The driver is using endpoint-sized buffers but must not assume that the
tx and rx buffers are of equal size or a malicious device could overflow
the slab-allocated receive buffer when doing bulk transfers.
Fixes: 985cafccbf9b ("Staging: Comedi: vmk80xx: Add k8061 support")
Cc: stable@xxxxxxxxxxxxxxx # 2.6.31
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
---
drivers/comedi/drivers/vmk80xx.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/drivers/comedi/drivers/vmk80xx.c b/drivers/comedi/drivers/vmk80xx.c
index f2c1572d0cd7..9c56918e3b76 100644
--- a/drivers/comedi/drivers/vmk80xx.c
+++ b/drivers/comedi/drivers/vmk80xx.c
@@ -159,22 +159,20 @@ static void vmk80xx_do_bulk_msg(struct comedi_device *dev)
__u8 rx_addr;
unsigned int tx_pipe;
unsigned int rx_pipe;
- size_t size;
+ size_t tx_size;
+ size_t rx_size;
tx_addr = devpriv->ep_tx->bEndpointAddress;
rx_addr = devpriv->ep_rx->bEndpointAddress;
tx_pipe = usb_sndbulkpipe(usb, tx_addr);
rx_pipe = usb_rcvbulkpipe(usb, rx_addr);
-
- /*
- * The max packet size attributes of the K8061
- * input/output endpoints are identical
- */
- size = usb_endpoint_maxp(devpriv->ep_tx);
+ tx_size = usb_endpoint_maxp(devpriv->ep_tx);
+ rx_size = usb_endpoint_maxp(devpriv->ep_rx);
usb_bulk_msg(usb, tx_pipe, devpriv->usb_tx_buf,
- size, NULL, devpriv->ep_tx->bInterval);
- usb_bulk_msg(usb, rx_pipe, devpriv->usb_rx_buf, size, NULL, HZ * 10);
+ tx_size, NULL, devpriv->ep_tx->bInterval);
+
+ usb_bulk_msg(usb, rx_pipe, devpriv->usb_rx_buf, rx_size, NULL, HZ * 10);
}
static int vmk80xx_read_packet(struct comedi_device *dev)
--
2.32.0
