
...
PC is at edge_open+0x24c/0x3e8 [io_edgeport]

Note that the EPIC-device probe path has the required sanity checks so
this makes those checks partially redundant.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/usb/serial/io_edgeport.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -2761,6 +2761,11 @@ static int edge_startup(struct usb_seria
EDGE_COMPATIBILITY_MASK1,
EDGE_COMPATIBILITY_MASK2 };

+ if (serial->num_bulk_in < 1 || serial->num_interrupt_in < 1) {
+ dev_err(&serial->interface->dev, "missing endpoints\n");
+ return -ENODEV;
+ }
+
dev = serial->dev;

/* create our private serial structure */