From: Johan Hovold <johan@kernel.org>
Date: Tue, 3 Jan 2017 15:40:00 +0000 (+0100)
Subject: USB: serial: pl2303: fix NULL-deref at open
X-Git-Tag: v3.2.87~121
X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=commitdiff_plain;h=ad5f2860191be1040a38caec5eac879d084adfa4;ds=sidebyside

USB: serial: pl2303: fix NULL-deref at open

commit 76ab439ed1b68778e9059c79ecc5d14de76c89a8 upstream.

Fix NULL-pointer dereference in open() should a type-0 or type-1 device
lack the expected endpoints:

Unable to handle kernel NULL pointer dereference at virtual address 00000030
...
PC is at pl2303_open+0x38/0xec [pl2303]

Note that a missing interrupt-in endpoint would have caused open() to
fail.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---

diff --git a/drivers/usb/serial/pl2303.c b/drivers/usb/serial/pl2303.c
index a440387fd3f7..c23f7161fd34 100644
--- a/drivers/usb/serial/pl2303.c
+++ b/drivers/usb/serial/pl2303.c
@@ -185,10 +185,18 @@ static int pl2303_vendor_write(__u16 value, __u16 index,
 static int pl2303_startup(struct usb_serial *serial)
 {
 	struct pl2303_private *priv;
+	unsigned char num_ports = serial->num_ports;
 	enum pl2303_type type = type_0;
 	unsigned char *buf;
 	int i;
 
+	if (serial->num_bulk_in < num_ports ||
+			serial->num_bulk_out < num_ports ||
+			serial->num_interrupt_in < num_ports) {
+		dev_err(&serial->interface->dev, "missing endpoints\n");
+		return -ENODEV;
+	}
+
 	buf = kmalloc(10, GFP_KERNEL);
 	if (buf == NULL)
 		return -ENOMEM;