[PATCH net 1/4] pegasus: Use heap buffers for all register access

[Ben Hutchings]

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")
References: https://bugs.debian.org/852556
Reported-by: Lisandro Damián Nicanor Pérez Meyer <lisan...@debian.org>
Tested-by: Lisandro Damián Nicanor Pérez Meyer <lisan...@debian.org>
Signed-off-by: Ben Hutchings <b...@decadent.org.uk>
---
 drivers/net/usb/pegasus.c | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
index 24e803fe9a53..36674484c6fb 100644
--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -126,40 +126,61 @@ static void async_ctrl_callback(struct urb *urb)
 
 static int get_registers(pegasus_t *pegasus, __u16 indx, __u16 size, void 
*data)
 {
+       u8 *buf;
        int ret;
 
+       buf = kmalloc(size, GFP_NOIO);
+       if (!buf)
+               return -ENOMEM;
+
        ret = usb_control_msg(pegasus->usb, usb_rcvctrlpipe(pegasus->usb, 0),
                              PEGASUS_REQ_GET_REGS, PEGASUS_REQT_READ, 0,
-                             indx, data, size, 1000);
+                             indx, buf, size, 1000);
        if (ret < 0)
                netif_dbg(pegasus, drv, pegasus->net,
                          "%s returned %d\n", __func__, ret);
+       else if (ret <= size)
+               memcpy(data, buf, ret);
+       kfree(buf);
        return ret;
 }
 
-static int set_registers(pegasus_t *pegasus, __u16 indx, __u16 size, void 
*data)
+static int set_registers(pegasus_t *pegasus, __u16 indx, __u16 size,
+                        const void *data)
 {
+       u8 *buf;
        int ret;
 
+       buf = kmemdup(data, size, GFP_NOIO);
+       if (!buf)
+               return -ENOMEM;
+
        ret = usb_control_msg(pegasus->usb, usb_sndctrlpipe(pegasus->usb, 0),
                              PEGASUS_REQ_SET_REGS, PEGASUS_REQT_WRITE, 0,
-                             indx, data, size, 100);
+                             indx, buf, size, 100);
        if (ret < 0)
                netif_dbg(pegasus, drv, pegasus->net,
                          "%s returned %d\n", __func__, ret);
+       kfree(buf);
        return ret;
 }
 
 static int set_register(pegasus_t *pegasus, __u16 indx, __u8 data)
 {
+       u8 *buf;
        int ret;
 
+       buf = kmemdup(&data, 1, GFP_NOIO);
+       if (!buf)
+               return -ENOMEM;
+
        ret = usb_control_msg(pegasus->usb, usb_sndctrlpipe(pegasus->usb, 0),
                              PEGASUS_REQ_SET_REG, PEGASUS_REQT_WRITE, data,
-                             indx, &data, 1, 1000);
+                             indx, buf, 1, 1000);
        if (ret < 0)
                netif_dbg(pegasus, drv, pegasus->net,
                          "%s returned %d\n", __func__, ret);
+       kfree(buf);
        return ret;
 }
 

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