Patch "dccp: CVE-2017-8824: use-after-free in DCCP code" has been added to the 4.4-stable tree

gregkh
2018-02-13T16:35:27Z

This is a note to let you know that I've just added the patch titled

dccp: CVE-2017-8824: use-after-free in DCCP code

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
dccp-cve-2017-8824-use-after-free-in-dccp-code.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.

>From 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 Mon Sep 17 00:00:00 2001
From: Mohamed Ghannam <simo.ghannam@gmail.com>
Date: Tue, 5 Dec 2017 20:58:35 +0000
Subject: dccp: CVE-2017-8824: use-after-free in DCCP code

From: Mohamed Ghannam <simo.ghannam@gmail.com>

commit 69c64866ce072dea1d1e59a0d61e0f66c0dffb76 upstream.

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 <simo.ghannam@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
net/dccp/proto.c | 5 +++++
1 file changed, 5 insertions(+)

--- a/net/dccp/proto.c
+++ b/net/dccp/proto.c
@@ -259,6 +259,7 @@ int dccp_disconnect(struct sock *sk, int
{
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
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);

Patches currently in stable-queue which might be from simo.ghannam@gmail.com are

queue-4.4/dccp-cve-2017-8824-use-after-free-in-dccp-code.patch