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=-19.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,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 3DED4C4320A for ; Thu, 29 Jul 2021 13:57:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D32B60F46 for ; Thu, 29 Jul 2021 13:57:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238219AbhG2N5f (ORCPT ); Thu, 29 Jul 2021 09:57:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:47220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238184AbhG2N5S (ORCPT ); Thu, 29 Jul 2021 09:57:18 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A73D960FED; Thu, 29 Jul 2021 13:57:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627567034; bh=BfeaPjbltn4piMZhsG3NqOM8tGJfuikps89RsPYWgNA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ScMQBNhqsXcTVseqJyWv4ctctaLqUN+2Y+DGma7+1g36DngRdkCjSLSlvEfl36ACZ FnyYj2c7qaKAwaWxRys5LK+8kiI9UbSqYEQYTzJy2eWzvhFPFZSKFJPRmPViPNrNWl o5uAYoj5g7pH+11SCtZO8W1YPxMdNAya/sFpY1ow= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kernel test robot , Dan Carpenter , Cristian Marussi , Sudeep Holla , Sasha Levin Subject: [PATCH 5.4 15/21] firmware: arm_scmi: Fix possible scmi_linux_errmap buffer overflow Date: Thu, 29 Jul 2021 15:54:22 +0200 Message-Id: <20210729135143.396784053@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210729135142.920143237@linuxfoundation.org> References: <20210729135142.920143237@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Sudeep Holla [ Upstream commit 7a691f16ccad05d770f813d9c4b4337a30c6d63f ] The scmi_linux_errmap buffer access index is supposed to depend on the array size to prevent element out of bounds access. It uses SCMI_ERR_MAX to check bounds but that can mismatch with the array size. It also changes the success into -EIO though scmi_linux_errmap is never used in case of success, it is expected to work for success case too. It is slightly confusing code as the negative of the error code is used as index to the buffer. Fix it by negating it at the start and make it more readable. Link: https://lore.kernel.org/r/20210707135028.1869642-1-sudeep.holla@arm.com Reported-by: kernel test robot Reported-by: Dan Carpenter Reviewed-by: Cristian Marussi Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/driver.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c index 7b6903bad408..ba2e18d9e0e4 100644 --- a/drivers/firmware/arm_scmi/driver.c +++ b/drivers/firmware/arm_scmi/driver.c @@ -54,7 +54,6 @@ enum scmi_error_codes { SCMI_ERR_GENERIC = -8, /* Generic Error */ SCMI_ERR_HARDWARE = -9, /* Hardware Error */ SCMI_ERR_PROTOCOL = -10,/* Protocol Error */ - SCMI_ERR_MAX }; /* List of all SCMI devices active in system */ @@ -176,8 +175,10 @@ static const int scmi_linux_errmap[] = { static inline int scmi_to_linux_errno(int errno) { - if (errno < SCMI_SUCCESS && errno > SCMI_ERR_MAX) - return scmi_linux_errmap[-errno]; + int err_idx = -errno; + + if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap)) + return scmi_linux_errmap[err_idx]; return -EIO; } -- 2.30.2