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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 39FB2C433EF for ; Thu, 28 Apr 2022 10:19:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=XW7YEe8OfL1fk7ie9ZbAVunDFSuXNPMwilyRSaMQn9c=; b=YUuQ9ImcIyJBvl vwKGVGbagaJck3JowLwOZgpPH30rc8FNJpZiMqofFh9QsGQmE2xSWbQFgtJ9miuxFfxrIzc5Wo10K mCi0CbOr9YVlxgnvrRS68eEEMAW1KMCr2tOUhdrv4mjeG8j/8Jmxc5e9YcT7T/pYu13wgY5a764T9 OU0GOt9klTlOC0gJTuREE7S+B2PQzdBk1SSkyqP9si1R6k+oJ4/J4RpPBSHQYvvWIcSbakY/MFzLE 7C5j8SVEFKS4QAj3/m1Nu5kQ/NezZwf+9FRo/i8mNH0mSvo6UTDNMdDF3RW2YsRYBCkHtCL5CAs73 RxO4HETMndfMJd272+2Q==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nk1EK-00645e-N0; Thu, 28 Apr 2022 10:18:37 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nk13k-005zPL-5E for linux-arm-kernel@lists.infradead.org; Thu, 28 Apr 2022 10:07:41 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 4699D1477; Thu, 28 Apr 2022 03:07:37 -0700 (PDT) Received: from bogus (unknown [10.57.11.83]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id D1E0D3F774; Thu, 28 Apr 2022 03:07:34 -0700 (PDT) Date: Thu, 28 Apr 2022 11:07:29 +0100 From: Sudeep Holla To: Cristian Marussi Cc: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com, f.fainelli@gmail.com, etienne.carriere@linaro.org, vincent.guittot@linaro.org, souvik.chakravarty@arm.com Subject: Re: [PATCH 04/22] firmware: arm_scmi: Validate BASE_DISCOVER_LIST_PROTOCOLS reply Message-ID: <20220428100729.qlzl5lkkn2r5u3ra@bogus> References: <20220330150551.2573938-1-cristian.marussi@arm.com> <20220330150551.2573938-5-cristian.marussi@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20220330150551.2573938-5-cristian.marussi@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220428_030740_273161_7591BDE8 X-CRM114-Status: GOOD ( 16.65 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, Mar 30, 2022 at 04:05:33PM +0100, Cristian Marussi wrote: > Do not blindly trust SCMI backend server reply about list of implemented > protocols, instead validate the reported length of the list of protocols > against the real payload size of the message reply. > > Fixes: b6f20ff8bd9 ("firmware: arm_scmi: add common infrastructure and support for base protocol") > Signed-off-by: Cristian Marussi > --- > drivers/firmware/arm_scmi/base.c | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c > index f279146f8110..c1165d1282ef 100644 > --- a/drivers/firmware/arm_scmi/base.c > +++ b/drivers/firmware/arm_scmi/base.c > @@ -189,6 +189,9 @@ scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph, > list = t->rx.buf + sizeof(*num_ret); > > do { > + size_t real_list_sz; > + u32 calc_list_sz; > + > /* Set the number of protocols to be skipped/already read */ > *num_skip = cpu_to_le32(tot_num_ret); > > @@ -202,6 +205,24 @@ scmi_base_implementation_list_get(const struct scmi_protocol_handle *ph, > break; > } > > + if (t->rx.len < (sizeof(u32) * 2)) { > + dev_err(dev, "Truncated reply - rx.len:%zd\n", > + t->rx.len); > + ret = -EPROTO; > + break; > + } > + > + real_list_sz = t->rx.len - sizeof(u32); > + calc_list_sz = ((loop_num_ret / sizeof(u32)) + > + !!(loop_num_ret % sizeof(u32))) * sizeof(u32); Any reason this can't be (loop_num_ret - 1) / sizeof(u32) + 1 ? -- Regards, Sudeep _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel