Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932607AbbFIDwG (ORCPT ); Mon, 8 Jun 2015 23:52:06 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:29089 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932385AbbFIDvo (ORCPT ); Mon, 8 Jun 2015 23:51:44 -0400 From: Calvin Owens To: Nagalakshmi Nandigama , Praveen Krishnamoorthy , Sreekanth Reddy , Abhijit Mahajan CC: , , , , Subject: [PATCH 6/6] Fix unsafe fw_event_list usage Date: Mon, 8 Jun 2015 20:50:56 -0700 Message-ID: <1433821856-2815280-7-git-send-email-calvinowens@fb.com> X-Mailer: git-send-email 1.8.1 In-Reply-To: <1433821856-2815280-1-git-send-email-calvinowens@fb.com> References: <1431661322-3097935-1-git-send-email-calvinowens@fb.com> <1433821856-2815280-1-git-send-email-calvinowens@fb.com> MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [192.168.52.123] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-06-09_04:2015-06-08,2015-06-09,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2187 Lines: 68 Since the fw_event deletes itself from the list, cleanup_queue() can walk onto garbage pointers or walk off into freed memory. This refactors the code in _scsih_fw_event_cleanup_queue() to not iterate over the fw_event_list without a lock. Signed-off-by: Calvin Owens --- drivers/scsi/mpt2sas/mpt2sas_scsih.c | 22 ++++++++++++++++++++-- 1 file changed, 20 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/mpt2sas/mpt2sas_scsih.c b/drivers/scsi/mpt2sas/mpt2sas_scsih.c index 8d8c814..f504e28 100644 --- a/drivers/scsi/mpt2sas/mpt2sas_scsih.c +++ b/drivers/scsi/mpt2sas/mpt2sas_scsih.c @@ -2939,6 +2939,23 @@ mpt2sas_port_enable_complete(struct MPT2SAS_ADAPTER *ioc) fw_event_work_put(fw_event); } +static struct fw_event_work *dequeue_next_fw_event(struct MPT2SAS_ADAPTER *ioc) +{ + unsigned long flags; + struct fw_event_work *fw_event = NULL; + + spin_lock_irqsave(&ioc->fw_event_lock, flags); + if (!list_empty(&ioc->fw_event_list)) { + fw_event = list_first_entry(&ioc->fw_event_list, + struct fw_event_work, list); + list_del_init(&fw_event->list); + fw_event_work_get(fw_event); + } + spin_unlock_irqrestore(&ioc->fw_event_lock, flags); + + return fw_event; +} + /** * _scsih_fw_event_cleanup_queue - cleanup event queue * @ioc: per adapter object @@ -2951,17 +2968,18 @@ mpt2sas_port_enable_complete(struct MPT2SAS_ADAPTER *ioc) static void _scsih_fw_event_cleanup_queue(struct MPT2SAS_ADAPTER *ioc) { - struct fw_event_work *fw_event, *next; + struct fw_event_work *fw_event; if (list_empty(&ioc->fw_event_list) || !ioc->firmware_event_thread || in_interrupt()) return; - list_for_each_entry_safe(fw_event, next, &ioc->fw_event_list, list) { + while ((fw_event = dequeue_next_fw_event(ioc))) { if (cancel_delayed_work_sync(&fw_event->delayed_work)) { _scsih_fw_event_free(ioc, fw_event); continue; } + fw_event_work_put(fw_event); } } -- 1.8.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/