From patchwork Wed Jul 20 13:34:16 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Marc Kleine-Budde X-Patchwork-Id: 12923995 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 754EEC433EF for ; Wed, 20 Jul 2022 13:34:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231668AbiGTNeX (ORCPT ); Wed, 20 Jul 2022 09:34:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59048 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229829AbiGTNeW (ORCPT ); Wed, 20 Jul 2022 09:34:22 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3ED57387 for ; Wed, 20 Jul 2022 06:34:21 -0700 (PDT) Received: from gallifrey.ext.pengutronix.de ([2001:67c:670:201:5054:ff:fe8d:eefb] helo=bjornoya.blackshift.org) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1oE9qF-0004tj-Bg for linux-spi@vger.kernel.org; Wed, 20 Jul 2022 15:34:19 +0200 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id B6048B5EAF for ; Wed, 20 Jul 2022 13:34:18 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 57267B5EAA; Wed, 20 Jul 2022 13:34:18 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 911f8268; Wed, 20 Jul 2022 13:34:17 +0000 (UTC) From: Marc Kleine-Budde To: linux-spi@vger.kernel.org Cc: kernel@pengutronix.de, Marc Kleine-Budde , Lukas Wunner , Mark Brown , Jens Lindahl Subject: [PATCH v2] spi: bcm2835: bcm2835_spi_handle_err(): fix NULL pointer deref for non DMA transfers Date: Wed, 20 Jul 2022 15:34:16 +0200 Message-Id: <20220720133416.3342229-1-mkl@pengutronix.de> X-Mailer: git-send-email 2.35.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:201:5054:ff:fe8d:eefb X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-spi@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-spi@vger.kernel.org In case a IRQ based transfer times out the bcm2835_spi_handle_err() function is called. Since commit 1513ceee70f2 ("spi: bcm2835: Drop dma_pending flag") the TX and RX DMA transfers are unconditionally canceled, leading to NULL pointer derefs if ctlr->dma_tx or ctlr->dma_rx are not set. Fix the NULL pointer deref by checking that ctlr->dma_tx and ctlr->dma_rx are valid pointers before accessing them. Fixes: 1513ceee70f2 ("spi: bcm2835: Drop dma_pending flag") Cc: Lukas Wunner Cc: Mark Brown Cc: Jens Lindahl Signed-off-by: Marc Kleine-Budde --- Changes Since v1: https://lore.kernel.org/all/20220719072234.2782764-1-mkl@pengutronix.de - added Mark Brown and Jens Lindahl on Cc drivers/spi/spi-bcm2835.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) base-commit: 73d5fe046270281a46344e06bf986c607632f7ea diff --git a/drivers/spi/spi-bcm2835.c b/drivers/spi/spi-bcm2835.c index 775c0bf2f923..0933948d7df3 100644 --- a/drivers/spi/spi-bcm2835.c +++ b/drivers/spi/spi-bcm2835.c @@ -1138,10 +1138,14 @@ static void bcm2835_spi_handle_err(struct spi_controller *ctlr, struct bcm2835_spi *bs = spi_controller_get_devdata(ctlr); /* if an error occurred and we have an active dma, then terminate */ - dmaengine_terminate_sync(ctlr->dma_tx); - bs->tx_dma_active = false; - dmaengine_terminate_sync(ctlr->dma_rx); - bs->rx_dma_active = false; + if (ctlr->dma_tx) { + dmaengine_terminate_sync(ctlr->dma_tx); + bs->tx_dma_active = false; + } + if (ctlr->dma_rx) { + dmaengine_terminate_sync(ctlr->dma_rx); + bs->rx_dma_active = false; + } bcm2835_spi_undo_prologue(bs); /* and reset */