Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752046AbdGPODM (ORCPT ); Sun, 16 Jul 2017 10:03:12 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:43318 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751864AbdGPN6E (ORCPT ); Sun, 16 Jul 2017 09:58:04 -0400 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Rafael J. Wysocki" , "James Morse" , "Huang, Ying" Date: Sun, 16 Jul 2017 14:56:46 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 097/178] ACPI / APEI: Add missing synchronize_rcu() on NOTIFY_SCI removal In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:6f00:88c8:c921:d332 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1162 Lines: 32 3.16.46-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: James Morse commit 7d64f82cceb21e6d95db312d284f5f195e120154 upstream. When removing a GHES device notified by SCI, list_del_rcu() is used, ghes_remove() should call synchronize_rcu() before it goes on to call kfree(ghes), otherwise concurrent RCU readers may still hold this list entry after it has been freed. Signed-off-by: James Morse Reviewed-by: "Huang, Ying" Fixes: 81e88fdc432a (ACPI, APEI, Generic Hardware Error Source POLL/IRQ/NMI notification type support) Signed-off-by: Rafael J. Wysocki Signed-off-by: Ben Hutchings --- drivers/acpi/apei/ghes.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/acpi/apei/ghes.c +++ b/drivers/acpi/apei/ghes.c @@ -1020,6 +1020,7 @@ static int ghes_remove(struct platform_d if (list_empty(&ghes_sci)) unregister_acpi_hed_notifier(&ghes_notifier_sci); mutex_unlock(&ghes_list_mutex); + synchronize_rcu(); break; case ACPI_HEST_NOTIFY_NMI: mutex_lock(&ghes_list_mutex);