skbuff: skb_mac_header_was_set is always true on >32 bit

Looking at the crash in log_martians(), one suspect is that the check for
mac header being set is not correct.  The value of mac_header defaults to
0 on allocation, therefore skb_mac_header_was_set will always be true on
platforms using NET_SKBUFF_USES_OFFSET.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 4 insertions, 0 deletions

diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 1a94a3037370..436695d8deb8 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -201,6 +201,10 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask,
         skb->data = data;
         skb_reset_tail_pointer(skb);
         skb->end = skb->tail + size;
+#ifdef NET_SKBUFF_DATA_USES_OFFSET
+        skb->mac_header = ~0U;
+#endif
+
         /* make sure we initialize shinfo sequentially */
         shinfo = skb_shinfo(skb);
         atomic_set(&shinfo->dataref, 1);