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 5DDB2C982C1 for ; Tue, 15 Sep 2026 17:05:32 +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=SOvbMkTzydFknS4iiHuLQpioDhMp+4T6jEUvQZ9DkZ0=; b=4ADP21JIp79RlJukIaUp6UiP69 SKraCxADEpZRw403XqrRYmfaSJhoCg7EXXOk6B4Xx9lrCryTaLcmGS1oXErNVgiNMuahujkDNdJbB FTzBtryzRascS2Mem1I1fcCeBCY9XzZ3FYi2qHIrBFgSHD+s0OG/7p5KxJjNNw30aNVbwlcdrXBeN H3e6KzeUM0Ze9zl6N5cniLBpcQEFI9jjKD0IHn+KGfRaxISnRnvu/TVE9iD7c6rDghu73HKCeSwOa iVEkBr/88I0LPN+7ySdY7ynoNcwQfp+JT3IMnNqLQAUekUrKNaUJn1yowfcrWoX0+w4WL8VKPVmfc n6XJxgCQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x6Waz-00000007Wpn-34Ta; Tue, 15 Sep 2026 17:05:25 +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 1x6Wal-00000007Wh0-1no9 for linux-arm-kernel@lists.infradead.org; Tue, 15 Sep 2026 17:05:11 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id D9AE06022A; Tue, 15 Sep 2026 17:05:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B6A41F00893; Tue, 15 Sep 2026 17:05:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1789491910; bh=SOvbMkTzydFknS4iiHuLQpioDhMp+4T6jEUvQZ9DkZ0=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=lpwiEDNcQ78ZDzHyBYqJ2INbrd5xcs0gFmdWmhR8GOwa/Kvscr5t2k+7a3Fe6KPiJ wq5ETqgedyYURupoAjqDVxYJ1lKZQIub8ON6C8ocCj8LX76SQ8Uh+0VndlEq9DPx19 FWZKPzILw4GImh2NJFhDHqWzWukmPKqjQ6obCwMRtMxqJQBa3UUkI9CT1eDLyaC88i ZT/O0NY2t4XGfiH1EEY57Gr/+Sslyc3FEbVd82YJLf526hzUg1zf5eqIpc9qEk4p7A DyTL1hT2cvvf9YRyC5NBu48EiG0HRwrp7gL5L5BjDJ6Qr0NiCfU3a0BoS8zai9vD8S AWOT1kezYBxNw== From: Sudeep Holla Date: Tue, 15 Sep 2026 18:03:43 +0100 Subject: [PATCH v5 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: <20260915-acpi_scmi_pcc-v5-9-298579e9f359@kernel.org> References: <20260915-acpi_scmi_pcc-v5-0-298579e9f359@kernel.org> In-Reply-To: <20260915-acpi_scmi_pcc-v5-0-298579e9f359@kernel.org> To: arm-scmi@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kernel-team@meta.com Cc: Cristian Marussi , Breno Leitao , Jonathan Cameron X-Mailer: b4 0.16.0 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. Reviewed-by: Jonathan Cameron 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 b7501f980d0b..86d4a097d8ec 100644 --- a/drivers/firmware/arm_scmi/transports/pcc.c +++ b/drivers/firmware/arm_scmi/transports/pcc.c @@ -698,8 +698,11 @@ 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) { @@ -707,6 +710,11 @@ 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; } @@ -742,7 +750,7 @@ 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