From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 2854BCA5FC4 for ; Wed, 30 Sep 2026 20:51:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To: Content-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=dPDK1RjqVTTBwaQmns3VDkFuMdVJQ9yvuvr1V4jsZtU=; b=iPdKnJymn0hfUZit8mDVgBbYq+ nd8R3qp8addB6pTS7Bsmo9vNWOWfzru0A3K1JtSJqpdkFUZAvGmECEhK0AhAA8CyQzo9aLRtrVFQ/ Ek2vcOiBkSsfrlnxVsUSfirDbc1hBLiyvOfjYazNny1K4RDChuC4aqX54Yn4moj0BO7QEL1CUv4Za zXFq6a1aUYQHG9qPwsNyx0ASTHqAxayxI/NEWEVIx/Une6r/1cmoWTKshaqut1QEHrp2SIHzN77LO CkxENd4VXZvD0OQANR7VUzYAJqCJfO9McMX8qkZYV2LPBSrQnRV0lwP5dLbaFqEJ11EjRPJ7PtJ3/ /zC+SpJQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xC1Ge-00000007COU-0mYC; Wed, 30 Sep 2026 20:51:08 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1xC1GX-00000007CMx-2gU9 for linux-arm-kernel@lists.infradead.org; Wed, 30 Sep 2026 20:51:02 +0000 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 1C20E143D for ; Wed, 30 Sep 2026 13:50:56 -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 45CF33F85F for ; Wed, 30 Sep 2026 13:50:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790801459; bh=o6JsEQle2TgBGXyra/fkAAW50pTRLJXiPJdy1imZk68=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=di2qgt1+E0o5tFCdR9GyLVt19Eyo1cbUiJV/sElqoiBz33UMZrpxqirTsZ6AtXW3g BNHdCs9rPgrgTosipiK4/G8FlHd8tG4CcH45jpIg5R7AXG8blb3F6+huAGgtlkReBy 8tf2RSnfVryFaCtZGlwiYYQr81EcyV7min1j48kg= Date: Wed, 30 Sep 2026 21:50:51 +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 2/2] ARM: vexpress: fix device_node refcount leak in vexpress_smp_dt_prepare_cpus() Message-ID: References: <20260925173252.933705-1-geoffreyhe2@gmail.com> <20260925173252.933705-3-geoffreyhe2@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20260925173252.933705-3-geoffreyhe2@gmail.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260930_135101_727532_D1A999D0 X-CRM114-Status: GOOD ( 24.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, Sep 26, 2026 at 03:32:52AM +1000, Weigang He wrote: > vexpress_smp_dt_prepare_cpus() obtains a reference to the SCU device > node via of_find_matching_node() and passes it to of_iomap(), but never > calls of_node_put() on it. of_iomap() does not take ownership of the > node, so the reference is leaked. The function is the .smp_prepare_cpus > hook invoked once from the __init SMP bring-up path, so this is a > one-shot leak of a single refcount during boot, with no functional > impact. > > Annotate scu with the __free(device_node) cleanup attribute so the > reference is released when the function returns. > > Found while reviewing a CodeQL report for vexpress_flags_set() on the > same SMP bring-up path. > > Fixes: d2606f81d563 ("ARM: vexpress: Simplify SMP operations for DT-powered system") > 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/platsmp-vexpress.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm/mach-versatile/platsmp-vexpress.c b/arch/arm/mach-versatile/platsmp-vexpress.c > index 1ee3c45e71c99..b810ad50b98ce 100644 > --- a/arch/arm/mach-versatile/platsmp-vexpress.c > +++ b/arch/arm/mach-versatile/platsmp-vexpress.c > @@ -61,8 +61,8 @@ static const struct of_device_id vexpress_smp_dt_scu_match[] __initconst = { > > static void __init vexpress_smp_dt_prepare_cpus(unsigned int max_cpus) > { > - struct device_node *scu = of_find_matching_node(NULL, > - vexpress_smp_dt_scu_match); > + struct device_node *scu __free(device_node) = > + of_find_matching_node(NULL, vexpress_smp_dt_scu_match); > > if (scu) > scu_enable(of_iomap(scu, 0)); > -- > 2.43.0 > -- ==================== | I would like to | | fix the world, | | but they're not | | giving me the | \ source code! / --------------- ¯\_(ツ)_/¯