From patchwork Mon Oct 9 21:52:59 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: 13414569 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 382AB156E1; Mon, 9 Oct 2023 21:53:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="IyYdAZ9E" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CBB9C433C7; Mon, 9 Oct 2023 21:53:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1696888383; bh=W+VZfakyDjRAObO1dDQmRahEdfhe6IqKNZRo1tRwkuk=; h=Date:From:To:Cc:Subject:From; b=IyYdAZ9EdWVH9jfcqTIBghy4+Muh2EwEWNScrz4b6/aGOUsd4mtqMfoBGTvK0lO6c onA3n0Ti125FvNmSQK8G0nHnkQuQfLHPIw94GdKqymW9RjYlnO5rr8K59gXix6rYDv K+smp/Ptnv2nHzZokKGH0fagbuF1UXumVrzSuy0S+2dpj6k0oYedewNK8JDJCA4UBh 2kaFeZIXRSskXp46DKazFRFkJSWh0LQUEl4WA4ZKmoYOfpOlfrz6Q1kGaCyWSDkKHV R+pJO6bQVK5kh2aPVWX0fFUVo6ErAoyTDyV3dCkv9qD4GYbDHRsqsj4TsHtEtYQEZn AaCet59ZGYm5w== Date: Mon, 9 Oct 2023 15:52:59 -0600 From: "Gustavo A. R. Silva" To: Johan Hovold , Alex Elder , Greg Kroah-Hartman Cc: greybus-dev@lists.linaro.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, "Gustavo A. R. Silva" , linux-hardening@vger.kernel.org Subject: [PATCH][next] staging: greybus: Add __counted_by for struct apr_rx_buf and use struct_size() 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 Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). While there, use struct_size() helper, instead of the open-coded version, to calculate the size for the allocation of the whole flexible structure, including of course, the flexible-array member. This code was found with the help of Coccinelle, and audited and fixed manually. Signed-off-by: Gustavo A. R. Silva Reviewed-by: Kees Cook Reviewed-by: Alex Elder --- drivers/staging/greybus/raw.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/staging/greybus/raw.c b/drivers/staging/greybus/raw.c index a00978c8e1d2..b9c6eff7cdc1 100644 --- a/drivers/staging/greybus/raw.c +++ b/drivers/staging/greybus/raw.c @@ -29,7 +29,7 @@ struct gb_raw { struct raw_data { struct list_head entry; u32 len; - u8 data[]; + u8 data[] __counted_by(len); }; static const struct class raw_class = { @@ -73,7 +73,7 @@ static int receive_data(struct gb_raw *raw, u32 len, u8 *data) goto exit; } - raw_data = kmalloc(sizeof(*raw_data) + len, GFP_KERNEL); + raw_data = kmalloc(struct_size(raw_data, data, len), GFP_KERNEL); if (!raw_data) { retval = -ENOMEM; goto exit;