pve-edge-kernel/patches/kernel/0021-dccp-CVE-2017-8824-use-after-free-in-DCCP-code.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Mohamed Ghannam <[email protected]>
Date: Fri, 8 Dec 2017 15:39:50 +0100
Subject: [PATCH] dccp: CVE-2017-8824: use-after-free in DCCP code
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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 <[email protected]>
Reviewed-by: Eric Dumazet <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

CVE-2017-8824
(cherry picked from commit 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 linux-next)
Signed-off-by: Kleber Sacilotto de Souza <[email protected]>
Acked-by: Seth Forshee <[email protected]>
Acked-by: Colin Ian King <[email protected]>
Signed-off-by: Thadeu Lima de Souza Cascardo <[email protected]>
Signed-off-by: Fabian Grünbichler <[email protected]>
---
 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);
-- 
2.14.2