From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (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 766FB486B95 for ; Wed, 29 Jul 2026 14:44:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785336277; cv=none; b=YIYf+nQOpZOWf8M9DiYJdAMVuC5vCO/8rfmmBsvdBEWApeyaZrkHTx4+yk/smtnrV82nBPrB3eHKOHnyZRG8Td4O8i/fAr90rEVufeyNd+hE4zQavItrnH/axDgqUhkXjUNHmEqLH/RWL3z/Vfeuun7rRGbUhoGftbUEejcgMcY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785336277; c=relaxed/simple; bh=BJS1HA8rokFIiV0ne5cRaLj+3cbfWQFKkW4X/b+NT0U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=QzlcIixhJmEfvVBSAeS8IHBLURSDuJjvC5/pnVSZOMlrKxSRCEMFtrqmUSY/aulSkWvhXWElgh3rUIKdIes7037i7eXJdyD8gU2Va0GpAqdiJ1/scxEJFcWNdzoLXYYQfITJxW37EFuDsZmDR9ooPPE3RetI3oqUqFKcPlmxQKI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=YNWcPWPn; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=LdpwD0qW; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YNWcPWPn"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="LdpwD0qW" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1785336274; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5H5BXZFmwChe72ax9v3fx7rbm4FIcGAxuXQx1+sJiZI=; b=YNWcPWPn9bvAPNDTNyD2ILT5WLEI7d/1jOq4dpgpaLzenlwxMGF/XU2WLVa/vLq1u6VZKJ g+ZOI/W2pWL6E13TVrj9aatcGZ3t2u3miOaCvVp26h4zpIWMhRQCJrx2qQ02AyOdegEs7j C/6E8lnswo7449EYUtRc1NypluOrXHU= Received: from mail-wm1-f72.google.com (mail-wm1-f72.google.com [209.85.128.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-281-X3iwhGeRPGW06ZH0GHPewQ-1; Wed, 29 Jul 2026 10:44:33 -0400 X-MC-Unique: X3iwhGeRPGW06ZH0GHPewQ-1 X-Mimecast-MFC-AGG-ID: X3iwhGeRPGW06ZH0GHPewQ_1785336272 Received: by mail-wm1-f72.google.com with SMTP id 5b1f17b1804b1-4955d314945so7428235e9.0 for ; Wed, 29 Jul 2026 07:44:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1785336272; x=1785941072; darn=vger.kernel.org; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=5H5BXZFmwChe72ax9v3fx7rbm4FIcGAxuXQx1+sJiZI=; b=LdpwD0qWphlkCEBxQYrOyS6FkvxzQKoLILQlGrnVFFL763mILU1nefBW7SlHcpU+F6 PjsWBFtIiA5eajvFseDlOKCMEAcaW5LJFbXiUOBs74aiww/s+Z87klLkY/Y+rhzwSR8k r37Lha8dRLpCV3ekeHsespKsfqWahPFrN2YlbPI7ad38HSW684mQYfpFwdyhNZcI8ra+ uGqzah5sS2rSy9osSn3Gx5X54MNQCKUqy6sM6s7R2OU340BUNGqWlJeiKkdZOPY+F/MX 2lpxXmvTyYOGArBoPERg7O/d40hNo1FtNK6OpUs4P7806N6wrqoMsJIsyTA64/53k5Kk EVzA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1785336272; x=1785941072; h=in-reply-to:content-disposition:content-type:mime-version :references:message-id:subject:cc:to:from:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=5H5BXZFmwChe72ax9v3fx7rbm4FIcGAxuXQx1+sJiZI=; b=klsl9qn89xEdXMmJ01K/vmkFyTcNmj2TQAyLc9DDJiOE5C8z/7yzAtyZWZLivflSYZ pZCFVKtUqcK/M6CrJwcypvpHieARAQMqiE7D1TxP6w8UT4v0MhM4EcZUP4wwbjg65QoJ hlwlYwlMjymKnZPRj9XC6g63RG+GGk0g14T85BrvAMrnbl72GI5Jna8mGjFwNhO/KgZn 17+bz3hlIhVeKDq0CFUTBhRkvMUZeehVAmDxskFywX4ld5Iv4YZS9XBh/eGUBE2iMQCJ db/crfQ7NKHLbZBQwCkArVVb6+CyeCYeTQXIsxGFiKnqivA/xu7XVUDIzdapKHFGXCJc KR0A== X-Forwarded-Encrypted: