USB: wusb: don't use the stack to read security descriptor
An urb's transfer buffer must be kmalloc'd memory and not point to the
stack or a DMA API warning results.
Signed-off-by: David Vrabel <david.vrabel@csr.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/wusbcore/security.c b/drivers/usb/wusbcore/security.c
index b2f149f..4516c36 100644
--- a/drivers/usb/wusbcore/security.c
+++ b/drivers/usb/wusbcore/security.c
@@ -200,35 +200,40 @@
{
int result, bytes, secd_size;
struct device *dev = &usb_dev->dev;
- struct usb_security_descriptor secd;
+ struct usb_security_descriptor *secd;
const struct usb_encryption_descriptor *etd, *ccm1_etd = NULL;
- void *secd_buf;
const void *itr, *top;
char buf[64];
+ secd = kmalloc(sizeof(struct usb_security_descriptor), GFP_KERNEL);
+ if (secd == NULL) {
+ result = -ENOMEM;
+ goto out;
+ }
+
result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
- 0, &secd, sizeof(secd));
+ 0, secd, sizeof(struct usb_security_descriptor));
if (result < sizeof(secd)) {
dev_err(dev, "Can't read security descriptor or "
"not enough data: %d\n", result);
- goto error_secd;
+ goto out;
}
- secd_size = le16_to_cpu(secd.wTotalLength);
- secd_buf = kmalloc(secd_size, GFP_KERNEL);
- if (secd_buf == NULL) {
+ secd_size = le16_to_cpu(secd->wTotalLength);
+ secd = krealloc(secd, secd_size, GFP_KERNEL);
+ if (secd == NULL) {
dev_err(dev, "Can't allocate space for security descriptors\n");
- goto error_secd_alloc;
+ goto out;
}
result = usb_get_descriptor(usb_dev, USB_DT_SECURITY,
- 0, secd_buf, secd_size);
+ 0, secd, secd_size);
if (result < secd_size) {
dev_err(dev, "Can't read security descriptor or "
"not enough data: %d\n", result);
- goto error_secd_all;
+ goto out;
}
bytes = 0;
- itr = secd_buf + sizeof(secd);
- top = secd_buf + result;
+ itr = &secd[1];
+ top = (void *)secd + result;
while (itr < top) {
etd = itr;
if (top - itr < sizeof(*etd)) {
@@ -259,24 +264,16 @@
dev_err(dev, "WUSB device doesn't support CCM1 encryption, "
"can't use!\n");
result = -EINVAL;
- goto error_no_ccm1;
+ goto out;
}
wusb_dev->ccm1_etd = *ccm1_etd;
dev_dbg(dev, "supported encryption: %s; using %s (0x%02x/%02x)\n",
buf, wusb_et_name(ccm1_etd->bEncryptionType),
ccm1_etd->bEncryptionValue, ccm1_etd->bAuthKeyIndex);
result = 0;
- kfree(secd_buf);
out:
+ kfree(secd);
return result;
-
-
-error_no_ccm1:
-error_secd_all:
- kfree(secd_buf);
-error_secd_alloc:
-error_secd:
- goto out;
}
void wusb_dev_sec_rm(struct wusb_dev *wusb_dev)