From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Matthew R. Ochs" Subject: [PATCH v6 20/37] cxlflash: Fix to prevent workq from accessing freed memory Date: Wed, 21 Oct 2015 15:14:17 -0500 Message-ID: <1445458457-31539-1-git-send-email-mrochs@linux.vnet.ibm.com> References: <1445458134-63197-1-git-send-email-mrochs@linux.vnet.ibm.com> Return-path: Received: from e31.co.us.ibm.com ([32.97.110.149]:39501 "EHLO e31.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932530AbbJUUPk (ORCPT ); Wed, 21 Oct 2015 16:15:40 -0400 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 21 Oct 2015 14:15:39 -0600 Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 6E4A019D804A for ; Wed, 21 Oct 2015 14:03:46 -0600 (MDT) Received: from d03av05.boulder.ibm.com (d03av05.boulder.ibm.com [9.17.195.85]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t9LKEG5F5636512 for ; Wed, 21 Oct 2015 13:14:16 -0700 Received: from d03av05.boulder.ibm.com (localhost [127.0.0.1]) by d03av05.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t9LKFYT2026283 for ; Wed, 21 Oct 2015 14:15:35 -0600 In-Reply-To: <1445458134-63197-1-git-send-email-mrochs@linux.vnet.ibm.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi@vger.kernel.org, James Bottomley , "Nicholas A. Bellinger" , Brian King , Ian Munsie , Daniel Axtens , Andrew Donnellan , Tomas Henzl , David Laight Cc: Michael Neuling , "Manoj N. Kumar" , linuxppc-dev@lists.ozlabs.org The workq can process work in parallel with a remove event, leading to a condition where the workq handler can access freed memory. To remedy, the workq should be terminated prior to freeing memory. Move the termination call earlier in remove and use cancel_work_sync() instead of flush_work() as there is not a need to process any scheduled work when shutting down. Signed-off-by: Matthew R. Ochs Signed-off-by: Manoj N. Kumar Reviewed-by: Brian King --- drivers/scsi/cxlflash/main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c index 6b8b159..d0b9972 100644 --- a/drivers/scsi/cxlflash/main.c +++ b/drivers/scsi/cxlflash/main.c @@ -736,11 +736,11 @@ static void cxlflash_remove(struct pci_dev *pdev) /* Fall through */ case INIT_STATE_AFU: term_afu(cfg); + cancel_work_sync(&cfg->work_q); case INIT_STATE_PCI: pci_release_regions(cfg->dev); pci_disable_device(pdev); case INIT_STATE_NONE: - flush_work(&cfg->work_q); free_mem(cfg); scsi_host_put(cfg->host); break; -- 2.1.0