i=1; AHgh+RokQl43fRSZo7mZiaTEluTGg4ibFhhmS7NyCO+JbRxzWXN+s1BK1JxyYVntJ8+Y6vGlco/kkz3Z6sW4aNQ=@vger.kernel.org X-Gm-Message-State: AOJu0Yxi4zAbCZ+wOZg6Qm0OBdd6BZ9JYqdCB0bIpRH/avNbekMGBQ7p ImrLk+pC48mZeaUdxzymjTrOv4l/OITu0UMqsAx0+x7n7kWOU7nkmV5JjScRqwx24nibdAk140P FpAe/1CCy0FneG7KuCFhoWhJOfjYUrwrbXAHtKnvXC8rZ7DIjhhVjj+SaRYhX4BOI5g== X-Gm-Gg: AR+sD10lROV1WWwNi7htRch1WJWjmIBhZrgzrCiB5mrJGR+TSf4yJksS8jEJ/hoOAZT y0nOf+2UJ9IjlTrk9kvN2dt7pdavAn/fq7J3JdDHWXUUIPgT8gdNWAqR+MX07zAThrI2JBPg9KP 8Y1WHW++rGTYb4BrJLFURTIm6gADsfZFg2YKbqZo75KdsB+Bzide9MFJhYBPT05+APnbj+3QDoK FpUaGT+TcRrl4/MZEL8WJQ0p22kQMVotzXWkRSw1sMxJLVeRC+dp6V6Kb0zWT9SGsO2z+aGs8HA 2HIBSBaTE+YFlnW9H/quCpqrvYnwbnnPKtMNlpSrJiTYl8dexJrX0shHo+rtZkiOQM4EoXz9c7u cqprABnuE2ia1QYAGLiOYPdlubVwo5ADR47FxDl+2Quk= X-Received: by 2002:a05:600c:c162:b0:495:7285:a498 with SMTP id 5b1f17b1804b1-496c656540fmr82603465e9.18.1785336271618; Wed, 29 Jul 2026 07:44:31 -0700 (PDT) X-Received: by 2002:a05:600c:c162:b0:495:7285:a498 with SMTP id 5b1f17b1804b1-496c656540fmr82603015e9.18.1785336271121; Wed, 29 Jul 2026 07:44:31 -0700 (PDT) Received: from sgarzare-redhat (ip139-137-192-82.pool-bba.aruba.it. [82.192.137.139]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-4976bd52f3fsm36693245e9.0.2026.07.29.07.44.29 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 29 Jul 2026 07:44:30 -0700 (PDT) Date: Wed, 29 Jul 2026 16:44:23 +0200 From: Stefano Garzarella To: Weiming Shi Cc: "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , Eugenio =?utf-8?B?UMOpcmV6?= , Stefan Hajnoczi , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , virtualization@lists.linux.dev, kvm@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Xiang Mei , stable@vger.kernel.org Subject: Re: [PATCH] vsock/virtio: prevent workers from using deleted virtqueues Message-ID: References: <20260727035804.1860862-1-bestswngs@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20260727035804.1860862-1-bestswngs@gmail.com> On Sun, Jul 26, 2026 at 08:58:01PM -0700, Weiming Shi wrote: >The RX, TX and event workers read their virtqueue pointers before taking >the mutex that protects the queue and its run flag. A work item delayed >across freeze and restore can therefore retain a pointer deleted by >virtio_vsock_vqs_del(), observe the run flag for the replacement queues, >and use the freed pointer. > >RX has an additional path: when rx_run is clear, the common exit still >refills the RX queue. A queued worker can consequently call >virtqueue_add_sgs() immediately after freeze deletes the virtqueues. > >BUG: KASAN: slab-use-after-free in virtqueue_add_sgs >Read of size 4 by task kworker/2:1 >Workqueue: virtio_vsock virtio_transport_rx_work >Call Trace: > virtqueue_add_sgs (drivers/virtio/virtio_ring.c:2796) > virtio_vsock_rx_fill (net/vmw_vsock/virtio_transport.c:332) > virtio_transport_rx_work (net/vmw_vsock/virtio_transport.c:701) > process_one_work (kernel/workqueue.c:3314) > worker_thread (kernel/workqueue.c:3478) > kthread (kernel/kthread.c:436) > ret_from_fork (arch/x86/kernel/process.c:158) > ret_from_fork_asm (arch/x86/entry/entry_64.S:245) >... >Freed by task 141: > kfree (mm/slub.c:6566) > vp_del_vq (drivers/virtio/virtio_pci_common.c:259) > vp_del_vqs (drivers/virtio/virtio_pci_common.c:285) > virtio_vsock_freeze (net/vmw_vsock/virtio_transport.c:912) > virtio_device_freeze (drivers/virtio/virtio.c:658) > virtio_pci_freeze (drivers/virtio/virtio_pci_common.c:601) > pci_pm_freeze (drivers/pci/pci-driver.c:1098) > device_suspend (drivers/base/power/main.c:1968) >Kernel panic - not syncing: KASAN: panic_on_warn set ... > >Read each worker's virtqueue under its mutex after confirming that the >queue is running, and only refill RX while RX is running. > >Fixes: b917507e5ad9 ("vsock/virtio: stop workers during the .remove()") >Cc: stable@vger.kernel.org >Reported-by: Xiang Mei >Assisted-by: OpenAI-Codex:gpt-5 >Signed-off-by: Weiming Shi >--- > net/vmw_vsock/virtio_transport.c | 14 ++++++++------ > 1 file changed, 8 insertions(+), 6 deletions(-) > >diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c >index 57f2d6ec3ffc..79cf19f58943 100644 >--- a/net/vmw_vsock/virtio_transport.c >+++ b/net/vmw_vsock/virtio_transport.c >@@ -346,12 +346,13 @@ static void virtio_transport_tx_work(struct work_struct *work) > struct virtqueue *vq; > bool added = false; > >- vq = vsock->vqs[VSOCK_VQ_TX]; > mutex_lock(&vsock->tx_lock); > > if (!vsock->tx_run) > goto out; > >+ vq = vsock->vqs[VSOCK_VQ_TX]; >+ > do { > struct sk_buff *skb; > unsigned int len; >@@ -451,13 +452,13 @@ static void virtio_transport_event_work(struct work_struct *work) > container_of(work, struct virtio_vsock, event_work); > struct virtqueue *vq; > >- vq = vsock->vqs[VSOCK_VQ_EVENT]; >- > mutex_lock(&vsock->event_lock); > > if (!vsock->event_run) > goto out; > >+ vq = vsock->vqs[VSOCK_VQ_EVENT]; >+ > do { > struct virtio_vsock_event *event; > unsigned int len; >@@ -634,13 +635,13 @@ static void virtio_transport_rx_work(struct work_struct *work) > container_of(work, struct virtio_vsock, rx_work); > struct virtqueue *vq; > >- vq = vsock->vqs[VSOCK_VQ_RX]; >- > mutex_lock(&vsock->rx_lock); > > if (!vsock->rx_run) > goto out; > >+ vq = vsock->vqs[VSOCK_VQ_RX]; >+ > do { > virtqueue_disable_cb(vq); > for (;;) { >@@ -689,7 +690,8 @@ static void virtio_transport_rx_work(struct work_struct *work) > } while (!virtqueue_enable_cb(vq)); > > out: >- if (vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) >+ if (vsock->rx_run && Instead of adding this check, what about adding a new label... >+ vsock->rx_buf_nr < vsock->rx_buf_max_nr / 2) > virtio_vsock_rx_fill(vsock); out_nofill: > mutex_unlock(&vsock->rx_lock); And use it when we check `vsock->rx_run` ? Since we are taking the mutex, we don't need to check it again. The rest LGTM, but I agree with Bobby about the split, since the Fixes tag here is confusing. I'll reply there. Thanks, Stefano