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 lists.zx2c4.com (lists.zx2c4.com [165.227.139.114]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id D49B7C47077 for ; Thu, 11 Jan 2024 15:41:48 +0000 (UTC) Received: by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTP id 12fda47e; Thu, 11 Jan 2024 15:41:46 +0000 (UTC) Received: from exchange.fintech.ru (exchange.fintech.ru [195.54.195.159]) by lists.zx2c4.com (ZX2C4 Mail Server) with ESMTPS id 6dc31836 (TLSv1.2:ECDHE-ECDSA-AES256-GCM-SHA384:256:NO) for ; Thu, 11 Jan 2024 15:41:45 +0000 (UTC) Received: from Ex16-01.fintech.ru (10.0.10.18) by exchange.fintech.ru (195.54.195.159) with Microsoft SMTP Server (TLS) id 14.3.498.0; Thu, 11 Jan 2024 18:41:44 +0300 Received: from localhost (10.0.253.138) by Ex16-01.fintech.ru (10.0.10.18) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2242.4; Thu, 11 Jan 2024 18:41:43 +0300 From: Nikita Zhandarovich To: "Jason A. Donenfeld" , "David S. Miller" , Eric Dumazet CC: Nikita Zhandarovich , Jakub Kicinski , Paolo Abeni , , , , syzbot , Subject: [PATCH net] wireguard: receive: annotate data-race around receiving_counter.counter Date: Thu, 11 Jan 2024 07:41:38 -0800 Message-ID: <20240111154138.7605-1-n.zhandarovich@fintech.ru> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.0.253.138] X-ClientProxiedBy: Ex16-02.fintech.ru (10.0.10.19) To Ex16-01.fintech.ru (10.0.10.18) X-BeenThere: wireguard@lists.zx2c4.com X-Mailman-Version: 2.1.30rc1 Precedence: list List-Id: Development discussion of WireGuard List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: wireguard-bounces@lists.zx2c4.com Sender: "WireGuard" Syzkaller with KCSAN identified a data-race issue [1] when accessing keypair->receiving_counter.counter. This patch uses READ_ONCE() and WRITE_ONCE() annotations to fix the problem. [1] BUG: KCSAN: data-race in wg_packet_decrypt_worker / wg_packet_rx_poll write to 0xffff888107765888 of 8 bytes by interrupt on cpu 0: counter_validate drivers/net/wireguard/receive.c:321 [inline] wg_packet_rx_poll+0x3ac/0xf00 drivers/net/wireguard/receive.c:461 __napi_poll+0x60/0x3b0 net/core/dev.c:6536 napi_poll net/core/dev.c:6605 [inline] net_rx_action+0x32b/0x750 net/core/dev.c:6738 __do_softirq+0xc4/0x279 kernel/softirq.c:553 do_softirq+0x5e/0x90 kernel/softirq.c:454 __local_bh_enable_ip+0x64/0x70 kernel/softirq.c:381 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:167 [inline] _raw_spin_unlock_bh+0x36/0x40 kernel/locking/spinlock.c:210 spin_unlock_bh include/linux/spinlock.h:396 [inline] ptr_ring_consume_bh include/linux/ptr_ring.h:367 [inline] wg_packet_decrypt_worker+0x6c5/0x700 drivers/net/wireguard/receive.c:499 process_one_work kernel/workqueue.c:2633 [inline] ... read to 0xffff888107765888 of 8 bytes by task 3196 on cpu 1: decrypt_packet drivers/net/wireguard/receive.c:252 [inline] wg_packet_decrypt_worker+0x220/0x700 drivers/net/wireguard/receive.c:501 process_one_work kernel/workqueue.c:2633 [inline] process_scheduled_works+0x5b8/0xa30 kernel/workqueue.c:2706 worker_thread+0x525/0x730 kernel/workqueue.c:2787 ... Fixes: a9e90d9931f3 ("wireguard: noise: separate receive counter from send counter") Reported-by: syzbot+d1de830e4ecdaac83d89@syzkaller.appspotmail.com Signed-off-by: Nikita Zhandarovich --- drivers/net/wireguard/receive.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index a176653c8861..d91383afb6e2 100644 --- a/drivers/net/wireguard/receive.c +++ b/drivers/net/wireguard/receive.c @@ -251,7 +251,7 @@ static bool decrypt_packet(struct sk_buff *skb, struct noise_keypair *keypair) if (unlikely(!READ_ONCE(keypair->receiving.is_valid) || wg_birthdate_has_expired(keypair->receiving.birthdate, REJECT_AFTER_TIME) || - keypair->receiving_counter.counter >= REJECT_AFTER_MESSAGES)) { + READ_ONCE(keypair->receiving_counter.counter) >= REJECT_AFTER_MESSAGES)) { WRITE_ONCE(keypair->receiving.is_valid, false); return false; } @@ -318,7 +318,7 @@ static bool counter_validate(struct noise_replay_counter *counter, u64 their_cou for (i = 1; i <= top; ++i) counter->backtrack[(i + index_current) & ((COUNTER_BITS_TOTAL / BITS_PER_LONG) - 1)] = 0; - counter->counter = their_counter; + WRITE_ONCE(counter->counter, their_counter); } index &= (COUNTER_BITS_TOTAL / BITS_PER_LONG) - 1;