From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S942405AbcJFIn7 (ORCPT ); Thu, 6 Oct 2016 04:43:59 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47403 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S941953AbcJFIn4 (ORCPT ); Thu, 6 Oct 2016 04:43:56 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Andrew Donnellan , Michael Ellerman Subject: [PATCH 4.7 100/141] cxl: fix potential NULL dereference in free_adapter() Date: Thu, 6 Oct 2016 10:28:56 +0200 Message-Id: <20161006074453.013989948@linuxfoundation.org> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161006074448.608056610@linuxfoundation.org> References: <20161006074448.608056610@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.7-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrew Donnellan commit 8fbaa51d43ef2c6a72849ec34060910723a0365f upstream. If kzalloc() fails when allocating adapter->guest in cxl_guest_init_adapter(), we call free_adapter() before erroring out. free_adapter() in turn attempts to dereference adapter->guest, which in this case is NULL. In free_adapter(), skip the adapter->guest cleanup if adapter->guest is NULL. Fixes: 14baf4d9c739 ("cxl: Add guest-specific code") Reported-by: Dan Carpenter Signed-off-by: Andrew Donnellan Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- drivers/misc/cxl/guest.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/drivers/misc/cxl/guest.c +++ b/drivers/misc/cxl/guest.c @@ -1052,16 +1052,18 @@ static void free_adapter(struct cxl *ada struct irq_avail *cur; int i; - if (adapter->guest->irq_avail) { - for (i = 0; i < adapter->guest->irq_nranges; i++) { - cur = &adapter->guest->irq_avail[i]; - kfree(cur->bitmap); + if (adapter->guest) { + if (adapter->guest->irq_avail) { + for (i = 0; i < adapter->guest->irq_nranges; i++) { + cur = &adapter->guest->irq_avail[i]; + kfree(cur->bitmap); + } + kfree(adapter->guest->irq_avail); } - kfree(adapter->guest->irq_avail); + kfree(adapter->guest->status); + kfree(adapter->guest); } - kfree(adapter->guest->status); cxl_remove_adapter_nr(adapter); - kfree(adapter->guest); kfree(adapter); }