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 4CD25C5CFEB for ; Thu, 13 Aug 2026 11:34:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=y+zdQDNzy9XwsWlPqks3FdQJfc35rE02ceOkdYN/X4E=; b=wwycurXd6IKQjU/+ZcewFBqrg7 5vMoaYy/jtCtK12VFr3MAnuQkNCgXIQcyVSHxks56qhCrK24TIB9UoSEtmZj/X6B35ulG0uBC4mod AW4zOq+2lIaTAFGmnXi1njCoNzU9D/+navvaVC6DMOOJMPc1dVtSbJk1wnP2AzfufBz3Xcs0t/3Uf yiq8vDVKwX5ty2vGSkwv3rTCOQH/oIVsOJmOo4BfKFZ/x2mAvBF6Y5UEV1SRpB9XLijYR9D7SjSwE pu34VzlO6NAa2T8nU6uWh/rVLtzzCRzFqrTMSuZfDBiaiOfA23388tehavgyjG7nNZ/5DOYrUqnva KQp/FRUQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wuTgx-00000000YaI-39dq; Thu, 13 Aug 2026 11:33:47 +0000 Received: from tor.source.kernel.org ([172.105.4.254]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1wuTgs-00000000YVo-201F for linux-arm-kernel@lists.infradead.org; Thu, 13 Aug 2026 11:33:42 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id E60A6600AD; Thu, 13 Aug 2026 11:33:41 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C09BF1F00A3A; Thu, 13 Aug 2026 11:33:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1786620821; bh=y+zdQDNzy9XwsWlPqks3FdQJfc35rE02ceOkdYN/X4E=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=SRCSlI7P53oA4cwNrU5q0zW+NinY5tBKh8OsuWfm1M9+LWos/Yvr2AY1X4VA7QPEa LqX4BSwLKfTXaqf49rlQXDN/E+Pbf5+hVvDTbqy4kgy3TfHe0MN0eUbp807bRmPbRB AJuFeOdC6uhedFYYZf2xFdqsNgyAibiTc6pzqKMmzd3er3PJSfQjVLWG8eme5iHW33 Ay/AQJhV9USx2DHAsqZTepw2AFGqFXaDwgP6ifMGNYdbMe9V7VDYPFCpSRFTGZusfA As60PyduvXobDk4R6yg20vo2RgxUTZZHQMSVIRScobzdzSuZbDMRJcFePpljfYw5Ux wZBQ6LbgmsFhg== From: Sudeep Holla Date: Thu, 13 Aug 2026 12:33:04 +0100 Subject: [PATCH v3 9/9] firmware: arm_scmi: Validate PCC shared memory signature MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260813-acpi_scmi_pcc-v3-9-cb6b88b4ebb3@kernel.org> References: <20260813-acpi_scmi_pcc-v3-0-cb6b88b4ebb3@kernel.org> In-Reply-To: <20260813-acpi_scmi_pcc-v3-0-cb6b88b4ebb3@kernel.org> To: arm-scmi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@meta.com Cc: Cristian Marussi , Breno Leitao X-Mailer: b4 0.15.2 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Validate the PCC shared memory signature when setting up an SCMI PCC channel. Reject channels whose shared memory signature does not encode PCC_SIGNATURE combined with the PCC subspace ID, so misconfigured firmware is caught before the transport starts using the shared memory region. Signed-off-by: Sudeep Holla --- drivers/firmware/arm_scmi/transports/pcc.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/firmware/arm_scmi/transports/pcc.c b/drivers/firmware/arm_scmi/transports/pcc.c index 337d551e3ad8..0ead0ec77162 100644 --- a/drivers/firmware/arm_scmi/transports/pcc.c +++ b/drivers/firmware/arm_scmi/transports/pcc.c @@ -623,8 +623,11 @@ static void rx_callback(struct mbox_client *cl, void *m) } static int pcc_chan_validate_shmem(struct scmi_chan_info *cinfo, - struct scmi_pcc *smbox) + struct scmi_pcc *smbox, int ss_id) { + struct pcc_shared_mem __iomem *shmem = smbox->pchan->shmem; + u32 valid_signature = ss_id + PCC_SIGNATURE; + if (smbox->pchan->shmem_size < SCMI_PCC_SHMEM_OVERHEAD || smbox->pchan->shmem_size - SCMI_PCC_SHMEM_OVERHEAD < cinfo->max_msg_size) { @@ -632,6 +635,11 @@ static int pcc_chan_validate_shmem(struct scmi_chan_info *cinfo, return -ENOSPC; } + if (ioread32(&shmem->header.signature) != valid_signature) { + dev_err(cinfo->dev, "invalid PCC shared memory signature\n"); + return -EINVAL; + } + return 0; } @@ -667,7 +675,7 @@ static int pcc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev, return ret; } - ret = pcc_chan_validate_shmem(cinfo, smbox); + ret = pcc_chan_validate_shmem(cinfo, smbox, ss_id); if (ret) { pcc_mbox_free_channel(smbox->pchan); return ret; -- 2.43.0