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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EC8D5C54EAA for ; Mon, 30 Jan 2023 13:55:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236435AbjA3NzD (ORCPT ); Mon, 30 Jan 2023 08:55:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236473AbjA3Nyt (ORCPT ); Mon, 30 Jan 2023 08:54:49 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51D7E38EB6 for ; Mon, 30 Jan 2023 05:54:47 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id E4CFEB8114A for ; Mon, 30 Jan 2023 13:54:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 29071C4339B; Mon, 30 Jan 2023 13:54:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1675086884; bh=YJh0KEvg139heAIAZmWjn3YqiW+d/l96WNQNoNX/zVs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NWGzJSB/gb05088ruwNgwxRBdCKdmZ6iyBFpWcxgYfMVjb2xqYAq2I1z3HLrF1FL9 ZGi8UM/V9noyzi0HC1Ak4lbGk8QfrVlFoP6Ml7feUsT9biLFpphWV9zczpTn5B9WYP Zp46CwCbTa0fJUChMC+NfIkaLF3dppUj5yH5BpvE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Cristian Marussi , Sudeep Holla , Sasha Levin Subject: [PATCH 6.1 028/313] firmware: arm_scmi: Harden shared memory access in fetch_notification Date: Mon, 30 Jan 2023 14:47:43 +0100 Message-Id: <20230130134337.982240592@linuxfoundation.org> X-Mailer: git-send-email 2.39.1 In-Reply-To: <20230130134336.532886729@linuxfoundation.org> References: <20230130134336.532886729@linuxfoundation.org> User-Agent: quilt/0.67 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: Cristian Marussi [ Upstream commit 9bae076cd4e3e3c3dc185cae829d80b2dddec86e ] A misbheaving SCMI platform firmware could reply with out-of-spec notifications, shorter than the mimimum size comprising a header. Fixes: d5141f37c42e ("firmware: arm_scmi: Add notifications support in transport layer") Signed-off-by: Cristian Marussi Link: https://lore.kernel.org/r/20221222183823.518856-4-cristian.marussi@arm.com Signed-off-by: Sudeep Holla Signed-off-by: Sasha Levin --- drivers/firmware/arm_scmi/shmem.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/arm_scmi/shmem.c b/drivers/firmware/arm_scmi/shmem.c index 135f8718000f..87b4f4d35f06 100644 --- a/drivers/firmware/arm_scmi/shmem.c +++ b/drivers/firmware/arm_scmi/shmem.c @@ -94,8 +94,10 @@ void shmem_fetch_response(struct scmi_shared_mem __iomem *shmem, void shmem_fetch_notification(struct scmi_shared_mem __iomem *shmem, size_t max_len, struct scmi_xfer *xfer) { + size_t len = ioread32(&shmem->length); + /* Skip only the length of header in shmem area i.e 4 bytes */ - xfer->rx.len = min_t(size_t, max_len, ioread32(&shmem->length) - 4); + xfer->rx.len = min_t(size_t, max_len, len > 4 ? len - 4 : 0); /* Take a copy to the rx buffer.. */ memcpy_fromio(xfer->rx.buf, shmem->msg_payload, xfer->rx.len); -- 2.39.0