udldrmfb: udl_get_edid: usb_control_msg buffer must not be on the stack

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>
Cc: stable@vger.kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/udl/udl_connector.c b/drivers/gpu/drm/udl/udl_connector.c
index 3e6208f773e28f434539dbfd4c3de0cb929c9e58..353bc1ea6f68540e5e14d538b2c6f76d6625d437 100644 (file)
--- 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_device *udl)
                block[i] = rbuf[1];
        }
 
+       kfree(rbuf);
        return block;
 
 error:
        kfree(block);
+       kfree(rbuf);
        return NULL;
 }