net: usbnet: fix SG initialisation

[ Upstream commit fdc3452cd2c7b2bfe0f378f92123f4f9a98fa2bd ]

Commit 60e453a940ac ("USBNET: fix handling padding packet")
added an extra SG entry in case padding is necessary, but
failed to update the initialisation of the list. This can
cause list traversal to fall off the end of the list,
resulting in an oops.

Fixes: 60e453a940ac ("USBNET: fix handling padding packet")
Reported-by: Thomas Kear <thomas@kear.co.nz>
Cc: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Bjørn Mork <bjorn@mork.no>
Tested-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/usb/usbnet.c b/drivers/net/usb/usbnet.c
index 8494bb5..aba04f5 100644 (file)
--- a/drivers/net/usb/usbnet.c
+++ b/drivers/net/usb/usbnet.c
@@ -1245,7 +1245,7 @@ static int build_dma_sg(const struct sk_buff *skb, struct urb *urb)
                return -ENOMEM;
 
        urb->num_sgs = num_sgs;
-       sg_init_table(urb->sg, urb->num_sgs);
+       sg_init_table(urb->sg, urb->num_sgs + 1);
 
        sg_set_buf(&urb->sg[s++], skb->data, skb_headlen(skb));
        total_len += skb_headlen(skb);