ppp_generic: handle non-linear skbs when passing them to pppd
Frequently when using PPPoE with an interface MTU greater than 1500,
the skb is likely to be non-linear. If the skb needs to be passed to
pppd then the skb data must be read correctly.
The previous commit fixes an issue with accidentally sending skbs
to pppd based on an invalid read of the protocol type. When that
error occurred pppd was reading invalid skb data too.
Signed-off-by: Simon Arlott <simon@fire.lp0.eu>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c
index 75e8903..8518a2e 100644
--- a/drivers/net/ppp_generic.c
+++ b/drivers/net/ppp_generic.c
@@ -405,6 +405,7 @@
DECLARE_WAITQUEUE(wait, current);
ssize_t ret;
struct sk_buff *skb = NULL;
+ struct iovec iov;
ret = count;
@@ -448,7 +449,9 @@
if (skb->len > count)
goto outf;
ret = -EFAULT;
- if (copy_to_user(buf, skb->data, skb->len))
+ iov.iov_base = buf;
+ iov.iov_len = count;
+ if (skb_copy_datagram_iovec(skb, 0, &iov, skb->len))
goto outf;
ret = skb->len;
