From patchwork Thu Jul 25 08:54:21 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mathias Nyman X-Patchwork-Id: 11058271 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id E282C13A4 for ; Thu, 25 Jul 2019 08:53:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id D20E2287A6 for ; Thu, 25 Jul 2019 08:53:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id C502128952; Thu, 25 Jul 2019 08:53:13 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 40A31287A6 for ; Thu, 25 Jul 2019 08:53:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389872AbfGYIxL (ORCPT ); Thu, 25 Jul 2019 04:53:11 -0400 Received: from mga01.intel.com ([192.55.52.88]:22618 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388889AbfGYIxL (ORCPT ); Thu, 25 Jul 2019 04:53:11 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga001.jf.intel.com ([10.7.209.18]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 25 Jul 2019 01:53:10 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.64,306,1559545200"; d="scan'208";a="253871913" Received: from mattu-haswell.fi.intel.com ([10.237.72.164]) by orsmga001.jf.intel.com with ESMTP; 25 Jul 2019 01:53:08 -0700 From: Mathias Nyman To: Cc: , Mathias Nyman , "# v5 . 2" , Nicolas Saenz Julienne Subject: [PATCH] xhci: Fix crash if scatter gather is used with Immediate Data Transfer (IDT). Date: Thu, 25 Jul 2019 11:54:21 +0300 Message-Id: <1564044861-1445-1-git-send-email-mathias.nyman@linux.intel.com> X-Mailer: git-send-email 2.7.4 Sender: linux-usb-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP A second regression was found in the immediate data transfer (IDT) support which was added to 5.2 kernel IDT is used to transfer small amounts of data (up to 8 bytes) in the field normally used for data dma address, thus avoiding dma mapping. If the data was not already dma mapped, then IDT support assumed data was in urb->transfer_buffer, and did not take into accound that even small amounts of data (8 bytes) can be in a scatterlist instead. This caused a NULL pointer dereference when sg_dma_len() was used with non-dma mapped data. Solve this by not using IDT if scatter gather buffer list is used. Fixes: 33e39350ebd2 ("usb: xhci: add Immediate Data Transfer support") Cc: # v5.2 Reported-by: Maik Stohn Tested-by: Maik Stohn CC: Nicolas Saenz Julienne Signed-off-by: Mathias Nyman --- drivers/usb/host/xhci.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/usb/host/xhci.h b/drivers/usb/host/xhci.h index 7a26496..f5c4144 100644 --- a/drivers/usb/host/xhci.h +++ b/drivers/usb/host/xhci.h @@ -2175,7 +2175,8 @@ static inline bool xhci_urb_suitable_for_idt(struct urb *urb) if (!usb_endpoint_xfer_isoc(&urb->ep->desc) && usb_urb_dir_out(urb) && usb_endpoint_maxp(&urb->ep->desc) >= TRB_IDT_MAX_SIZE && urb->transfer_buffer_length <= TRB_IDT_MAX_SIZE && - !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) + !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP) && + !urb->num_sgs) return true; return false;