Re: [PATCH IPV6 1/1] ipv6: allocate enough headroom in ip6_finish_output2()
From: David Ahern <hidden>
Date: 2021-07-07 14:45:24
Also in:
lkml
On 7/7/21 8:04 AM, Vasily Averin wrote:
quoted hunk ↗ jump to hunk
diff --git a/net/ipv6/ip6_output.c b/net/ipv6/ip6_output.c index ff4f9eb..e5af740 100644 --- a/net/ipv6/ip6_output.c +++ b/net/ipv6/ip6_output.c@@ -61,9 +61,24 @@ static int ip6_finish_output2(struct net *net, struct sock *sk, struct sk_buff * struct dst_entry *dst = skb_dst(skb); struct net_device *dev = dst->dev; const struct in6_addr *nexthop; + unsigned int hh_len = LL_RESERVED_SPACE(dev); struct neighbour *neigh; int ret; + /* Be paranoid, rather than too clever. */ + if (unlikely(skb_headroom(skb) < hh_len && dev->header_ops)) { + struct sk_buff *skb2; + + skb2 = skb_realloc_headroom(skb, LL_RESERVED_SPACE(dev));
why not use hh_len here?
+ if (!skb2) {
+ kfree_skb(skb);
+ return -ENOMEM;
+ }
+ if (skb->sk)
+ skb_set_owner_w(skb2, skb->sk);
+ consume_skb(skb);
+ skb = skb2;
+ }
if (ipv6_addr_is_multicast(&ipv6_hdr(skb)->daddr)) {
struct inet6_dev *idev = ip6_dst_idev(skb_dst(skb));