sctp: load transport header after sk_filter
Do not cache pointers into the skb linear segment across sk_filter.
The function call can trigger pskb_expand_head.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/input.c b/net/sctp/input.c
index a701527..47cf460 100644
--- a/net/sctp/input.c
+++ b/net/sctp/input.c
@@ -112,7 +112,6 @@
struct sctp_ep_common *rcvr;
struct sctp_transport *transport = NULL;
struct sctp_chunk *chunk;
- struct sctphdr *sh;
union sctp_addr src;
union sctp_addr dest;
int family;
@@ -127,8 +126,6 @@
if (skb_linearize(skb))
goto discard_it;
- sh = sctp_hdr(skb);
-
/* Pull up the IP and SCTP headers. */
__skb_pull(skb, skb_transport_offset(skb));
if (skb->len < sizeof(struct sctphdr))
@@ -230,7 +227,7 @@
chunk->rcvr = rcvr;
/* Remember the SCTP header. */
- chunk->sctp_hdr = sh;
+ chunk->sctp_hdr = sctp_hdr(skb);
/* Set the source and destination addresses of the incoming chunk. */
sctp_init_addrs(chunk, &src, &dest);
