[PATCH 3.16 082/245] staging: gigaset: fix illegal free on probe errors

[Ben Hutchings]

3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 84f60ca7b326ed8c08582417493982fe2573a9ad upstream.

The driver failed to initialise its receive-buffer pointer, something
which could lead to an illegal free on late probe errors.

Fix this by making sure to clear all driver data at allocation.

Fixes: 2032e2c2309d ("usb_gigaset: code cleanup")
Cc: Tilman Schmidt <tilman@xxxxxxx>
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20191202085610.12719-3-johan@xxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/isdn/gigaset/usb-gigaset.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

--- a/drivers/isdn/gigaset/usb-gigaset.c
+++ b/drivers/isdn/gigaset/usb-gigaset.c
@@ -578,8 +578,7 @@ static int gigaset_initcshw(struct cards
 {
 	struct usb_cardstate *ucs;
 
-	cs->hw.usb = ucs =
-		kmalloc(sizeof(struct usb_cardstate), GFP_KERNEL);
+	cs->hw.usb = ucs = kzalloc(sizeof(struct usb_cardstate), GFP_KERNEL);
 	if (!ucs) {
 		pr_err("out of memory\n");
 		return -ENOMEM;
@@ -591,9 +590,6 @@ static int gigaset_initcshw(struct cards
 	ucs->bchars[3] = 0;
 	ucs->bchars[4] = 0x11;
 	ucs->bchars[5] = 0x13;
-	ucs->bulk_out_buffer = NULL;
-	ucs->bulk_out_urb = NULL;
-	ucs->read_urb = NULL;
 	tasklet_init(&cs->write_tasklet,
 		     gigaset_modem_fill, (unsigned long) cs);