[ 076/171] udldrmfb: udl_get_edid: usb_control_msg buffer must not be on the stack

Greg Kroah-Hartman
2013-01-15T23:42:08Z

From: Hans de Goede <hdegoede@redhat.com>

commit 242187b362555849e8c971dfbbfd55f8bd9fa717 upstream.

The buffer passed to usb_control_msg may end up in scatter-gather list, and
may thus not be on the stack. Having it on the stack usually works on x86, but
not on other archs.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/udl/udl_connector.c | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)

--- a/drivers/gpu/drm/udl/udl_connector.c
+++ b/drivers/gpu/drm/udl/udl_connector.c
@@ -22,13 +22,17 @@
static u8 *udl_get_edid(struct udl_device *udl)
{
u8 *block;
- char rbuf[3];
+ char *rbuf;
int ret, i;

block = kmalloc(EDID_LENGTH, GFP_KERNEL);
if (block == NULL)
return NULL;

+ rbuf = kmalloc(2, GFP_KERNEL);
+ if (rbuf == NULL)
+ goto error;
+
for (i = 0; i < EDID_LENGTH; i++) {
ret = usb_control_msg(udl->ddev->usbdev,
usb_rcvctrlpipe(udl->ddev->usbdev, 0), (0x02),
@@ -42,10 +46,12 @@ static u8 *udl_get_edid(struct udl_devic
block[i] = rbuf[1];
}

+ kfree(rbuf);
return block;

error:
kfree(block);
+ kfree(rbuf);
return NULL;
}