[PATCH 4.4 39/45] catc: Use heap buffer for memory size test

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Ben Hutchings <b...@decadent.org.uk>

commit 2d6a0e9de03ee658a9adc3bfb2f0ca55dff1e478 upstream.

Allocating USB buffers on the stack is not portable, and no longer
works on x86_64 (with VMAP_STACK enabled as per default).

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
Signed-off-by: David S. Miller <da...@davemloft.net>
Cc: Brad Spengler <spen...@grsecurity.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>

---
 drivers/net/usb/catc.c |   25 ++++++++++++++++++-------
 1 file changed, 18 insertions(+), 7 deletions(-)

--- a/drivers/net/usb/catc.c
+++ b/drivers/net/usb/catc.c
@@ -777,7 +777,7 @@ static int catc_probe(struct usb_interfa
        struct net_device *netdev;
        struct catc *catc;
        u8 broadcast[ETH_ALEN];
-       int i, pktsz, ret;
+       int pktsz, ret;
 
        if (usb_set_interface(usbdev,
                        intf->altsetting->desc.bInterfaceNumber, 1)) {
@@ -841,15 +841,24 @@ static int catc_probe(struct usb_interfa
                 catc->irq_buf, 2, catc_irq_done, catc, 1);
 
        if (!catc->is_f5u011) {
+               u32 *buf;
+               int i;
+
                dev_dbg(dev, "Checking memory size\n");
 
-               i = 0x12345678;
-               catc_write_mem(catc, 0x7a80, &i, 4);
-               i = 0x87654321; 
-               catc_write_mem(catc, 0xfa80, &i, 4);
-               catc_read_mem(catc, 0x7a80, &i, 4);
+               buf = kmalloc(4, GFP_KERNEL);
+               if (!buf) {
+                       ret = -ENOMEM;
+                       goto fail_free;
+               }
+
+               *buf = 0x12345678;
+               catc_write_mem(catc, 0x7a80, buf, 4);
+               *buf = 0x87654321;
+               catc_write_mem(catc, 0xfa80, buf, 4);
+               catc_read_mem(catc, 0x7a80, buf, 4);
          
-               switch (i) {
+               switch (*buf) {
                case 0x12345678:
                        catc_set_reg(catc, TxBufCount, 8);
                        catc_set_reg(catc, RxBufCount, 32);
@@ -864,6 +873,8 @@ static int catc_probe(struct usb_interfa
                        dev_dbg(dev, "32k Memory\n");
                        break;
                }
+
+               kfree(buf);
          
                dev_dbg(dev, "Getting MAC from SEEROM.\n");