From patchwork Thu Mar 14 22:49:06 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Jason A. Donenfeld" X-Patchwork-Id: 13592787 X-Patchwork-Delegate: kuba@kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 00366DDB7 for ; Thu, 14 Mar 2024 22:49:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710456572; cv=none; b=Z3DtRiVEy24/WDIcTgS2iswaAYXKMD7dF9sDZLjsuckWJUvgEaC+sy3M3Cs55xzmfQga4u7D0pid+purbHLYBpYRjoh/wwrEV+mb97dQv/2FKFhwH58QiDdJ87bszGavYbCK9oBWrulL7KQVxa4wmKD/aoJpBzmyF/PF0Grj7+8= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710456572; c=relaxed/simple; bh=kDEsIrg6Nol8QzsT5eioSka1ZUvLJR8G3JUJXLZ4YSE=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GT4+zXplH3k8+Bg+pPncNnsEErsqaaGXYKn6STXChiNHckhEF5cBWNzDqzdYQZznpejfBHdEPRYbAX4bctpDpSf3HGPFnkdsaZwLQJu+MMmc/DqEayk2BUOqzAw87ye9RUcDAjDHSFJGFx+fXvgh+svVFAu3V2m/FT22kQcEd5w= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b=JRn3z+Ce; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="JRn3z+Ce" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1B38CC43394; Thu, 14 Mar 2024 22:49:31 +0000 (UTC) Authentication-Results: smtp.kernel.org; dkim=pass (1024-bit key) header.d=zx2c4.com header.i=@zx2c4.com header.b="JRn3z+Ce" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=zx2c4.com; s=20210105; t=1710456569; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R9TXL22rgEgfNPNTOX7FofZ4jip3awg0IVdEpjuRqRM=; b=JRn3z+Ce5bxY2eZf3mbQ1XFjJ3RbnuHC0exfBSZEvRl+v9IBJpzMdVTzVkILsOTbTllghx oYxct13qriayhp6gwiFG4D1hqiQ0IwLecS1ziv0WplBADn1zvmT9nhagdrKSG5VOwHOndw tB+mlbt3xVqSB4jFvfeWu9lt1+zKmMc= Received: by mail.zx2c4.com (ZX2C4 Mail Server) with ESMTPSA id bcf8cf5e (TLSv1.3:TLS_AES_256_GCM_SHA384:256:NO); Thu, 14 Mar 2024 22:49:29 +0000 (UTC) From: "Jason A. Donenfeld" To: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org Subject: [PATCH net 1/6] wireguard: receive: annotate data-race around receiving_counter.counter Date: Thu, 14 Mar 2024 16:49:06 -0600 Message-ID: <20240314224911.6653-2-Jason@zx2c4.com> In-Reply-To: <20240314224911.6653-1-Jason@zx2c4.com> References: <20240314224911.6653-1-Jason@zx2c4.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org From: Nikita Zhandarovich Syzkaller with KCSAN identified a data-race issue when accessing keypair->receiving_counter.counter. Use READ_ONCE() and WRITE_ONCE() annotations to mark the data race as intentional. 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 Signed-off-by: Jason A. Donenfeld --- drivers/net/wireguard/receive.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireguard/receive.c b/drivers/net/wireguard/receive.c index df275b4fccb6..eb8851113654 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; @@ -463,7 +463,7 @@ int wg_packet_rx_poll(struct napi_struct *napi, int budget) net_dbg_ratelimited("%s: Packet has invalid nonce %llu (max %llu)\n", peer->device->dev->name, PACKET_CB(skb)->nonce, - keypair->receiving_counter.counter); + READ_ONCE(keypair->receiving_counter.counter)); goto next; }