From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755050Ab2LMKsD (ORCPT ); Thu, 13 Dec 2012 05:48:03 -0500 Received: from smtp.eu.citrix.com ([46.33.159.39]:53306 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754737Ab2LMKsA (ORCPT ); Thu, 13 Dec 2012 05:48:00 -0500 X-IronPort-AV: E=Sophos;i="4.84,273,1355097600"; d="scan'208";a="110293" From: Roger Pau Monne To: CC: Roger Pau Monne , Konrad Rzeszutek Wilk , Subject: [PATCH v4 3/3] xen-blkfront: transverse list of persistent grants safely Date: Thu, 13 Dec 2012 11:39:39 +0100 Message-ID: <1355395179-55724-3-git-send-email-roger.pau@citrix.com> X-Mailer: git-send-email 1.7.7.5 (Apple Git-26) In-Reply-To: <1355395179-55724-1-git-send-email-roger.pau@citrix.com> References: <1355395179-55724-1-git-send-email-roger.pau@citrix.com> MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Use llist_for_each_entry_safe in blkif_free. Previously grants where freed while iterating the list, which lead to dereferences when trying to fetch the next item. Reported-by: Dan Carpenter Signed-off-by: Roger Pau Monné Cc: Konrad Rzeszutek Wilk Cc: xen-devel@lists.xen.org --- drivers/block/xen-blkfront.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c index 96e9b00..8ae8062 100644 --- a/drivers/block/xen-blkfront.c +++ b/drivers/block/xen-blkfront.c @@ -791,7 +791,7 @@ static void blkif_restart_queue(struct work_struct *work) static void blkif_free(struct blkfront_info *info, int suspend) { struct llist_node *all_gnts; - struct grant *persistent_gnt; + struct grant *persistent_gnt, *n; /* Prevent new requests being issued until we fix things up. */ spin_lock_irq(&info->io_lock); @@ -804,7 +804,7 @@ static void blkif_free(struct blkfront_info *info, int suspend) /* Remove all persistent grants */ if (info->persistent_gnts_c) { all_gnts = llist_del_all(&info->persistent_gnts); - llist_for_each_entry(persistent_gnt, all_gnts, node) { + llist_for_each_entry_safe(persistent_gnt, n, all_gnts, node) { gnttab_end_foreign_access(persistent_gnt->gref, 0, 0UL); __free_page(pfn_to_page(persistent_gnt->pfn)); kfree(persistent_gnt); -- 1.7.7.5 (Apple Git-26)