From patchwork Mon Oct 16 22:06:16 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Gustavo A. R. Silva" X-Patchwork-Id: 13424225 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 61EACCDB465 for ; Mon, 16 Oct 2023 22:06:47 +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=9wW1qlTfYsiR/HCzoa9PAUYykpmrgRzvCPZPuZ7g4Pk=; b=m71u3nqa3+49X6 vEfWAABhlEyuUHedVJvJyQd6jNaTIE58sPbV1j8WNjvIBo+b1ZUeQSy/U8Sq4iZhBtGGv1zWFAXQn DdOkOttAHmXknQ5X7mLmmKB4IYqs29nKIfk+b/YMtztZrPhJbcHKrB9+ljBipTK+QuMOkaDUNeQwz Z9RUh03LdAk8xHOvpNFMUwA+uQxtQFmSXr/S4a6alZbSoEcQhlQ+vtQXyPjUDNFpI7G+iYa1psB3C Xh2izGArzPBEWMKb8DX1kkPRrPN4FGyR59y0zwTgx+0YHbNroLO6xVC5BZGjBmw5XxTZXxSEo1jmz ukL6bnITPaZDReap1Ulg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.96 #2 (Red Hat Linux)) id 1qsVjF-00AfWc-2y; Mon, 16 Oct 2023 22:06:25 +0000 Received: from sin.source.kernel.org ([2604:1380:40e1:4800::1]) by bombadil.infradead.org with esmtps (Exim 4.96 #2 (Red Hat Linux)) id 1qsVjD-00AfVq-0A for linux-arm-kernel@lists.infradead.org; Mon, 16 Oct 2023 22:06:24 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sin.source.kernel.org (Postfix) with ESMTP id E593DCE1B3B; Mon, 16 Oct 2023 22:06:20 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B94CDC433C7; Mon, 16 Oct 2023 22:06:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697493980; bh=D7fdEpe0zShD1pFuLK68iJJXBS2qGwVgntab6FWqrjo=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Ub0BOQHxbWbUL85k9CgeLDCVNKg+n4jXSewv2gYqW1hfR3aBKTBygdAWyh75PAjOW jxg8DoU0PVbfCtkElQZVFZhb+qZ0dHh/NM3NNWXtsgMFMEDTQvpiiaSWoqczCfTNNv KWG92ncXKedXiJKitRh4LxKowpJicMN50Gik79sg4/ZLAnuVbCymw+Npe8nTmRE4rF QQ68eBToPSHUGgVEMlMFAimZYnXuF9hQ+U2O5FMrPuoVmUK5IV4MqHayLzhJF6L4qf tXNXSQJriezup5YH64Mfc7OMl+GsOyUjow+VZIAUKCoVJ6PRPrqb8IjJKPcZ2Khqde GtamlmfPp70ug== Date: Mon, 16 Oct 2023 16:06:16 -0600 From: "Gustavo A. R. Silva" To: Michael Turquette , Stephen Boyd , Nobuhiro Iwamatsu Cc: Kees Cook , linux-clk@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH v2 2/2][next] clk: visconti: Add bounds-checking coverage for struct visconti_pll_provider Message-ID: References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20231016_150623_431258_8A42DC2E X-CRM114-Status: GOOD ( 15.54 ) 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 In order to gain the bounds-checking coverage that __counted_by provides to flexible-array members at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions), we must make sure that the counter member, in this particular case `num`, is updated before the first access to the flex-array member, in this particular case array `hws`. See below: commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by") introduced `__counted_by` for `struct clk_hw_onecell_data` together with changes to relocate some of assignments of counter `num` before `hws` is accessed: include/linux/clk-provider.h: 1380 struct clk_hw_onecell_data { 1381 unsigned int num; 1382 struct clk_hw *hws[] __counted_by(num); 1383 }; However, this structure is used as a member in other structs, in this case in `struct visconti_pll_provider`: drivers/clk/visconti/pll.h: 16 struct visconti_pll_provider { 17 void __iomem *reg_base; 18 struct device_node *node; 19 20 /* Must be last */ 21 struct clk_hw_onecell_data clk_data; 22 }; Hence, we need to move the assignments to `ctx->clk_data.num` after allocation for `struct visconti_pll_provider` and before accessing the flexible array `ctx->clk_data.hws`. And, as assignments for all members in `struct visconti_pll_provider` are originally adjacent to each other, relocate all assignments together, so we don't split up `ctx->clk_data.hws = nr_plls` from the rest. :) Reviewed-by: Kees Cook Acked-by: Nobuhiro Iwamatsu Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - None. v1: - Link: https://lore.kernel.org/linux-hardening/675633f7ae9893371d35b238f06fd02a3acffebb.1697076650.git.gustavoars@kernel.org/ drivers/clk/visconti/pll.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/clk/visconti/pll.c b/drivers/clk/visconti/pll.c index 1f3234f22667..e9cd80e085dc 100644 --- a/drivers/clk/visconti/pll.c +++ b/drivers/clk/visconti/pll.c @@ -329,12 +329,12 @@ struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np, if (!ctx) return ERR_PTR(-ENOMEM); - for (i = 0; i < nr_plls; ++i) - ctx->clk_data.hws[i] = ERR_PTR(-ENOENT); - ctx->node = np; ctx->reg_base = base; ctx->clk_data.num = nr_plls; + for (i = 0; i < nr_plls; ++i) + ctx->clk_data.hws[i] = ERR_PTR(-ENOENT); + return ctx; }