From patchwork Thu Nov 14 23:55:16 2024 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: 13875781 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 495FE1AAE33; Thu, 14 Nov 2024 23:55:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731628521; cv=none; b=HvnepDiudbw67ZP7kQ9CFCjrR4psh/UUdUBteSoDMpDA5NBcq3yqcjbGkOO2sRK9m7R6wXNMeMqXKiskzCPPEy1yVdQit7MBzalG07EAfcj8x9QAeVfNUvnewoit1dC+OPGea0sMctKavrnXH/dJe+hW3ol2xIx/Vp2Yt62EZn0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731628521; c=relaxed/simple; bh=zY7KhF5ZX6coU8ApPUSZ3x9v5eBGEmYIOjd4V8VjVMQ=; h=Date:From:To:Cc:Subject:Message-ID:MIME-Version:Content-Type: Content-Disposition; b=uZ3q2fVWjFKh/x6c2g1B6K1QVWe1x/TJf5KaVueCi/TxkL3DibL4SKBi7gV42BSqIwRiUxhSSo2iRhCeRSvo1DPkriFDVm8ThBGXeK5y55D6yLjReiKVMfLB1KA6Mhxkr/Wq4Auhjx4OfUs4VYEc7ewKjNMevinHJ0VrFCY2BhE= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=lqrylpHT; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="lqrylpHT" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3F74EC4CECD; Thu, 14 Nov 2024 23:55:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731628520; bh=zY7KhF5ZX6coU8ApPUSZ3x9v5eBGEmYIOjd4V8VjVMQ=; h=Date:From:To:Cc:Subject:From; b=lqrylpHTmcapjRxzWJzvgZOkZh7UczariR30ksY+iYDhhN24qABUl0bRslUOUj2MZ Y6ypVn3YkCl5Yhcc/Xu0/pjf+Z70iyyPXiri33nQNC35wIi+eubEuV9/CRvbh+9Bnk /g28Q8YTJVqzGiCWGvo3wipqJvQjrKxe+8nFuAW6Us2s8EVcdWyzMrCE+HboP5xB7J b2Qce2D1Q5IQm0p906Ot2tKqC+IAD1iOPRE7OEQPUmIykJDR59x1gouWe4nnwrKjxr xux7pc+o+xNbDRhGFf17mcRZLbBSrdDOmJi5LgLXsL+3dzJEtWMjwNgmQYGODr1gnX +aqK10fhU3hJg== Date: Thu, 14 Nov 2024 17:55:16 -0600 From: "Gustavo A. R. Silva" To: Yinbo Zhu , Michael Turquette , Stephen Boyd , Huacai Chen , Binbin Zhou Cc: linux-clk@vger.kernel.org, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH] clk: clk-loongson2: Fix potential buffer overflow in flexible-array member access Message-ID: Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Disposition: inline Flexible-array member `hws` in `struct clk_hw_onecell_data` is annotated with the `counted_by()` attribute. This means that when memory is allocated for this array, the _counter_, which in this case is member `num` in the flexible structure, should be set to the maximum number of elements the flexible array can contain, or fewer. In this case, the total number of elements for the flexible array is determined by variable `clks_num` when allocating heap space via `devm_kzalloc()`, as shown below: 289 struct loongson2_clk_provider *clp; ... 296 for (p = data; p->name; p++) 297 clks_num++; 298 299 clp = devm_kzalloc(dev, struct_size(clp, clk_data.hws, clks_num), 300 GFP_KERNEL); So, `clp->clk_data.num` should be set to `clks_num` or less, and not exceed `clks_num`, as is currently the case. Otherwise, if data is written into `clp->clk_data.hws[clks_num]`, the instrumentation provided by the compiler won't detect the overflow, leading to a memory corruption bug at runtime. Fix this issue by setting `clp->clk_data.num` to `clks_num`. Fixes: 9796ec0bd04b ("clk: clk-loongson2: Refactor driver for adding new platforms") Cc: stable@vger.kernel.org Signed-off-by: Gustavo A. R. Silva --- drivers/clk/clk-loongson2.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/clk/clk-loongson2.c b/drivers/clk/clk-loongson2.c index e99ba79feec6..7082b4309c6f 100644 --- a/drivers/clk/clk-loongson2.c +++ b/drivers/clk/clk-loongson2.c @@ -306,7 +306,7 @@ static int loongson2_clk_probe(struct platform_device *pdev) return PTR_ERR(clp->base); spin_lock_init(&clp->clk_lock); - clp->clk_data.num = clks_num + 1; + clp->clk_data.num = clks_num; clp->dev = dev; for (i = 0; i < clks_num; i++) {