From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:59238 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750716AbeC2G1D (ORCPT ); Thu, 29 Mar 2018 02:27:03 -0400 Subject: Patch "dccp: check sk for closed state in dccp_sendmsg()" has been added to the 4.9-stable tree To: alexey.kodanev@oracle.com, davem@davemloft.net, gregkh@linuxfoundation.org Cc: , From: Date: Thu, 29 Mar 2018 08:26:59 +0200 Message-ID: <1522304819162141@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled dccp: check sk for closed state in dccp_sendmsg() to the 4.9-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-check-sk-for-closed-state-in-dccp_sendmsg.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From foo@baz Wed Mar 28 20:16:33 CEST 2018 From: Alexey Kodanev Date: Tue, 6 Mar 2018 22:57:01 +0300 Subject: dccp: check sk for closed state in dccp_sendmsg() From: Alexey Kodanev [ Upstream commit 67f93df79aeefc3add4e4b31a752600f834236e2 ] dccp_disconnect() sets 'dp->dccps_hc_tx_ccid' tx handler to NULL, therefore if DCCP socket is disconnected and dccp_sendmsg() is called after it, it will cause a NULL pointer dereference in dccp_write_xmit(). This crash and the reproducer was reported by syzbot. Looks like it is reproduced if commit 69c64866ce07 ("dccp: CVE-2017-8824: use-after-free in DCCP code") is applied. Reported-by: syzbot+f99ab3887ab65d70f816@syzkaller.appspotmail.com Signed-off-by: Alexey Kodanev Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dccp/proto.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -789,6 +789,11 @@ int dccp_sendmsg(struct sock *sk, struct if (skb == NULL) goto out_release; + if (sk->sk_state == DCCP_CLOSED) { + rc = -ENOTCONN; + goto out_discard; + } + skb_reserve(skb, sk->sk_prot->max_header); rc = memcpy_from_msg(skb_put(skb, len), msg, len); if (rc != 0) Patches currently in stable-queue which might be from alexey.kodanev@oracle.com are queue-4.9/sch_netem-fix-skb-leak-in-netem_enqueue.patch queue-4.9/dccp-check-sk-for-closed-state-in-dccp_sendmsg.patch