From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Borislav Petkov , Thomas Gleixner Subject: [PATCH 4.4 096/103] genirq: Fix chained interrupt data ordering Date: Tue, 23 May 2017 22:10:02 +0200 Message-Id: <20170523200904.310997355@linuxfoundation.org> In-Reply-To: <20170523200856.903752266@linuxfoundation.org> References: <20170523200856.903752266@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Gleixner commit 2c4569ca26986d18243f282dd727da27e9adae4c upstream. irq_set_chained_handler_and_data() sets up the chained interrupt and then stores the handler data. That's racy against an immediate interrupt which gets handled before the store of the handler data happened. The handler will dereference a NULL pointer and crash. Cure it by storing handler data before installing the chained handler. Reported-by: Borislav Petkov Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman --- kernel/irq/chip.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/kernel/irq/chip.c +++ b/kernel/irq/chip.c @@ -810,8 +810,8 @@ irq_set_chained_handler_and_data(unsigne if (!desc) return; - __irq_do_set_handler(desc, handle, 1, NULL); desc->irq_common_data.handler_data = data; + __irq_do_set_handler(desc, handle, 1, NULL); irq_put_desc_busunlock(desc, flags); }