From patchwork Fri Sep 3 15:25:01 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thadeu Lima de Souza Cascardo X-Patchwork-Id: 1524376 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=canonical.com header.i=@canonical.com header.a=rsa-sha256 header.s=20210705 header.b=QANOEkMs; dkim-atps=neutral Authentication-Results: ozlabs.org; spf=none (no SPF record) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 4H1M6z5bwrz9sW4; Sat, 4 Sep 2021 01:25:14 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1mMB41-00073B-Qh; Fri, 03 Sep 2021 15:25:09 +0000 Received: from smtp-relay-canonical-0.internal ([10.131.114.83] helo=smtp-relay-canonical-0.canonical.com) by huckleberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1mMB40-00072z-DL for kernel-team@lists.ubuntu.com; Fri, 03 Sep 2021 15:25:08 +0000 Received: from mussarela.. (201-69-234-220.dial-up.telesp.net.br [201.69.234.220]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-canonical-0.canonical.com (Postfix) with ESMTPSA id 947BF401A6 for ; Fri, 3 Sep 2021 15:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=canonical.com; s=20210705; t=1630682708; bh=TjaKngEPmlNAQ2z0BgvGElPYrIuTv/O5a59tsuKcjhI=; h=From:To:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=QANOEkMsVs1st6DBOA0syjhF6Nd2sy/bgsRnmhSQfm2ua2NKirM6upUpk+S44ban9 au9x4IHisuVXxILBiLMkkByGhxlgLK2dIrXKl7bcfWMH6RMD1+77OohTvSv08zMxGm yIWrVY3EnTP3zQaNX9EKFzh9Qcjml3cRhJbIUhnhmcqel1p5CfYjK5BdFfOnxuGgIJ zqYl7LxaNucRf5wmYSilG/xye59l284OTj0Dd2ZQlwtYjcI6uXLAQ8a1oYXs4smaIf u07+vN8tdVpMv+Cpx9is2czDhgZ1BQwwns0+06li0XkN0faihEpKgsf/ewEBdLElYD UddOAyjqXaH2Q== From: Thadeu Lima de Souza Cascardo To: kernel-team@lists.ubuntu.com Subject: [SRU Focal/linux-hwe-5.13 2/2] can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done Date: Fri, 3 Sep 2021 12:25:01 -0300 Message-Id: <20210903152501.61335-3-cascardo@canonical.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20210903152501.61335-1-cascardo@canonical.com> References: <20210903152501.61335-1-cascardo@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Oleksij Rempel Set SOCK_RCU_FREE to let RCU to call sk_destruct() on completion. Without this patch, we will run in to j1939_can_recv() after priv was freed by j1939_sk_release()->j1939_sk_sock_destruct() Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback") Link: https://lore.kernel.org/r/20210617130623.12705-1-o.rempel@pengutronix.de Cc: linux-stable Reported-by: Thadeu Lima de Souza Cascardo Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com Signed-off-by: Oleksij Rempel Signed-off-by: Marc Kleine-Budde (cherry picked from commit 22c696fed25c63c7f67508309820358b94a96b6d) CVE-2021-3609 Signed-off-by: Thadeu Lima de Souza Cascardo --- net/can/j1939/main.c | 4 ++++ net/can/j1939/socket.c | 3 +++ 2 files changed, 7 insertions(+) diff --git a/net/can/j1939/main.c b/net/can/j1939/main.c index da3a7a7bcff2..08c8606cfd9c 100644 --- a/net/can/j1939/main.c +++ b/net/can/j1939/main.c @@ -193,6 +193,10 @@ static void j1939_can_rx_unregister(struct j1939_priv *priv) can_rx_unregister(dev_net(ndev), ndev, J1939_CAN_ID, J1939_CAN_MASK, j1939_can_recv, priv); + /* The last reference of priv is dropped by the RCU deferred + * j1939_sk_sock_destruct() of the last socket, so we can + * safely drop this reference here. + */ j1939_priv_put(priv); } diff --git a/net/can/j1939/socket.c b/net/can/j1939/socket.c index 56aa66147d5a..fce8bc8afeb7 100644 --- a/net/can/j1939/socket.c +++ b/net/can/j1939/socket.c @@ -398,6 +398,9 @@ static int j1939_sk_init(struct sock *sk) atomic_set(&jsk->skb_pending, 0); spin_lock_init(&jsk->sk_session_queue_lock); INIT_LIST_HEAD(&jsk->sk_session_queue); + + /* j1939_sk_sock_destruct() depends on SOCK_RCU_FREE flag */ + sock_set_flag(sk, SOCK_RCU_FREE); sk->sk_destruct = j1939_sk_sock_destruct; sk->sk_protocol = CAN_J1939;