| Message ID | 20170216162246.12783-1-andreyknvl@google.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, 2017-02-16 at 17:22 +0100, Andrey Konovalov wrote: > In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet > is forcibly freed via __kfree_skb in dccp_rcv_state_process if > dccp_v6_conn_request successfully returns. > > goto discard; Thanks a lot Andrey ! Acked-by: Eric Dumazet <edumazet@google.com>
From: Andrey Konovalov <andreyknvl@google.com> Date: Thu, 16 Feb 2017 17:22:46 +0100 > In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet > is forcibly freed via __kfree_skb in dccp_rcv_state_process if > dccp_v6_conn_request successfully returns. > > However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb > is saved to ireq->pktopts and the ref count for skb is incremented in > dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed > in dccp_rcv_state_process. > > Fix by calling consume_skb instead of doing goto discard and therefore > calling __kfree_skb. > > Similar fixes for TCP: > > fb7e2399ec17f1004c0e0ccfd17439f8759ede01 [TCP]: skb is unexpectedly freed. > 0aea76d35c9651d55bbaf746e7914e5f9ae5a25d tcp: SYN packets are now > simply consumed > > Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Applied and queued up for -stable, thanks.
diff --git a/net/dccp/input.c b/net/dccp/input.c index ba347184bda9..8fedc2d49770 100644 --- a/net/dccp/input.c +++ b/net/dccp/input.c @@ -606,7 +606,8 @@ int dccp_rcv_state_process(struct sock *sk, struct sk_buff *skb, if (inet_csk(sk)->icsk_af_ops->conn_request(sk, skb) < 0) return 1; - goto discard; + consume_skb(skb); + return 0; } if (dh->dccph_type == DCCP_PKT_RESET) goto discard;
In the current DCCP implementation an skb for a DCCP_PKT_REQUEST packet is forcibly freed via __kfree_skb in dccp_rcv_state_process if dccp_v6_conn_request successfully returns. However, if IPV6_RECVPKTINFO is set on a socket, the address of the skb is saved to ireq->pktopts and the ref count for skb is incremented in dccp_v6_conn_request, so skb is still in use. Nevertheless, it gets freed in dccp_rcv_state_process. Fix by calling consume_skb instead of doing goto discard and therefore calling __kfree_skb. Similar fixes for TCP: fb7e2399ec17f1004c0e0ccfd17439f8759ede01 [TCP]: skb is unexpectedly freed. 0aea76d35c9651d55bbaf746e7914e5f9ae5a25d tcp: SYN packets are now simply consumed Signed-off-by: Andrey Konovalov <andreyknvl@google.com> --- net/dccp/input.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)