From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A6D66C00140 for ; Fri, 5 Aug 2022 16:20:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241108AbiHEQUw (ORCPT ); Fri, 5 Aug 2022 12:20:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237618AbiHEQUs (ORCPT ); Fri, 5 Aug 2022 12:20:48 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4C350FD15 for ; Fri, 5 Aug 2022 09:20:47 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oK03V-0005OB-Nj; Fri, 05 Aug 2022 18:20:09 +0200 Received: from ore by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1oK03U-0006lP-71; Fri, 05 Aug 2022 18:20:08 +0200 Date: Fri, 5 Aug 2022 18:20:08 +0200 From: Oleksij Rempel To: Fedor Pchelkin Cc: Robin van der Gracht , ldv-project@linuxtesting.org, Oliver Hartkopp , linux-can@vger.kernel.org, Eric Dumazet , Marc Kleine-Budde , Alexey Khoroshilov , kernel@pengutronix.de, netdev@vger.kernel.org, Jakub Kicinski , Paolo Abeni , "David S . Miller" , linux-kernel@vger.kernel.org Subject: Re: [PATCH] can: j1939: fix memory leak of skbs Message-ID: <20220805162008.GA2585@pengutronix.de> References: <20220805150216.66313-1-pchelkin@ispras.ru> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20220805150216.66313-1-pchelkin@ispras.ru> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 05, 2022 at 06:02:16PM +0300, Fedor Pchelkin wrote: > We need to drop skb references taken in j1939_session_skb_queue() when > destroying a session in j1939_session_destroy(). Otherwise those skbs > would be lost. > > Link to Syzkaller info and repro: https://forge.ispras.ru/issues/11743. > > Found by Linux Verification Center (linuxtesting.org) with Syzkaller. > > Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") > Suggested-by: Oleksij Rempel > Signed-off-by: Fedor Pchelkin > Signed-off-by: Alexey Khoroshilov Acked-by: Oleksij Rempel > --- > net/can/j1939/transport.c | 8 +++++++- > 1 file changed, 7 insertions(+), 1 deletion(-) > > diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c > index 307ee1174a6e..d7d86c944d76 100644 > --- a/net/can/j1939/transport.c > +++ b/net/can/j1939/transport.c > @@ -260,6 +260,8 @@ static void __j1939_session_drop(struct j1939_session *session) > > static void j1939_session_destroy(struct j1939_session *session) > { > + struct sk_buff *skb; > + > if (session->transmission) { > if (session->err) > j1939_sk_errqueue(session, J1939_ERRQUEUE_TX_ABORT); > @@ -274,7 +276,11 @@ static void j1939_session_destroy(struct j1939_session *session) > WARN_ON_ONCE(!list_empty(&session->sk_session_queue_entry)); > WARN_ON_ONCE(!list_empty(&session->active_session_list_entry)); > > - skb_queue_purge(&session->skb_queue); > + while ((skb = skb_dequeue(&session->skb_queue)) != NULL) { > + /* drop ref taken in j1939_session_skb_queue() */ > + skb_unref(skb); > + kfree_skb(skb); > + } > __j1939_session_drop(session); > j1939_priv_put(session->priv); > kfree(session); > -- > 2.25.1 > > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |