From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 C187130C160; Fri, 4 Sep 2026 06:04:17 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501858; cv=none; b=kMuZQGRJm3i9RMFE2JP6XH4Km58P5sJHp8b0Xn06plE7NWk4V3yBeOgoxKzj9b2eP7LVUsXh6whsWjzkF82U0WQFLq1+5jwAsd0jdehuYOrzQZgH4szzJLzQQZiO81W51rCFthzS/ubJ9P2qcHHCLG70KkV6zPp3Tm6fQL0f1x0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788501858; c=relaxed/simple; bh=4CkTj/292wQu3hP+W8UQcn7zS6ZpNc5euFPQumjyO5s=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ryeRzscIoPzuD6IuKUIyYfOFfb6K4x9NTaOb1lasHmbqagp5AOGdmeN7Hiwo/pYMPnsq8saWTmOi1dGkPGwjqPLFVYg3sket93K++pHilVqVOQ+YK/0lZVwAto6s1GLk1K008KXTdiiZqCBU1/RNX/77aCl0b/geoj8n8Ap1uhc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=nZEkkTOU; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="nZEkkTOU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2555C1F00A3D; Fri, 4 Sep 2026 06:04:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1788501857; bh=hoaRDOA7Dn5dQpntoiT0WBSIligNr6JUBftkM6uHbhM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nZEkkTOUIvisvp9HQ2Ti8Bz3+3vuusk+25FBxa2+KHnvI93xAgKuYMhYJu9XpKuqC zD43f2Lj6wxP+aLkZ5FVitxaECnrgcvl2EgmsjCmFN/fQAYLPGGQpSX4dOdb+ai+fX AT9e1XpEPu5+ZJx4FI2Jg5iYLkzuMCTD9+wFjAmo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Chengfeng Ye , Paolo Abeni Subject: [PATCH 6.18 538/552] vsock/virtio: flush works in dependency order Date: Fri, 4 Sep 2026 07:01:35 +0200 Message-ID: <20260904045802.811128166@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260904045747.813364717@linuxfoundation.org> References: <20260904045747.813364717@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Chengfeng Ye commit 728836ebca239810f164262b10211ef59182f811 upstream. virtio_vsock_remove() stops the virtqueues and then flushes each work item before freeing the enclosing virtio_vsock. The current order does not account for dependencies between those items: tx_work may queue send_pkt_work, and send_pkt_work may queue rx_work. In particular, send_pkt_work can set restart_rx and release tx_lock. The remove path can then stop the queues and flush rx_work before send_pkt_work queues it. Although the later send_pkt_work flush waits for that producer to finish, nothing waits for the newly queued rx_work, so kfree(vsock) can race with it. KASAN reported: BUG: KASAN: slab-use-after-free in virtio_transport_rx_work+0x487/0x4b0 Read of size 8 at addr ffff888114c2b008 by task kworker/1:1/47 Workqueue: virtio_vsock virtio_transport_rx_work Call Trace: virtio_transport_rx_work+0x487/0x4b0 process_one_work+0x688/0x1120 worker_thread+0x45b/0xd10 Allocated by task 1: virtio_vsock_probe+0xef/0x6b0 Freed by task 84: kfree+0x131/0x3c0 virtio_vsock_remove+0xd1/0x100 Flush the works in producer-to-consumer order. virtio_vsock_vqs_del() has already disabled the queue callbacks and cleared the run flags, so after tx_work and send_pkt_work are drained, no source remains that can queue rx_work after its flush. Fixes: 0ea9e1d3a9e3 ("VSOCK: Introduce virtio_transport.ko") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye Link: https://patch.msgid.link/20260822164556.3750959-1-nicoyip.dev@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman --- net/vmw_vsock/virtio_transport.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -848,10 +848,10 @@ static void virtio_vsock_remove(struct v /* Other works can be queued before 'config->del_vqs()', so we flush * all works before to free the vsock object to avoid use after free. */ - flush_work(&vsock->rx_work); flush_work(&vsock->tx_work); flush_work(&vsock->event_work); flush_work(&vsock->send_pkt_work); + flush_work(&vsock->rx_work); mutex_unlock(&the_virtio_vsock_mutex);