From patchwork Tue Aug 9 07:53:15 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 12939407 X-Patchwork-Delegate: kuba@kernel.org 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 F1E13C19F2D for ; Tue, 9 Aug 2022 07:54:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239681AbiHIHyy (ORCPT ); Tue, 9 Aug 2022 03:54:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41258 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240157AbiHIHyt (ORCPT ); Tue, 9 Aug 2022 03:54:49 -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 15A3721809 for ; Tue, 9 Aug 2022 00:54:48 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oLK4c-0000UT-EN for netdev@vger.kernel.org; Tue, 09 Aug 2022 09:54:46 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id AA64AC558C for ; Tue, 9 Aug 2022 07:53:21 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id E7E73C556B; Tue, 9 Aug 2022 07:53:20 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 24fe071f; Tue, 9 Aug 2022 07:53:19 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Fedor Pchelkin , Oleksij Rempel , Alexey Khoroshilov , Marc Kleine-Budde Subject: [PATCH net 2/4] can: j1939: j1939_session_destroy(): fix memory leak of skbs Date: Tue, 9 Aug 2022 09:53:15 +0200 Message-Id: <20220809075317.1549323-3-mkl@pengutronix.de> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220809075317.1549323-1-mkl@pengutronix.de> References: <20220809075317.1549323-1-mkl@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org From: Fedor Pchelkin 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. V1: https://lore.kernel.org/all/20220708175949.539064-1-pchelkin@ispras.ru 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 Link: https://lore.kernel.org/all/20220805150216.66313-1-pchelkin@ispras.ru Signed-off-by: Marc Kleine-Budde --- 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);