From 7b797d5b150775d717cb03b5ada28b8bad99afab Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Sun, 16 Sep 2007 16:21:42 -0700 Subject: [PATCH] [PPP] generic: Call skb_cow_head before scribbling over skb It's rude to write over data that other people are still using. So call skb_cow_head before PPP proceeds to modify the skb data. Signed-off-by: Herbert Xu Signed-off-by: David S. Miller --- drivers/net/ppp_generic.c | 12 ++---------- 1 file changed, 2 insertions(+), 10 deletions(-) diff --git a/drivers/net/ppp_generic.c b/drivers/net/ppp_generic.c index 9293c82ef2af..7e21342becb2 100644 --- a/drivers/net/ppp_generic.c +++ b/drivers/net/ppp_generic.c @@ -899,17 +899,9 @@ ppp_start_xmit(struct sk_buff *skb, struct net_device *dev) /* Put the 2-byte PPP protocol number on the front, making sure there is room for the address and control fields. */ - if (skb_headroom(skb) < PPP_HDRLEN) { - struct sk_buff *ns; + if (skb_cow_head(skb, PPP_HDRLEN)) + goto outf; - ns = alloc_skb(skb->len + dev->hard_header_len, GFP_ATOMIC); - if (ns == 0) - goto outf; - skb_reserve(ns, dev->hard_header_len); - skb_copy_bits(skb, 0, skb_put(ns, skb->len), skb->len); - kfree_skb(skb); - skb = ns; - } pp = skb_push(skb, 2); proto = npindex_to_proto[npi]; pp[0] = proto >> 8;