From patchwork Thu Aug 27 09:58:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Wagner X-Patchwork-Id: 11740497 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id CED0B913 for ; Thu, 27 Aug 2020 09:58:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BFD012087C for ; Thu, 27 Aug 2020 09:58:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728501AbgH0J6d (ORCPT ); Thu, 27 Aug 2020 05:58:33 -0400 Received: from mx2.suse.de ([195.135.220.15]:37234 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728386AbgH0J6d (ORCPT ); Thu, 27 Aug 2020 05:58:33 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 20731AD79; Thu, 27 Aug 2020 09:59:03 +0000 (UTC) From: Daniel Wagner To: linux-scsi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nilesh Javali , Daniel Wagner Subject: [PATCH 1/4] qla2xxx: Reset done and free callback pointer on release Date: Thu, 27 Aug 2020 11:58:26 +0200 Message-Id: <20200827095829.63871-2-dwagner@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200827095829.63871-1-dwagner@suse.de> References: <20200827095829.63871-1-dwagner@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Reset ->done and ->free when releasing the srb. There is a hidden use-after-free bug in the driver which corrupts the srb memory pool which originates from the cleanup callbacks. By explicitly resetting the callbacks to NULL, we workaround the memory corruption. An extensive search didn't bring any lights on the real problem. The initial idea was to set both pointers to NULL and try to catch invalid accesses. But instead the memory corruption was gone and the driver didn't crash. Signed-off-by: Daniel Wagner --- drivers/scsi/qla2xxx/qla_inline.h | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h index 861dc522723c..6d41d758fc17 100644 --- a/drivers/scsi/qla2xxx/qla_inline.h +++ b/drivers/scsi/qla2xxx/qla_inline.h @@ -211,6 +211,8 @@ static inline void qla2xxx_rel_qpair_sp(struct qla_qpair *qpair, srb_t *sp) { sp->qpair = NULL; + sp->done = NULL; + sp->free = NULL; mempool_free(sp, qpair->srb_mempool); QLA_QPAIR_MARK_NOT_BUSY(qpair); }