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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 78B15C77B7D for ; Sat, 20 May 2023 18:22:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231963AbjETSWU (ORCPT ); Sat, 20 May 2023 14:22:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231938AbjETSV5 (ORCPT ); Sat, 20 May 2023 14:21:57 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7B5D910EC; Sat, 20 May 2023 11:21:37 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id BED2960EFA; Sat, 20 May 2023 18:21:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 688D3C433D2; Sat, 20 May 2023 18:21:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1684606878; bh=CuKgPgV6aZ3NzUMUfu26ivUi3ak9kLb/FiLkOUerykQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZSEJHIMD65qHE7urlgBofOUOYkh6TmO/7ShT+Hf9BeXWdyhf/Xu016kH04f31CzYQ WgsdBufzCdqgPl1h3NjmALpBDGtzNdGOqL9d5Qi4o+jBFKFH3vb/y2MsLDeRlqDAtw 6+MC7efR19BYwACdt2PYs155AxQvRc1Y/+HdBs+Svskyid7U0+/cZIE5H8DQmJSn0m A7mlEV0lOBRiS1JU9tC7J0l4t6HO6Sye8WoLIUKyCXFA0dCiwB/SHZP/tQvVKo4fZh lui+aa/zSnxbyrjBvszd+uC+FYPNvJXB682Uj990Ys6XSTurwtVZhOBnpvPkUHODsF ZQvqrrBl0j05Q== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Liming Sun , Vadim Pasternak , Hans de Goede , Sasha Levin , markgross@kernel.org, platform-driver-x86@vger.kernel.org Subject: [PATCH AUTOSEL 6.1 07/14] platform/mellanox: fix potential race in mlxbf-tmfifo driver Date: Sat, 20 May 2023 14:20:35 -0400 Message-Id: <20230520182044.836702-7-sashal@kernel.org> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20230520182044.836702-1-sashal@kernel.org> References: <20230520182044.836702-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Liming Sun [ Upstream commit 3d43f9f639542fadfb28f40b509bf147a6624d48 ] This commit adds memory barrier for the 'vq' update in function mlxbf_tmfifo_virtio_find_vqs() to avoid potential race due to out-of-order memory write. It also adds barrier for the 'is_ready' flag to make sure the initializations are visible before this flag is checked. Signed-off-by: Liming Sun Reviewed-by: Vadim Pasternak Link: https://lore.kernel.org/r/b98c0ab61d644ba38fa9b3fd1607b138b0dd820b.1682518748.git.limings@nvidia.com Signed-off-by: Hans de Goede Signed-off-by: Sasha Levin --- drivers/platform/mellanox/mlxbf-tmfifo.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/platform/mellanox/mlxbf-tmfifo.c b/drivers/platform/mellanox/mlxbf-tmfifo.c index 1ae3c56b66b09..b2e19f30a928b 100644 --- a/drivers/platform/mellanox/mlxbf-tmfifo.c +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c @@ -765,7 +765,7 @@ static void mlxbf_tmfifo_rxtx(struct mlxbf_tmfifo_vring *vring, bool is_rx) fifo = vring->fifo; /* Return if vdev is not ready. */ - if (!fifo->vdev[devid]) + if (!fifo || !fifo->vdev[devid]) return; /* Return if another vring is running. */ @@ -961,9 +961,13 @@ static int mlxbf_tmfifo_virtio_find_vqs(struct virtio_device *vdev, vq->num_max = vring->num; + vq->priv = vring; + + /* Make vq update visible before using it. */ + virtio_mb(false); + vqs[i] = vq; vring->vq = vq; - vq->priv = vring; } return 0; @@ -1260,6 +1264,9 @@ static int mlxbf_tmfifo_probe(struct platform_device *pdev) mod_timer(&fifo->timer, jiffies + MLXBF_TMFIFO_TIMER_INTERVAL); + /* Make all updates visible before setting the 'is_ready' flag. */ + virtio_mb(false); + fifo->is_ready = true; return 0; -- 2.39.2