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authorEric Dumazet <edumazet@google.com>2017-02-05 20:23:22 -0800
committerDavid S. Miller <davem@davemloft.net>2017-02-06 10:52:45 -0500
commitebf6c9cb23d7e56eec8575a88071dec97ad5c6e2 (patch)
tree408df47ccbf5f9ee7d12dcf9f9583b18ff0a2b30
parent7892032cfe67f4bde6fc2ee967e45a8fbaf33756 (diff)
ipv6: tcp: add a missing tcp_v6_restore_cb()
Dmitry reported use-after-free in ip6_datagram_recv_specific_ctl() A similar bug was fixed in commit 8ce48623f0cf ("ipv6: tcp: restore IP6CB for pktoptions skbs"), but I missed another spot. tcp_v6_syn_recv_sock() can indeed set np->pktoptions from ireq->pktopts Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
-rw-r--r--net/ipv6/tcp_ipv6.c24
1 files changed, 13 insertions, 11 deletions
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index cb8929681dc7..eaad72c3d746 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -991,6 +991,16 @@ drop:
return 0; /* don't send reset */
}
+static void tcp_v6_restore_cb(struct sk_buff *skb)
+{
+ /* We need to move header back to the beginning if xfrm6_policy_check()
+ * and tcp_v6_fill_cb() are going to be called again.
+ * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
+ */
+ memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
+ sizeof(struct inet6_skb_parm));
+}
+
static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *skb,
struct request_sock *req,
struct dst_entry *dst,
@@ -1182,8 +1192,10 @@ static struct sock *tcp_v6_syn_recv_sock(const struct sock *sk, struct sk_buff *
sk_gfp_mask(sk, GFP_ATOMIC));
consume_skb(ireq->pktopts);
ireq->pktopts = NULL;
- if (newnp->pktoptions)
+ if (newnp->pktoptions) {
+ tcp_v6_restore_cb(newnp->pktoptions);
skb_set_owner_r(newnp->pktoptions, newsk);
+ }
}
}
@@ -1198,16 +1210,6 @@ out:
return NULL;
}
-static void tcp_v6_restore_cb(struct sk_buff *skb)
-{
- /* We need to move header back to the beginning if xfrm6_policy_check()
- * and tcp_v6_fill_cb() are going to be called again.
- * ip6_datagram_recv_specific_ctl() also expects IP6CB to be there.
- */
- memmove(IP6CB(skb), &TCP_SKB_CB(skb)->header.h6,
- sizeof(struct inet6_skb_parm));
-}
-
/* The socket must have it's spinlock held when we get
* here, unless it is a TCP_LISTEN socket.
*