[PATCH 3.16 278/370] pegasus: Use heap buffers for all register access

Ben Hutchings
2017-03-10T13:37:10Z

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

commit 5593523f968bc86d42a035c6df47d5e0979b5ace 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")
References: https://bugs.debian.org/852556
Reported-by: Lisandro Damián Nicanor Pérez Meyer <lisandro@debian.org>
Tested-by: Lisandro Damián Nicanor Pérez Meyer <lisandro@debian.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
drivers/net/usb/pegasus.c | 29 +++++++++++++++++++++++++----
1 file changed, 25 insertions(+), 4 deletions(-)

--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -126,40 +126,61 @@ static void async_ctrl_callback(struct u

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;
}