From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 51C73515886 for ; Wed, 30 Sep 2026 20:49:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790801343; cv=none; b=jTaV/+rZeii6+b2+mw1IBoGiN0C33CRO4rsAJGHpHyfIGkzD497ogOAK1Lhg6JTXtY+App6b9GmiAK2pVF8SwemCJzf+rCVvUWCe2rPn+waizjxt+KZXj8elwb1ks1jN2zpfONDHlagIuwd1FKbReZKmgrkStMs4GwHCP8Fcyvk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790801343; c=relaxed/simple; bh=7cw+2uirxLu0HD1zySTwhFF6oAhV9dULExV1Z7f8/aQ=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=XUCnyICicjFLeIIbTWTshtUy1OwhGbRTOaZHyrY+PecXoia6w0jU8T4wkFrPtHmlvnEEsSM8/fppMzsECwkvKLLyusp2Qm9bXQNmt4JUyrB3Ek/i49hqkA3zN0COgkb7jz1IH2n5jJB31KEwlK3HhAIsTYlSsz4q6LE1zJSaFpc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=Oh9MNxSR; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="Oh9MNxSR" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id A1901143D for ; Wed, 30 Sep 2026 13:48:56 -0700 (PDT) Received: from [10.2.11.34] (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id D42393F85F for ; Wed, 30 Sep 2026 13:48:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790801340; bh=7cw+2uirxLu0HD1zySTwhFF6oAhV9dULExV1Z7f8/aQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=Oh9MNxSROOG5bjdAAi5KWC16fsF2L0ElsgVkNR5DVic5N/o24dN9YeQfLEzSvOlwa lCzYvZjWeTQDhjijfzrph++2CVx0XNcVmbrkG4oQO8Bvfb8Dao2cgNDbVA8SwPdu4p qgyd1yZxc3lp9cwmnnQ+Mz1gFeDEkNUFlefUR0Og= Date: Wed, 30 Sep 2026 21:48:51 +0100 From: Liviu Dudau To: Weigang He Cc: Sudeep Holla , Lorenzo Pieralisi , Linus Walleij , Russell King , Lee Jones , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] ARM: vexpress: fix device_node refcount leak in vexpress_flags_set() Message-ID: References: <20260925173252.933705-1-geoffreyhe2@gmail.com> <20260925173252.933705-2-geoffreyhe2@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260925173252.933705-2-geoffreyhe2@gmail.com> On Sat, Sep 26, 2026 at 03:32:51AM +1000, Weigang He wrote: > vexpress_flags_set() obtains a reference to the "arm,vexpress-sysreg" > device node via of_find_compatible_node() and passes it to of_iomap(), > but never calls of_node_put() on it. of_iomap() only reads the node's > reg property to create the mapping and does not take ownership, so the > node reference is leaked. The function runs from the __init SMP prepare > path and caches the mapping in a static, so this is a one-shot leak of a > single refcount during boot, with no functional impact. > > The lookup was added to drivers/mfd/vexpress-sysreg.c by the commit > below and later moved here by commit 9b06fc39084e ("ARM: vexpress: Move > vexpress_flags_set() into arch code"). > > Annotate node with the __free(device_node) cleanup attribute so the > reference is released when it goes out of scope. > > Found by static analysis tool CodeQL. > > Fixes: 974cc7b93441 ("mfd: vexpress: Define the device as MFD cells") > Assisted-by: LLM codeql > Signed-off-by: Weigang He Reviewed-by: Liviu Dudau Best regards, Liviu > --- > > Notes: > Compile-tested only (ARCH=arm multi_v7_defconfig, W=1). Not tested on > hardware; I have no Versatile Express board. > > The CodeQL query behind this report was synthesized with LLM assistance, > and the fix and changelog were drafted with LLM assistance; I have > reviewed them. > > arch/arm/mach-versatile/v2m.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/mach-versatile/v2m.c b/arch/arm/mach-versatile/v2m.c > index 79afdf2a90b6f..c86b38386cf7c 100644 > --- a/arch/arm/mach-versatile/v2m.c > +++ b/arch/arm/mach-versatile/v2m.c > @@ -13,8 +13,8 @@ void vexpress_flags_set(u32 data) > static void __iomem *base; > > if (!base) { > - struct device_node *node = of_find_compatible_node(NULL, NULL, > - "arm,vexpress-sysreg"); > + struct device_node *node __free(device_node) = > + of_find_compatible_node(NULL, NULL, "arm,vexpress-sysreg"); > > base = of_iomap(node, 0); > } > -- > 2.43.0 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