From 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 Mon Sep 17 00:00:00 2001 From: Mohamed Ghannam Date: Tue, 5 Dec 2017 20:58:35 +0000 Subject: [PATCH] dccp: CVE-2017-8824: use-after-free in DCCP code Whenever the sock object is in DCCP_CLOSED state, dccp_disconnect() must free dccps_hc_tx_ccid and dccps_hc_rx_ccid and set to NULL. Signed-off-by: Mohamed Ghannam Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller --- net/dccp/proto.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/net/dccp/proto.c b/net/dccp/proto.c index b68168fcc06a..9d43c1f40274 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -259,6 +259,7 @@ int dccp_disconnect(struct sock *sk, int flags) { struct inet_connection_sock *icsk = inet_csk(sk); struct inet_sock *inet = inet_sk(sk); + struct dccp_sock *dp = dccp_sk(sk); int err = 0; const int old_state = sk->sk_state; @@ -278,6 +279,10 @@ int dccp_disconnect(struct sock *sk, int flags) sk->sk_err = ECONNRESET; dccp_clear_xmit_timers(sk); + ccid_hc_rx_delete(dp->dccps_hc_rx_ccid, sk); + ccid_hc_tx_delete(dp->dccps_hc_tx_ccid, sk); + dp->dccps_hc_rx_ccid = NULL; + dp->dccps_hc_tx_ccid = NULL; __skb_queue_purge(&sk->sk_receive_queue); __skb_queue_purge(&sk->sk_write_queue);