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 E6E43C61D97 for ; Wed, 22 Nov 2023 19:34:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343554AbjKVTeh (ORCPT ); Wed, 22 Nov 2023 14:34:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59714 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344437AbjKVTeh (ORCPT ); Wed, 22 Nov 2023 14:34:37 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BC42A1A8 for ; Wed, 22 Nov 2023 11:34:33 -0800 (PST) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1FF67C433C9; Wed, 22 Nov 2023 19:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1700681673; bh=sUOkpeVStIpkb0nCMt0Dt9ZKCxNjIGoC5ZfTJ6O/vCM=; h=Subject:To:Cc:From:Date:From; b=cBpdtacfzJ7FrJ+DirdjoSGc94C30B13fRxIwe+sluTUj3xSsrBs2OPp8M/Ckc7ty zrXcPGXg5/aCI1HscyDkT/yk3y1liSI1p0onbAeWBcA5QSASwFR0fgxeewwykXYnLH 7hHWagAo0qSkijB/EFKL3fgN1k3ck3UUtwQH9KuU= Subject: FAILED: patch "[PATCH] clk: visconti: Fix undefined behavior bug in struct" failed to apply to 6.1-stable tree To: gustavoars@kernel.org, keescook@chromium.org, nobuhiro1.iwamatsu@toshiba.co.jp, sboyd@kernel.org Cc: From: Date: Wed, 22 Nov 2023 19:34:31 +0000 Message-ID: <2023112230-baggage-playback-8fc5@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x 5ad1e217a2b23aa046b241183bd9452d259d70d0 # git commit -s git send-email --to '' --in-reply-to '2023112230-baggage-playback-8fc5@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: 5ad1e217a2b2 ("clk: visconti: Fix undefined behavior bug in struct visconti_pll_provider") 7e626a080bb2 ("clk: visconti: remove unused visconti_pll_provider::regmap") thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5ad1e217a2b23aa046b241183bd9452d259d70d0 Mon Sep 17 00:00:00 2001 From: "Gustavo A. R. Silva" Date: Mon, 16 Oct 2023 16:05:27 -0600 Subject: [PATCH] clk: visconti: Fix undefined behavior bug in struct visconti_pll_provider `struct clk_hw_onecell_data` is a flexible structure, which means that it contains flexible-array member at the bottom, in this case array `hws`: include/linux/clk-provider.h: 1380 struct clk_hw_onecell_data { 1381 unsigned int num; 1382 struct clk_hw *hws[] __counted_by(num); 1383 }; This could potentially lead to an overwrite of the objects following `clk_data` in `struct visconti_pll_provider`, in this case `struct device_node *node;`, at run-time: drivers/clk/visconti/pll.h: 16 struct visconti_pll_provider { 17 void __iomem *reg_base; 18 struct clk_hw_onecell_data clk_data; 19 struct device_node *node; 20 }; Notice that a total of 56 bytes are allocated for flexible-array `hws` at line 328. See below: include/dt-bindings/clock/toshiba,tmpv770x.h: 14 #define TMPV770X_NR_PLL 7 drivers/clk/visconti/pll-tmpv770x.c: 69 ctx = visconti_init_pll(np, reg_base, TMPV770X_NR_PLL); drivers/clk/visconti/pll.c: 321 struct visconti_pll_provider * __init visconti_init_pll(struct device_node *np, 322 void __iomem *base, 323 unsigned long nr_plls) 324 { 325 struct visconti_pll_provider *ctx; ... 328 ctx = kzalloc(struct_size(ctx, clk_data.hws, nr_plls), GFP_KERNEL); `struct_size(ctx, clk_data.hws, nr_plls)` above translates to sizeof(struct visconti_pll_provider) + sizeof(struct clk_hw *) * 7 == 24 + 8 * 7 == 24 + 56 ^^^^ | allocated bytes for flex array `hws` $ pahole -C visconti_pll_provider drivers/clk/visconti/pll.o struct visconti_pll_provider { void * reg_base; /* 0 8 */ struct clk_hw_onecell_data clk_data; /* 8 8 */ struct device_node * node; /* 16 8 */ /* size: 24, cachelines: 1, members: 3 */ /* last cacheline: 24 bytes */ }; And then, after the allocation, some data is written into all members of `struct visconti_pll_provider`: 332 for (i = 0; i < nr_plls; ++i) 333 ctx->clk_data.hws[i] = ERR_PTR(-ENOENT); 334 335 ctx->node = np; 336 ctx->reg_base = base; 337 ctx->clk_data.num = nr_plls; Fix all these by placing the declaration of object `clk_data` at the end of `struct visconti_pll_provider`. Also, add a comment to make it clear that this object must always be last in the structure, and prevent this bug from being introduced again in the future. -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. Fixes: b4cbe606dc36 ("clk: visconti: Add support common clock driver and reset driver") Cc: stable@vger.kernel.org Reviewed-by: Kees Cook Acked-by: Nobuhiro Iwamatsu Signed-off-by: Gustavo A. R. Silva Link: https://lore.kernel.org/r/57a831d94ee2b3889b11525d4ad500356f89576f.1697492890.git.gustavoars@kernel.org Signed-off-by: Stephen Boyd diff --git a/drivers/clk/visconti/pll.h b/drivers/clk/visconti/pll.h index 01d07f1bf01b..c4bd40676da4 100644 --- a/drivers/clk/visconti/pll.h +++ b/drivers/clk/visconti/pll.h @@ -15,8 +15,10 @@ struct visconti_pll_provider { void __iomem *reg_base; - struct clk_hw_onecell_data clk_data; struct device_node *node; + + /* Must be last */ + struct clk_hw_onecell_data clk_data; }; #define VISCONTI_PLL_RATE(_rate, _dacen, _dsmen, \