From patchwork Mon Mar 1 16:12:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 390152 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 50493C433DB for ; Mon, 1 Mar 2021 16:50:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 180E065084 for ; Mon, 1 Mar 2021 16:50:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232055AbhCAQuJ (ORCPT ); Mon, 1 Mar 2021 11:50:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:46584 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235075AbhCAQnC (ORCPT ); Mon, 1 Mar 2021 11:43:02 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 90DB664EF2; Mon, 1 Mar 2021 16:29:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1614616176; bh=/opa7NkDfsggFxcZsiy5NCFhrJt9wStmMuH34R1yXeg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TR+pF8y4kXZzL/xGZk/TqxTpcE4BHXcAMhNXkAMX9i7MRtADNUgScmNOysw33CATu VuH6glygdKFCJXyCSIJAf1SstL6j63Upie/eyoXIY5sXdHlQzfe3yystslKnji4st1 8B389CnFBpAP4Q+Q/dW/TL23P1E/aptAlMx1vQ4s= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Juan Vazquez , "Andrea Parri (Microsoft)" , Michael Kelley , Wei Liu , Sasha Levin Subject: [PATCH 4.14 059/176] Drivers: hv: vmbus: Avoid use-after-free in vmbus_onoffer_rescind() Date: Mon, 1 Mar 2021 17:12:12 +0100 Message-Id: <20210301161023.880481531@linuxfoundation.org> X-Mailer: git-send-email 2.30.1 In-Reply-To: <20210301161020.931630716@linuxfoundation.org> References: <20210301161020.931630716@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Andrea Parri (Microsoft) [ Upstream commit e3fa4b747f085d2cda09bba0533b86fa76038635 ] When channel->device_obj is non-NULL, vmbus_onoffer_rescind() could invoke put_device(), that will eventually release the device and free the channel object (cf. vmbus_device_release()). However, a pointer to the object is dereferenced again later to load the primary_channel. The use-after-free can be avoided by noticing that this load/check is redundant if device_obj is non-NULL: primary_channel must be NULL if device_obj is non-NULL, cf. vmbus_add_channel_work(). Fixes: 54a66265d6754b ("Drivers: hv: vmbus: Fix rescind handling") Reported-by: Juan Vazquez Signed-off-by: Andrea Parri (Microsoft) Reviewed-by: Michael Kelley Link: https://lore.kernel.org/r/20201209070827.29335-5-parri.andrea@gmail.com Signed-off-by: Wei Liu Signed-off-by: Sasha Levin --- drivers/hv/channel_mgmt.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/hv/channel_mgmt.c b/drivers/hv/channel_mgmt.c index 5bf633c15cd4b..3891d3c2cc002 100644 --- a/drivers/hv/channel_mgmt.c +++ b/drivers/hv/channel_mgmt.c @@ -989,8 +989,7 @@ static void vmbus_onoffer_rescind(struct vmbus_channel_message_header *hdr) vmbus_device_unregister(channel->device_obj); put_device(dev); } - } - if (channel->primary_channel != NULL) { + } else if (channel->primary_channel != NULL) { /* * Sub-channel is being rescinded. Following is the channel * close sequence when initiated from the driveri (refer to