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 AA6CDC4332F for ; Mon, 7 Mar 2022 19:18:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S245031AbiCGTTB (ORCPT ); Mon, 7 Mar 2022 14:19:01 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46918 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237059AbiCGTS7 (ORCPT ); Mon, 7 Mar 2022 14:18:59 -0500 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 098FE10FC3 for ; Mon, 7 Mar 2022 11:18:00 -0800 (PST) Received: by mail-wm1-x32d.google.com with SMTP id bg31-20020a05600c3c9f00b00381590dbb33so43118wmb.3 for ; Mon, 07 Mar 2022 11:17:59 -0800 (PST) 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=dbqVSaoeE145ys9uRLEZZR3pFJY2Pmc5WG68rQTUDjk=; b=k5NesdgsXTht6dMH9Zs1gYWtYMsdq2oaoUryBtRQ299vTq+wKnD4nno1egKbIrBVvt u37JkSvL43u/gPcfLHEvrdES3On3K8okyZKtK5x2IaGkdK0XOr7WB7zQ9Zcbj6CmcmdK 9Q6QJ9Hpjk2XNo/+94qYcfJQzracg57M/trJW6e8B5gjvzvUh4ypNZwjQtF4ZxhHttPH RY9eQVjhbBd/2+kGoSzknYgZXbhAs5GglyD9L3X75TZDWmEoUhXsoTT0NkLyTmW4h/na S9CvMWfORnMzpWyVUpT8XabV69cJNTthtxd3VRYBNCWPUjkEEJsNFDT0CozCWgfN8F7p NcRQ== 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=dbqVSaoeE145ys9uRLEZZR3pFJY2Pmc5WG68rQTUDjk=; b=Och0XMCEltDLi4UvougGSUViMpstf/1L77X0qxNRi0Ux3zkVPqgi/mY+mexf1+F6g9 EL9lErBqXtOhUNYl5awMAiJmPUtnwGcNuoCnxHbm6qUEisW0uoOd1f+1Edcb+LaZ8GyJ wEz/HOPnKTRSlSi92DCi/zlDp1cwE0yuZ5mMIBWLQzg9WwZL9rvnluywUwBCG+eu5ZAd PSDSOkROIQVPsW/46dd0uOvtEwbgwrVgO26iZXPA8NNTCOondUUnUtT6S9w1NqaN9SP8 SNCorv2eSY/w06nJvzr0oRNMoAKKB3GN1oFnkLZ3lLlEizEAduW9ZC+uFpWuSZ3L6VBV H/2Q== X-Gm-Message-State: AOAM530b56zXp6y+G/ojvjOkdWJU+7hoJF9y3pupoHqiOmyGu2JdCjkY IOUDU+DfhR/L+7vBsqbY7boY0g== X-Google-Smtp-Source: ABdhPJzlJiMYAf08xQYWLIojU4uURtjWC9ZBAz30RgCGZ9HLvlLDJ9lUmbZ5j3Q/JntOftXy/SgAdQ== X-Received: by 2002:a05:600c:4615:b0:386:9f67:8c63 with SMTP id m21-20020a05600c461500b003869f678c63mr381658wmo.12.1646680678579; Mon, 07 Mar 2022 11:17:58 -0800 (PST) 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 p15-20020a05600c1d8f00b003899d50f01csm200741wms.6.2022.03.07.11.17.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Mar 2022 11:17:58 -0800 (PST) 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, syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com Subject: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Date: Mon, 7 Mar 2022 19:17:57 +0000 Message-Id: <20220307191757.3177139-1-lee.jones@linaro.org> X-Mailer: git-send-email 2.35.1.616.g0bdcbb4464-goog MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@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. Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00 Cc: Reported-by: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com Signed-off-by: Lee Jones --- drivers/vhost/vhost.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 59edb5a1ffe28..ef7e371e3e649 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -693,6 +693,15 @@ void vhost_dev_cleanup(struct vhost_dev *dev) int i; for (i = 0; i < dev->nvqs; ++i) { + /* No workers should run here by design. However, races have + * previously occurred where drivers have been unable to flush + * all work properly prior to clean-up. Without a successful + * flush the guest will malfunction, but avoiding host memory + * corruption in those cases does seem preferable. + */ + WARN_ON(mutex_is_locked(&dev->vqs[i]->mutex)); + + 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 +709,7 @@ 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) -- 2.35.1.616.g0bdcbb4464-goog 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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (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 1BBDDC433FE for ; Mon, 7 Mar 2022 19:18:04 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id AA62F401B6; Mon, 7 Mar 2022 19:18:04 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PuMC7Iatkx8T; Mon, 7 Mar 2022 19:18:03 +0000 (UTC) Received: from lists.linuxfoundation.org (lf-lists.osuosl.org [IPv6:2605:bc80:3010:104::8cd3:938]) by smtp4.osuosl.org (Postfix) with ESMTPS id 545CA401BA; Mon, 7 Mar 2022 19:18:03 +0000 (UTC) Received: from lf-lists.osuosl.org (localhost [127.0.0.1]) by lists.linuxfoundation.org (Postfix) with ESMTP id 12418C001D; Mon, 7 Mar 2022 19:18:03 +0000 (UTC) Received: from smtp1.osuosl.org (smtp1.osuosl.org [140.211.166.138]) by lists.linuxfoundation.org (Postfix) with ESMTP id ECA4DC000B for ; Mon, 7 Mar 2022 19:18:01 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp1.osuosl.org (Postfix) with ESMTP id C76DC82AC8 for ; Mon, 7 Mar 2022 19:18:01 +0000 (UTC) X-Virus-Scanned: amavisd-new at osuosl.org Authentication-Results: smtp1.osuosl.org (amavisd-new); dkim=pass (2048-bit key) header.d=linaro.org Received: from smtp1.osuosl.org ([127.0.0.1]) by localhost (smtp1.