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=-8.7 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 541FDC31E49 for ; Thu, 13 Jun 2019 16:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2B5B520644 for ; Thu, 13 Jun 2019 16:26:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560443174; bh=ziRWNeAPfsFyq7hPX6N+EM0v9ri8dKuOt4apz8TikcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qbMefXxOiJ3EWla4N2lp6UPKEGqcg43gbe6fRjj9j29IfQ69f2S1Kzzsom6sxEe8R dax85uuy0El41Koj5vcUFqj4x3K1l59iTAf/bmuNTp6o8tI5nx6is73njj2hRIowvB kp6nOksi9dwjXg388MC9n2FJK/J052BtYRhiuA38= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731845AbfFMQZq (ORCPT ); Thu, 13 Jun 2019 12:25:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:54034 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730972AbfFMIgc (ORCPT ); Thu, 13 Jun 2019 04:36:32 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 691BC21479; Thu, 13 Jun 2019 08:36:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1560414991; bh=ziRWNeAPfsFyq7hPX6N+EM0v9ri8dKuOt4apz8TikcU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XFFVEmfV6eLmwSzjGNRQNikKczkhu2+Zp1NaXoAk/3+HKIQgyBXmGYWcfPKnLr8GF AImyacaN8i6rBkpJIw1f7D5RAFxgw56OPl4cMFD49v3ZpTYgAWXGiPkvzkG7MtS/LD x+SDco3F+21gJ1MePgVbDedYZ6+h5V2SDLzhWw2o= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Enrico Granata , Jett Rink , Enric Balletbo i Serra , Sasha Levin Subject: [PATCH 4.14 47/81] platform/chrome: cros_ec_proto: check for NULL transfer function Date: Thu, 13 Jun 2019 10:33:30 +0200 Message-Id: <20190613075652.740502088@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190613075649.074682929@linuxfoundation.org> References: <20190613075649.074682929@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org [ Upstream commit 94d4e7af14a1170e34cf082d92e4c02de9e9fb88 ] As new transfer mechanisms are added to the EC codebase, they may not support v2 of the EC protocol. If the v3 initial handshake transfer fails, the kernel will try and call cmd_xfer as a fallback. If v2 is not supported, cmd_xfer will be NULL, and the code will end up causing a kernel panic. Add a check for NULL before calling the transfer function, along with a helpful comment explaining how one might end up in this situation. Signed-off-by: Enrico Granata Reviewed-by: Jett Rink Signed-off-by: Enric Balletbo i Serra Signed-off-by: Sasha Levin --- drivers/platform/chrome/cros_ec_proto.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index 2ac4a7178470..dbad14716da4 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -67,6 +67,17 @@ static int send_command(struct cros_ec_device *ec_dev, else xfer_fxn = ec_dev->cmd_xfer; + if (!xfer_fxn) { + /* + * This error can happen if a communication error happened and + * the EC is trying to use protocol v2, on an underlying + * communication mechanism that does not support v2. + */ + dev_err_once(ec_dev->dev, + "missing EC transfer API, cannot send command\n"); + return -EIO; + } + ret = (*xfer_fxn)(ec_dev, msg); if (msg->result == EC_RES_IN_PROGRESS) { int i; -- 2.20.1