From patchwork Mon Aug 31 16:18:51 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Wagner X-Patchwork-Id: 11746651 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 EC8B1138A for ; Mon, 31 Aug 2020 16:19:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DB0BC208DB for ; Mon, 31 Aug 2020 16:19:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728625AbgHaQTY (ORCPT ); Mon, 31 Aug 2020 12:19:24 -0400 Received: from mx2.suse.de ([195.135.220.15]:45884 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728394AbgHaQTW (ORCPT ); Mon, 31 Aug 2020 12:19:22 -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 8234DAC6F; Mon, 31 Aug 2020 16:19:19 +0000 (UTC) From: Daniel Wagner To: linux-scsi@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Nilesh Javali , Martin Wilck , Daniel Wagner Subject: [PATCH v2 1/4] qla2xxx: Warn if done() or free() are called on an already freed srb Date: Mon, 31 Aug 2020 18:18:51 +0200 Message-Id: <20200831161854.70879-2-dwagner@suse.de> X-Mailer: git-send-email 2.16.4 In-Reply-To: <20200831161854.70879-1-dwagner@suse.de> References: <20200831161854.70879-1-dwagner@suse.de> Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Emit a warning when ->done or ->free are called on an already freed 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_init.c | 10 ++++++++++ drivers/scsi/qla2xxx/qla_inline.h | 5 +++++ 2 files changed, 15 insertions(+) diff --git a/drivers/scsi/qla2xxx/qla_init.c b/drivers/scsi/qla2xxx/qla_init.c index 57a2d76aa691..9e9360a4aeb5 100644 --- a/drivers/scsi/qla2xxx/qla_init.c +++ b/drivers/scsi/qla2xxx/qla_init.c @@ -63,6 +63,16 @@ void qla2x00_sp_free(srb_t *sp) qla2x00_rel_sp(sp); } +void qla2xxx_rel_done_warning(srb_t *sp, int res) +{ + WARN_ONCE(1, "Calling done() of an already freed srb object\n"); +} + +void qla2xxx_rel_free_warning(srb_t *sp) +{ + WARN_ONCE(1, "Calling free() of an already freed srb object\n"); +} + /* Asynchronous Login/Logout Routines -------------------------------------- */ unsigned long diff --git a/drivers/scsi/qla2xxx/qla_inline.h b/drivers/scsi/qla2xxx/qla_inline.h index 861dc522723c..2aa6f81f87c4 100644 --- a/drivers/scsi/qla2xxx/qla_inline.h +++ b/drivers/scsi/qla2xxx/qla_inline.h @@ -207,10 +207,15 @@ qla2xxx_get_qpair_sp(scsi_qla_host_t *vha, struct qla_qpair *qpair, return sp; } +void qla2xxx_rel_done_warning(srb_t *sp, int res); +void qla2xxx_rel_free_warning(srb_t *sp); + static inline void qla2xxx_rel_qpair_sp(struct qla_qpair *qpair, srb_t *sp) { sp->qpair = NULL; + sp->done = qla2xxx_rel_done_warning; + sp->free = qla2xxx_rel_free_warning; mempool_free(sp, qpair->srb_mempool); QLA_QPAIR_MARK_NOT_BUSY(qpair); }