From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0A1D0C43444 for ; Fri, 11 Jan 2019 11:20:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D04A22177B for ; Fri, 11 Jan 2019 11:20:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730395AbfAKLU4 (ORCPT ); Fri, 11 Jan 2019 06:20:56 -0500 Received: from metis.ext.pengutronix.de ([85.220.165.71]:54411 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730390AbfAKLUz (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=20Kleine-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 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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: stable@vger.kernel.org Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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); -- 2.20.1