From patchwork Tue Oct 17 08:37:23 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Steffen Klassert X-Patchwork-Id: 13424792 X-Patchwork-Delegate: kuba@kernel.org Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D63B33B7BB for ; Tue, 17 Oct 2023 08:37:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from a.mx.secunet.com (a.mx.secunet.com [62.96.220.36]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1CD45B0 for ; Tue, 17 Oct 2023 01:37:34 -0700 (PDT) Received: from localhost (localhost [127.0.0.1]) by a.mx.secunet.com (Postfix) with ESMTP id 55AAF206B0; Tue, 17 Oct 2023 10:37:30 +0200 (CEST) X-Virus-Scanned: by secunet Received: from a.mx.secunet.com ([127.0.0.1]) by localhost (a.mx.secunet.com [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AfexP6KKC1cu; Tue, 17 Oct 2023 10:37:29 +0200 (CEST) Received: from mailout2.secunet.com (mailout2.secunet.com [62.96.220.49]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by a.mx.secunet.com (Postfix) with ESMTPS id 71CDD20851; Tue, 17 Oct 2023 10:37:28 +0200 (CEST) Received: from cas-essen-02.secunet.de (unknown [10.53.40.202]) by mailout2.secunet.com (Postfix) with ESMTP id 6FBEB80004A; Tue, 17 Oct 2023 10:37:28 +0200 (CEST) Received: from mbx-essen-02.secunet.de (10.53.40.198) by cas-essen-02.secunet.de (10.53.40.202) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.32; Tue, 17 Oct 2023 10:37:28 +0200 Received: from gauss2.secunet.de (10.182.7.193) by mbx-essen-02.secunet.de (10.53.40.198) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.32; Tue, 17 Oct 2023 10:37:27 +0200 Received: by gauss2.secunet.de (Postfix, from userid 1000) id 8917E3182AD2; Tue, 17 Oct 2023 10:37:26 +0200 (CEST) From: Steffen Klassert To: David Miller , Jakub Kicinski CC: Herbert Xu , Steffen Klassert , Subject: [PATCH 7/7] xfrm: fix a data-race in xfrm_lookup_with_ifid() Date: Tue, 17 Oct 2023 10:37:23 +0200 Message-ID: <20231017083723.1364940-8-steffen.klassert@secunet.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20231017083723.1364940-1-steffen.klassert@secunet.com> References: <20231017083723.1364940-1-steffen.klassert@secunet.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ClientProxiedBy: cas-essen-02.secunet.de (10.53.40.202) To mbx-essen-02.secunet.de (10.53.40.198) X-EXCLAIMER-MD-CONFIG: 2c86f778-e09b-4440-8b15-867914633a10 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org From: Eric Dumazet syzbot complains about a race in xfrm_lookup_with_ifid() [1] When preparing commit 0a9e5794b21e ("xfrm: annotate data-race around use_time") I thought xfrm_lookup_with_ifid() was modifying a still private structure. [1] BUG: KCSAN: data-race in xfrm_lookup_with_ifid / xfrm_lookup_with_ifid write to 0xffff88813ea41108 of 8 bytes by task 8150 on cpu 1: xfrm_lookup_with_ifid+0xce7/0x12d0 net/xfrm/xfrm_policy.c:3218 xfrm_lookup net/xfrm/xfrm_policy.c:3270 [inline] xfrm_lookup_route+0x3b/0x100 net/xfrm/xfrm_policy.c:3281 ip6_dst_lookup_flow+0x98/0xc0 net/ipv6/ip6_output.c:1246 send6+0x241/0x3c0 drivers/net/wireguard/socket.c:139 wg_socket_send_skb_to_peer+0xbd/0x130 drivers/net/wireguard/socket.c:178 wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 write to 0xffff88813ea41108 of 8 bytes by task 15867 on cpu 0: xfrm_lookup_with_ifid+0xce7/0x12d0 net/xfrm/xfrm_policy.c:3218 xfrm_lookup net/xfrm/xfrm_policy.c:3270 [inline] xfrm_lookup_route+0x3b/0x100 net/xfrm/xfrm_policy.c:3281 ip6_dst_lookup_flow+0x98/0xc0 net/ipv6/ip6_output.c:1246 send6+0x241/0x3c0 drivers/net/wireguard/socket.c:139 wg_socket_send_skb_to_peer+0xbd/0x130 drivers/net/wireguard/socket.c:178 wg_socket_send_buffer_to_peer+0xd6/0x100 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x10c/0x150 drivers/net/wireguard/send.c:51 process_one_work kernel/workqueue.c:2630 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2703 worker_thread+0x525/0x730 kernel/workqueue.c:2784 kthread+0x1d7/0x210 kernel/kthread.c:388 ret_from_fork+0x48/0x60 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 value changed: 0x00000000651cd9d1 -> 0x00000000651cd9d2 Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 15867 Comm: kworker/u4:58 Not tainted 6.6.0-rc4-syzkaller-00016-g5e62ed3b1c8a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023 Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker Fixes: 0a9e5794b21e ("xfrm: annotate data-race around use_time") Reported-by: syzbot Signed-off-by: Eric Dumazet Cc: Steffen Klassert Signed-off-by: Steffen Klassert --- net/xfrm/xfrm_policy.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index 99df2862bdc9..d24b4d4f620e 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -3220,7 +3220,7 @@ struct dst_entry *xfrm_lookup_with_ifid(struct net *net, } for (i = 0; i < num_pols; i++) - pols[i]->curlft.use_time = ktime_get_real_seconds(); + WRITE_ONCE(pols[i]->curlft.use_time, ktime_get_real_seconds()); if (num_xfrms < 0) { /* Prohibit the flow */