From patchwork Tue Mar 18 16:27:39 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thorsten Blum X-Patchwork-Id: 14021313 Received: from out-171.mta1.migadu.com (out-171.mta1.migadu.com [95.215.58.171]) (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 BD8F720E6EC for ; Tue, 18 Mar 2025 16:28:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742315308; cv=none; b=uDWYtHILLT7cdG+xoNFs7T0X3bdTX40pp0WNmG8CIgsQtm1sm3JpIdW9NT5UD26q4s+XcBr3klpI/7sENJv/OZnrGWkGA3kI5VzV1A8S7rtFTEDmlJjcD2tszekaeXUV8NR6ocJ9Ca0TvT8enwwbjPK2wyTGlsgSNvbjxCLixpY= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1742315308; c=relaxed/simple; bh=arFG12Yyu9BZtG4uWu4Apb7FX2TG1iTEcCqqDfZXUVs=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lbnpnaRDGO3tQWnf7AVRZ57/Cuc7Ba/jjCVCWEONwVUoGEHC9UlqWVai76yMhD4uYE2YvEGTSif4ckZGtHIlFRk/PjOEQAYp09LFuZ/0TuaRJ7/xJjM6XdzasMQMSqLOPmzHvJaBR7CjBNJwpkLslfR79VDAiyH15Sn93GHK3kc= 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=cAHEYN7L; arc=none smtp.client-ip=95.215.58.171 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="cAHEYN7L" 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=1742315300; 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=cAHEYN7LQydmPc1BxiH7ObnOEQqhD1NixCPzgROUDeIF9cpcmAmMC1LjLIrGSxN9uC7zd9 4bgLO0POXNNlHFLNLu955wZPdlgbhdd92IzHb9+O6nT86ygcHFmQGWuHDwLgrQI11rIASS 2Qs3330sUTpgylJupcEMJfDjyj8eX2k= 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: [RESEND PATCH] mux: Convert mux_control_ops to a flex array member in mux_chip Date: Tue, 18 Mar 2025 17:27:39 +0100 Message-ID: <20250318162739.100593-2-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)