From patchwork Mon Mar 14 08:43:02 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 12779882 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 B3111C433EF for ; Mon, 14 Mar 2022 08:43:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237644AbiCNIoV (ORCPT ); Mon, 14 Mar 2022 04:44:21 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60992 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235340AbiCNIoS (ORCPT ); Mon, 14 Mar 2022 04:44:18 -0400 Received: from mail-wm1-x32d.google.com (mail-wm1-x32d.google.com [IPv6:2a00:1450:4864:20::32d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 07F8D11C2E for ; Mon, 14 Mar 2022 01:43:08 -0700 (PDT) Received: by mail-wm1-x32d.google.com with SMTP id i66so8818741wma.5 for ; Mon, 14 Mar 2022 01:43:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=h8sJyHrz9MSFv6aQ5rNLhY6H2EgY9rxFKZSrrjXt/DA=; b=SFQws5dWS5IMGrfAnDPxae+Am8l7I6/hNpKN2OmjbEYBGOqYImlF1vqLR1AWOKjxuz Y3SmnYVN3rl4rC4EoSP+NPG+5KWZz++GAzeOoGAbPT/KVHXn4ANsb5wfn5v3kGdtF/ZJ 64EyjWFnJczi6FbxWHPRo3MnjGRwix9kCikrysBaeN1/ylzG2nUNblB3tW3v/OKTS6xt gCceRq2GOmUuCVyDsRt62GwnhO3ZZLyEg6TLLo0DIi2fWEIRL1kSiGcyV/KP1hV5Ur/m w9PIORH6GoAPa2fq9IRxdWhZhrnbnpECthh2qm72hq+KeXISV48tviEmpezl7l3KW+gs s/OA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=h8sJyHrz9MSFv6aQ5rNLhY6H2EgY9rxFKZSrrjXt/DA=; b=dTBvs3FdC5JPvwpKSclJFr7dT1z/el7D7eF9Fj5Bt6E2bioXgepNy0iMd/1i6VDf55 Da/ipouMBntWSv85wjWb4F0AvvgnX6KdTJm68ZiqHYBEA9dNZyOGLY1yHxqtup0ikcKg 2lboKVTM1VXx4bmKfF4uIsOkFqDSRtM+t8tUxfUrjKmJRjE8vWs0z5Pg4ETs16rNge7o edMBHgrakbd8Ccq0DEC2owiF3Eeqei8MrHyp4FfMkejWiMk9Y9qpf+TP1Oe1rUgAVtIN qR96B3Sr8qSVmwz2XJx2zJG5tbeJjhJqU/LQ4S2sUmh60t7i7KBUCC/ZGKbiLGhP5SSy xA6w== X-Gm-Message-State: AOAM531TTWvQQWG7G/xoTYV6zxR4RX/9LNwy7uJUcmTqUIMy5f9yg0jO +KwvBBEM/irVJnJAioMchCsF/w== X-Google-Smtp-Source: ABdhPJzc9uprjBGpnv4mgjX60WyBxgufdLW4uQZcYLKXmRnyMUHGBSCkV5UyRJf8/ADueYqZriWJIQ== X-Received: by 2002:a05:600c:4249:b0:385:a7bc:b37 with SMTP id r9-20020a05600c424900b00385a7bc0b37mr24170451wmm.185.1647247386565; Mon, 14 Mar 2022 01:43:06 -0700 (PDT) Received: from joneslee.c.googlers.com.com (205.215.190.35.bc.googleusercontent.com. [35.190.215.205]) by smtp.gmail.com with ESMTPSA id v14-20020adfd18e000000b0020373e5319asm13416678wrc.103.2022.03.14.01.43.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 14 Mar 2022 01:43:06 -0700 (PDT) From: Lee Jones To: lee.jones@linaro.org, mst@redhat.com, jasowang@redhat.com Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Date: Mon, 14 Mar 2022 08:43:02 +0000 Message-Id: <20220314084302.2933167-1-lee.jones@linaro.org> X-Mailer: git-send-email 2.35.1.723.g4982287a31-goog MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org vhost_vsock_handle_tx_kick() already holds the mutex during its call to vhost_get_vq_desc(). All we have to do here is take the same lock during virtqueue clean-up and we mitigate the reported issues. Also WARN() as a precautionary measure. The purpose of this is to capture possible future race conditions which may pop up over time. Cc: Signed-off-by: Lee Jones --- drivers/vhost/vhost.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 59edb5a1ffe28..bbaff6a5e21b8 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -693,6 +693,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) int i; for (i = 0; i < dev->nvqs; ++i) { + mutex_lock(&dev->vqs[i]->mutex); if (dev->vqs[i]->error_ctx) eventfd_ctx_put(dev->vqs[i]->error_ctx); if (dev->vqs[i]->kick) @@ -700,6 +701,7 @@ void vhost_dev_cleanup(struct vhost_dev *dev) if (dev->vqs[i]->call_ctx.ctx) eventfd_ctx_put(dev->vqs[i]->call_ctx.ctx); vhost_vq_reset(dev, dev->vqs[i]); + mutex_unlock(&dev->vqs[i]->mutex); } vhost_dev_free_iovecs(dev); if (dev->log_ctx)