From patchwork Fri Aug 5 15:02:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Fedor Pchelkin X-Patchwork-Id: 12937396 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 3DAF2C25B08 for ; Fri, 5 Aug 2022 15:03:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238553AbiHEPDe (ORCPT ); Fri, 5 Aug 2022 11:03:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52536 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241142AbiHEPDW (ORCPT ); Fri, 5 Aug 2022 11:03:22 -0400 Received: from mail.ispras.ru (mail.ispras.ru [83.149.199.84]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 908593AB; Fri, 5 Aug 2022 08:02:33 -0700 (PDT) Received: from localhost.localdomain (unknown [83.149.199.65]) by mail.ispras.ru (Postfix) with ESMTPSA id 9C66C40755C7; Fri, 5 Aug 2022 15:02:31 +0000 (UTC) From: Fedor Pchelkin To: Oleksij Rempel , Robin van der Gracht Cc: Fedor Pchelkin , kernel@pengutronix.de, Oliver Hartkopp , Marc Kleine-Budde , "David S . Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , linux-can@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org, Alexey Khoroshilov Subject: [PATCH] can: j1939: fix memory leak of skbs Date: Fri, 5 Aug 2022 18:02:16 +0300 Message-Id: <20220805150216.66313-1-pchelkin@ispras.ru> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org 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);