From patchwork Fri Jan 11 11:20:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1023527 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 43bgQw4prMz9sBQ for ; Fri, 11 Jan 2019 22:20:56 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730371AbfAKLUz (ORCPT ); Fri, 11 Jan 2019 06:20:55 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:53991 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725801AbfAKLUz (ORCPT ); Fri, 11 Jan 2019 06:20:55 -0500 Received: from dude.hi.pengutronix.de ([2001:67c:670:100:1d::7]) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ghurt-0000tO-C5; Fri, 11 Jan 2019 12:20:53 +0100 Received: from ukl by dude.hi.pengutronix.de with local (Exim 4.92-RC4) (envelope-from ) id 1ghurs-0002ut-61; Fri, 11 Jan 2019 12:20:52 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Marc Kleine-Budde Cc: netdev@vger.kernel.org, linux-stable , linux-can@vger.kernel.org, kernel@pengutronix.de, davem@davemloft.net, Alexander Stein Subject: [PATCH] can: flexcan: fix NULL pointer exception during bringup Date: Fri, 11 Jan 2019 12:20:41 +0100 Message-Id: <20190111112041.10710-1-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190111105619.gkf2735zlpe6qbxv@pengutronix.de> References: <20190111105619.gkf2735zlpe6qbxv@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::7 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: netdev@vger.kernel.org Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Commit cbffaf7aa09e ("can: flexcan: Always use last mailbox for TX") introduced a loop letting i run up to (including) ARRAY_SIZE(regs->mb) and in the body accessed regs->mb[i] which is an out-of-bounds array access that then resulted in an access to an reserved register area. Later this was changed by commit 0517961ccdf1 ("can: flexcan: Add provision for variable payload size") to iterate a bit differently but still runs one iteration too much resulting to call flexcan_get_mb(priv, priv->mb_count) which results in a WARN_ON and then a NULL pointer exception. This only affects devices compatible with "fsl,p1010-flexcan", "fsl,imx53-flexcan", "fsl,imx35-flexcan", "fsl,imx25-flexcan", "fsl,imx28-flexcan", so newer i.MX SoCs are not affected. Fixes: cbffaf7aa09e ("can: flexcan: Always use last mailbox for TX") Signed-off-by: Uwe Kleine-König --- drivers/net/can/flexcan.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/can/flexcan.c b/drivers/net/can/flexcan.c index 0f36eafe3ac1..4c0173d2aff1 100644 --- a/drivers/net/can/flexcan.c +++ b/drivers/net/can/flexcan.c @@ -1106,7 +1106,7 @@ static int flexcan_chip_start(struct net_device *dev) } } else { /* clear and invalidate unused mailboxes first */ - for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i <= priv->mb_count; i++) { + for (i = FLEXCAN_TX_MB_RESERVED_OFF_FIFO; i < priv->mb_count; i++) { mb = flexcan_get_mb(priv, i); priv->write(FLEXCAN_MB_CODE_RX_INACTIVE, &mb->can_ctrl);