From 19937d0482cfe194fe52e97e59aa58ec911de0d1 Mon Sep 17 00:00:00 2001 From: Simon Arlott Date: Mon, 3 May 2010 10:20:27 +0000 Subject: [PATCH] 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 Signed-off-by: David S. Miller --- drivers/net/ppp_generic.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 75e8903c3754..8518a2e58e53 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -405,6 +405,7 @@ static ssize_t ppp_read(struct file *file, char __user *buf, DECLARE_WAITQUEUE(wait, current); ssize_t ret; struct sk_buff *skb = NULL; + struct iovec iov; ret = count; @@ -448,7 +449,9 @@ static ssize_t ppp_read(struct file *file, char __user *buf, 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; -- 2.34.1