From patchwork Fri Feb 21 22:31:47 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thorsten Blum X-Patchwork-Id: 13986395 Received: from out-183.mta1.migadu.com (out-183.mta1.migadu.com [95.215.58.183]) (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 948F63C2F for ; Fri, 21 Feb 2025 22:33:25 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.183 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740177207; cv=none; b=MNjlN4ttOF1GWbobebdHWNhaYwV1mxL0/9b50oaxDiEGG9MBkZy3RlUkph4vNhd7xiSg7P+wqwYdlPz2AdfiUwmsFgXOldX37U7pUY6u24baHbFlDTymMBZKEFq82KUuzhZar7wnJ/AbKF1i6F8qiTrqI+75hs45ZwPVFFqNPKY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1740177207; c=relaxed/simple; bh=arFG12Yyu9BZtG4uWu4Apb7FX2TG1iTEcCqqDfZXUVs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=APPfjL25nKnlF6n7kPpageqHH+xJdxCNYAaseiAHvWMohPC5HKycue0MWU4YAo5b9EgMrE+ntAgnybpMoMG2KLDH8s1lwd6H6FPrV+G7wV8Fwbdpx5WlLNE/I65k90eyCGqzQ5/n5mVUaK4+9Uw8EZECYvpYDGmyfqT2boN0X7k= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=sxtUlTih; arc=none smtp.client-ip=95.215.58.183 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="sxtUlTih" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1740177191; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=/oHcAJH8k19ImnwHTRjOmi9oEpJN71Gn5cUukOMpM5A=; b=sxtUlTihMuFhHGUccPcl8B3FZHpU1w0WLyJKoIXgAUuKvEjHyubbSHT8aWeuzXqfch9YWg kQJBhrj8YIYKcv2AoIFW6UM8KcHW47J8ff0J/SjtJSW/Zo8wGAZs51320VheD7gT+qCMXV PuCXfprZf+OUp3rf+9fGW44sIR2NE7o= From: Thorsten Blum To: Peter Rosin , Kees Cook , "Gustavo A. R. Silva" Cc: Thorsten Blum , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] mux: Convert mux_control_ops to a flex array member in mux_chip Date: Fri, 21 Feb 2025 23:31:47 +0100 Message-ID: <20250221223146.248138-2-thorsten.blum@linux.dev> Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Migadu-Flow: FLOW_OUT Convert mux_control_ops to a flexible array member at the end of the mux_chip struct and add the __counted_by() compiler attribute to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and CONFIG_FORTIFY_SOURCE. Use struct_size() to calculate the number of bytes to allocate for a new mux chip and to remove the following Coccinelle/coccicheck warning: WARNING: Use struct_size Use size_add() to safely add any extra bytes. Compile-tested only. Link: https://github.com/KSPP/linux/issues/83 Signed-off-by: Thorsten Blum --- drivers/mux/core.c | 7 +++---- include/linux/mux/driver.h | 4 ++-- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/drivers/mux/core.c b/drivers/mux/core.c index 02be4ba37257..a3840fe0995f 100644 --- a/drivers/mux/core.c +++ b/drivers/mux/core.c @@ -98,13 +98,12 @@ struct mux_chip *mux_chip_alloc(struct device *dev, if (WARN_ON(!dev || !controllers)) return ERR_PTR(-EINVAL); - mux_chip = kzalloc(sizeof(*mux_chip) + - controllers * sizeof(*mux_chip->mux) + - sizeof_priv, GFP_KERNEL); + mux_chip = kzalloc(size_add(struct_size(mux_chip, mux, controllers), + sizeof_priv), + GFP_KERNEL); if (!mux_chip) return ERR_PTR(-ENOMEM); - mux_chip->mux = (struct mux_control *)(mux_chip + 1); mux_chip->dev.class = &mux_class; mux_chip->dev.type = &mux_type; mux_chip->dev.parent = dev; diff --git a/include/linux/mux/driver.h b/include/linux/mux/driver.h index 18824064f8c0..e58e59354e23 100644 --- a/include/linux/mux/driver.h +++ b/include/linux/mux/driver.h @@ -56,18 +56,18 @@ struct mux_control { /** * struct mux_chip - Represents a chip holding mux controllers. * @controllers: Number of mux controllers handled by the chip. - * @mux: Array of mux controllers that are handled. * @dev: Device structure. * @id: Used to identify the device internally. * @ops: Mux controller operations. + * @mux: Array of mux controllers that are handled. */ struct mux_chip { unsigned int controllers; - struct mux_control *mux; struct device dev; int id; const struct mux_control_ops *ops; + struct mux_control mux[] __counted_by(controllers); }; #define to_mux_chip(x) container_of((x), struct mux_chip, dev)