From patchwork Mon Oct 16 22:07:28 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: 13424221 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0F6B9381D8 for ; Mon, 16 Oct 2023 22:07:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QSCsDgNA" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B1711C433C8; Mon, 16 Oct 2023 22:07:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697494051; bh=QVLofbHbw5E8A25XjU4ezmzNLLgw1rylbmVWRoqHvnE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QSCsDgNApKM4YLJtgg+406eD70FVfy1irOAo/p8HSqPbpurM1F6r84UfpvG9bNy2U PrK/Cevy4eXn5EJIgqtq2m8x2nkuW+mBsKNH5Xm4taTcnYoh12eF3Ui2hftfuUbWJ4 r1slPg3SjxoDk1RM4vdqLhZU1iCDGSCRSxYHuBWQrSkwKbuTG0J9qOwDD6FbasiOkQ txgy5OzL7LxEzAuOUwjVseBribN6XOOR7gG3xA3wgNMeDqs2aBchxdtp4xtJ480QBN QfzqlUx5FZvfEcbzZyzERCQpEk+PJVenVJeDgV7cJ2oYNSe2+zJpkjQjE5WvS9t+2R Yo1AObcopsoWw== Date: Mon, 16 Oct 2023 16:07:28 -0600 From: "Gustavo A. R. Silva" To: Dinh Nguyen , Michael Turquette , Stephen Boyd Cc: Kees Cook , linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH v2 1/2][next] clk: socfpga: Fix undefined behavior bug in struct stratix10_clock_data Message-ID: References: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: `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 stratix10_clock_data`, in this case `void __iomem *base;` at run-time: drivers/clk/socfpga/stratix10-clk.h: 9 struct stratix10_clock_data { 10 struct clk_hw_onecell_data clk_data; 11 void __iomem *base; 12 }; There are currently three different places where memory is allocated for `struct stratix10_clock_data`, including the flex-array `hws` in `struct clk_hw_onecell_data`: drivers/clk/socfpga/clk-agilex.c: 469 clk_data = devm_kzalloc(dev, struct_size(clk_data, clk_data.hws, 470 num_clks), GFP_KERNEL); drivers/clk/socfpga/clk-agilex.c: 509 clk_data = devm_kzalloc(dev, struct_size(clk_data, clk_data.hws, 510 num_clks), GFP_KERNEL); drivers/clk/socfpga/clk-s10.c: 400 clk_data = devm_kzalloc(dev, struct_size(clk_data, clk_data.hws, 401 num_clks), GFP_KERNEL); I'll use just one of them to describe the issue. See below. Notice that a total of 440 bytes are allocated for flexible-array member `hws` at line 469: include/dt-bindings/clock/agilex-clock.h: 70 #define AGILEX_NUM_CLKS 55 drivers/clk/socfpga/clk-agilex.c: 459 struct stratix10_clock_data *clk_data; 460 void __iomem *base; ... 466 467 num_clks = AGILEX_NUM_CLKS; 468 469 clk_data = devm_kzalloc(dev, struct_size(clk_data, clk_data.hws, 470 num_clks), GFP_KERNEL); `struct_size(clk_data, clk_data.hws, num_clks)` above translates to sizeof(struct stratix10_clock_data) + sizeof(struct clk_hw *) * 55 == 16 + 8 * 55 == 16 + 440 ^^^ | allocated bytes for flex-array `hws` 474 for (i = 0; i < num_clks; i++) 475 clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); 476 477 clk_data->base = base; and then some data is written into both `hws` and `base` objects. Fix this by placing the declaration of object `clk_data` at the end of `struct stratix10_clock_data`. Also, add a comment to make it clear that this object must always be last in the structure. -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. Fixes: ba7e258425ac ("clk: socfpga: Convert to s10/agilex/n5x to use clk_hw") Cc: stable@vger.kernel.org Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - Mention -Wflex-array-member-not-at-end in the changelog text. v1: - Link: https://lore.kernel.org/linux-hardening/5dd8483177dc8cd91d021170b6717f2e570bab03.1697059539.git.gustavoars@kernel.org/ drivers/clk/socfpga/stratix10-clk.h | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/clk/socfpga/stratix10-clk.h b/drivers/clk/socfpga/stratix10-clk.h index 75234e0783e1..83fe4eb3133c 100644 --- a/drivers/clk/socfpga/stratix10-clk.h +++ b/drivers/clk/socfpga/stratix10-clk.h @@ -7,8 +7,10 @@ #define __STRATIX10_CLK_H struct stratix10_clock_data { - struct clk_hw_onecell_data clk_data; void __iomem *base; + + /* Must be last */ + struct clk_hw_onecell_data clk_data; }; struct stratix10_pll_clock { From patchwork Mon Oct 16 22:07:52 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: 13424222 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 82550381D8 for ; Mon, 16 Oct 2023 22:07:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iulmUHub" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38C52C433C7; Mon, 16 Oct 2023 22:07:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1697494076; bh=TW3IndpO2zBuBRlfI7R6Lfn0TK8diqp9tO2D/L4BKPs=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=iulmUHubMW2dW1FIERm2jLQStEyM4rbu4ppCVqE7kAhhg0L9qIWrI1mEVmoF+j0iz YlBH8SYs4++4CQ2ZoJuQYfejRUuS7kYKBkkms38l/AY0Ki0cgXe+iTn9tn6/AiDS98 /vp0RYVN/fNRXEEEmpuwm2BJTGO/31RmRPnnTC9wyeLS675dg60PuBAdaF1E0kSCJU B4n9moXIe+xpzZkvIfNhgm86tX/QQCLIokQdbq2OmO54pytW9Y07x24x8bYvqnoCRJ KKhebXPwiotrbX+nGURsnWG/fSBEmS90yIUjF4RDovUVBoCrtfPOUZydgMtk/kYjWo QT+RDxLr7lZDg== Date: Mon, 16 Oct 2023 16:07:52 -0600 From: "Gustavo A. R. Silva" To: Dinh Nguyen , Michael Turquette , Stephen Boyd Cc: Kees Cook , linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH v2 2/2][next] clk: socfpga: agilex: Add bounds-checking coverage for struct stratix10_clock_data Message-ID: References: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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 case `num`, is updated before the first access to the flex-array member, in this case array `hws`. 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 sstratix10_clock_data`: drivers/clk/socfpga/stratix10-clk.h: 9 struct stratix10_clock_data { 10 void __iomem *base; 11 12 /* Must be last */ 13 struct clk_hw_onecell_data clk_data; 14 }; Hence, we need to move the assignments to `clk_data->clk_data.num` after allocations for `struct stratix10_clock_data` and before accessing the flexible array `clk_data->clk_data.hws`. And, as assignments for both `clk_data->clk_data.num` and `clk_data->base` are originally adjacent to each other, relocate both assignments together. Reviewed-by: Kees Cook Signed-off-by: Gustavo A. R. Silva --- Changes in v2: - None. v1: - Link: https://lore.kernel.org/linux-hardening/fd4cd8503316d536e1a84fa2ae5bdefdd4b24afe.1697059539.git.gustavoars@kernel.org/ drivers/clk/socfpga/clk-agilex.c | 12 ++++++------ drivers/clk/socfpga/clk-s10.c | 6 +++--- 2 files changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/clk/socfpga/clk-agilex.c b/drivers/clk/socfpga/clk-agilex.c index 6b65a74aefa6..8dd94f64756b 100644 --- a/drivers/clk/socfpga/clk-agilex.c +++ b/drivers/clk/socfpga/clk-agilex.c @@ -471,12 +471,12 @@ static int agilex_clkmgr_init(struct platform_device *pdev) if (!clk_data) return -ENOMEM; + clk_data->clk_data.num = num_clks; + clk_data->base = base; + for (i = 0; i < num_clks; i++) clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); - clk_data->base = base; - clk_data->clk_data.num = num_clks; - agilex_clk_register_pll(agilex_pll_clks, ARRAY_SIZE(agilex_pll_clks), clk_data); agilex_clk_register_c_perip(agilex_main_perip_c_clks, @@ -511,12 +511,12 @@ static int n5x_clkmgr_init(struct platform_device *pdev) if (!clk_data) return -ENOMEM; - for (i = 0; i < num_clks; i++) - clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); - clk_data->base = base; clk_data->clk_data.num = num_clks; + for (i = 0; i < num_clks; i++) + clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); + n5x_clk_register_pll(agilex_pll_clks, ARRAY_SIZE(agilex_pll_clks), clk_data); n5x_clk_register_c_perip(n5x_main_perip_c_clks, diff --git a/drivers/clk/socfpga/clk-s10.c b/drivers/clk/socfpga/clk-s10.c index 3752bd9c103c..b4bf4e2d38e1 100644 --- a/drivers/clk/socfpga/clk-s10.c +++ b/drivers/clk/socfpga/clk-s10.c @@ -402,12 +402,12 @@ static int s10_clkmgr_init(struct platform_device *pdev) if (!clk_data) return -ENOMEM; - for (i = 0; i < num_clks; i++) - clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); - clk_data->base = base; clk_data->clk_data.num = num_clks; + for (i = 0; i < num_clks; i++) + clk_data->clk_data.hws[i] = ERR_PTR(-ENOENT); + s10_clk_register_pll(s10_pll_clks, ARRAY_SIZE(s10_pll_clks), clk_data); s10_clk_register_c_perip(s10_main_perip_c_clks,