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id AsUwX45PPw4K for ; Mon, 7 Mar 2022 19:18:00 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.8.0 Received: from mail-wm1-x32e.google.com (mail-wm1-x32e.google.com [IPv6:2a00:1450:4864:20::32e]) by smtp1.osuosl.org (Postfix) with ESMTPS id 59C3882AA9 for ; Mon, 7 Mar 2022 19:18:00 +0000 (UTC) Received: by mail-wm1-x32e.google.com with SMTP id q20so7486395wmq.1 for ; Mon, 07 Mar 2022 11:18:00 -0800 (PST) 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=dbqVSaoeE145ys9uRLEZZR3pFJY2Pmc5WG68rQTUDjk=; b=k5NesdgsXTht6dMH9Zs1gYWtYMsdq2oaoUryBtRQ299vTq+wKnD4nno1egKbIrBVvt u37JkSvL43u/gPcfLHEvrdES3On3K8okyZKtK5x2IaGkdK0XOr7WB7zQ9Zcbj6CmcmdK 9Q6QJ9Hpjk2XNo/+94qYcfJQzracg57M/trJW6e8B5gjvzvUh4ypNZwjQtF4ZxhHttPH RY9eQVjhbBd/2+kGoSzknYgZXbhAs5GglyD9L3X75TZDWmEoUhXsoTT0NkLyTmW4h/na S9CvMWfORnMzpWyVUpT8XabV69cJNTthtxd3VRYBNCWPUjkEEJsNFDT0CozCWgfN8F7p NcRQ== 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=dbqVSaoeE145ys9uRLEZZR3pFJY2Pmc5WG68rQTUDjk=; b=6Ufx+Z7z08sg/dvtRia93hwvOg4hFK8RNn706RuC4RUD4bAuf2OKHg3acMzpOG3iUs Cjh9sAuIfdiRkZQhfBvO3IVIzxLHxa/G8G4ZDPSsMxkPbeOUUT4OUBGshwL8n32NJbsl pusM8eaOI18AICvxgv70r8hT/pozahr4yEyx1MnWYqsoXKy4niCgg72SWbU3jlO1UkET xqI6SNkCciIX20sxNJvWmacLOpc1f5G5RkWgpwVwZoyB7iyOZtqhITitc4M6Obu0px31 vzWSz4rVXNC6oCftSTYhlxlNkbn/qzqlt0AxOYs2O+6cujH09NY+yNdeHPwRKFTA6/uc G2ow== X-Gm-Message-State: AOAM533i/vHOzjw6eVZU8Igyhg5z7GOWguESBpx4WrBl4Fi6igtakFej ub9+W7KHQrfspgQjX7a8tdHIog== X-Google-Smtp-Source: ABdhPJzlJiMYAf08xQYWLIojU4uURtjWC9ZBAz30RgCGZ9HLvlLDJ9lUmbZ5j3Q/JntOftXy/SgAdQ== X-Received: by 2002:a05:600c:4615:b0:386:9f67:8c63 with SMTP id m21-20020a05600c461500b003869f678c63mr381658wmo.12.1646680678579; Mon, 07 Mar 2022 11:17:58 -0800 (PST) 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 p15-20020a05600c1d8f00b003899d50f01csm200741wms.6.2022.03.07.11.17.58 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Mar 2022 11:17:58 -0800 (PST) From: Lee Jones To: lee.jones@linaro.org, mst@redhat.com, jasowang@redhat.com Subject: [PATCH 1/1] vhost: Protect the virtqueue from being cleared whilst still in use Date: Mon, 7 Mar 2022 19:17:57 +0000 Message-Id: <20220307191757.3177139-1-lee.jones@linaro.org> X-Mailer: git-send-email 2.35.1.616.g0bdcbb4464-goog MIME-Version: 1.0 Cc: kvm@vger.kernel.org, netdev@vger.kernel.org, syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com, stable@vger.kernel.org, linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org X-BeenThere: virtualization@lists.linux-foundation.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: Linux virtualization List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: virtualization-bounces@lists.linux-foundation.org Sender: "Virtualization" 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. Link: https://syzkaller.appspot.com/bug?extid=279432d30d825e63ba00 Cc: Reported-by: syzbot+adc3cb32385586bec859@syzkaller.appspotmail.com Signed-off-by: Lee Jones --- drivers/vhost/vhost.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c index 59edb5a1ffe28..ef7e371e3e649 100644 --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -693,6 +693,15 @@ void vhost_dev_cleanup(struct vhost_dev *dev) int i; for (i = 0; i < dev->nvqs; ++i) { + /* No workers should run here by design. However, races have + * previously occurred where drivers have been unable to flush + * all work properly prior to clean-up. Without a successful + * flush the guest will malfunction, but avoiding host memory + * corruption in those cases does seem preferable. + */ + WARN_ON(mutex_is_locked(&dev->vqs[i]->mutex)); + + 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 +709,7 @@ 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) -- 2.35.1.616.g0bdcbb4464-goog _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization