net: fix sk_buff head without data area
Eric Dumazet spotted that we have to check skb->head instead
of skb->data as skb->head points to the beginning of the
data area of the skbuff. Similarly, we have to initialize the
skb->head pointer, not skb->data in __alloc_skb_head.
After this fix, netlink crashes in the release path of the
sk_buff, so let's fix that as well.
This bug was introduced in (0ebd0ac net: add function to
allocate sk_buff head without data area).
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index af9185d..cfd777b 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -195,7 +195,7 @@
* the tail pointer in struct sk_buff!
*/
memset(skb, 0, offsetof(struct sk_buff, tail));
- skb->data = NULL;
+ skb->head = NULL;
skb->truesize = sizeof(struct sk_buff);
atomic_set(&skb->users, 1);
@@ -611,7 +611,7 @@
static void skb_release_all(struct sk_buff *skb)
{
skb_release_head_state(skb);
- if (likely(skb->data))
+ if (likely(skb->head))
skb_release_data(skb);
}
diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 12ac6b4..d0b3dd6 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -747,7 +747,7 @@
atomic_dec(&ring->pending);
sock_put(sk);
- skb->data = NULL;
+ skb->head = NULL;
}
#endif
if (skb->sk != NULL)
