From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:58352 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbdBXIiq (ORCPT ); Fri, 24 Feb 2017 03:38:46 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dmitry Vyukov , Tom Herbert , Cong Wang , "David S. Miller" Subject: [PATCH 4.9 02/32] kcm: fix a null pointer dereference in kcm_sendmsg() Date: Fri, 24 Feb 2017 09:37:46 +0100 Message-Id: <20170224083746.679974411@linuxfoundation.org> In-Reply-To: <20170224083746.364657938@linuxfoundation.org> References: <20170224083746.364657938@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: WANG Cong [ Upstream commit cd27b96bc13841ee7af25837a6ae86fee87273d6 ] In commit 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()") I tried to avoid skb allocation for 0-length case, but missed a check for NULL pointer in the non EOR case. Fixes: 98e3862ca2b1 ("kcm: fix 0-length case for kcm_sendmsg()") Reported-by: Dmitry Vyukov Cc: Tom Herbert Signed-off-by: Cong Wang Acked-by: Tom Herbert Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/kcm/kcmsock.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/net/kcm/kcmsock.c +++ b/net/kcm/kcmsock.c @@ -1044,8 +1044,10 @@ wait_for_memory: } else { /* Message not complete, save state */ partial_message: - kcm->seq_skb = head; - kcm_tx_msg(head)->last_skb = skb; + if (head) { + kcm->seq_skb = head; + kcm_tx_msg(head)->last_skb = skb; + } } KCM_STATS_ADD(kcm->stats.tx_bytes, copied);