From mboxrd@z Thu Jan 1 00:00:00 1970 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 E846410FC for ; Wed, 7 Jun 2023 20:26:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 65A5DC433EF; Wed, 7 Jun 2023 20:26:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1686169574; bh=OXkMsN4v3FFJULQWV4/kyARqFXtJzpyCewzKLaeiJl8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ryub4uwxfyWi9Rf4BhQBGK7OWapQ+xsNWwn8UwGnMpaOqByIzZpUwaZvEo8RW18Xb F0hg0kOC6zld0JIMGUoPrj/TrlsxtW2/bmZLjj2PiBNHoWgquWIDjzrUjj7SIH4sA+ 4AjyMZ089LiKK+alhfxfEOW2VeJDDgkjma1zo6I4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Liming Sun , Vadim Pasternak , Hans de Goede , Sasha Levin Subject: [PATCH 6.3 103/286] platform/mellanox: fix potential race in mlxbf-tmfifo driver Date: Wed, 7 Jun 2023 22:13:22 +0200 Message-ID: <20230607200926.432451885@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230607200922.978677727@linuxfoundation.org> References: <20230607200922.978677727@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 91a077c35b8b8..a79318e90a139 100644 --- a/drivers/platform/mellanox/mlxbf-tmfifo.c +++ b/drivers/platform/mellanox/mlxbf-tmfifo.c @@ -784,7 +784,7 @@ 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. */ @@ -980,9 +980,13 @@ 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; @@ -1302,6 +1306,9 @@ 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