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 08F16E77188 for ; Mon, 6 Jan 2025 09:49:54 +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-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=UB3S6kcd+Omc6ye56NC6ow7U03F1ihd9mp0kuIOyzfY=; b=0PziuhLqQOEAfhEx+plcUqe+xe i87NSGG9vprft2sJaE0/GAUJ/FcfUuimUpD/1p64A3HYVdX7RUNOw/Ij/+VLozJapoqMVpZpWDlwH hwr1ciKU/zOn7wEmBPbiVE90iQCSKnexmuB2YwEJjBmKPZzgYK/RwEpp7h+NSYzWsYKfFXcDIqqRW +V7ciESeE+Nes+o6TDu4mRRhJTXQ0kaG/3VqVoNs2+jlzVFmgGGesxV80JKGoBUh2ELBWYQdQFneZ khXAoj4spRcLOYckkZQm7Zt7kkikfNm0nzEY+631530r+OXLX+oPH3gwcTqzDw5ZjhbZa2gW8EkBY F/Yfuo/w==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tUjk0-00000000k1v-0XuH; Mon, 06 Jan 2025 09:49:44 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tUjiK-00000000jqu-3p8g for linux-arm-kernel@lists.infradead.org; Mon, 06 Jan 2025 09:48:03 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=UB3S6kcd+Omc6ye56NC6ow7U03F1ihd9mp0kuIOyzfY=; b=u8ATxVr2+q/It4195z3R2JW17Z n4BxjFVG9gkVWLrh+y8ahgYOsghmOyC185Cuk1U6JQic3S+wpsSwzBvL+Zs2ffOdF85PPuO4E4/K7 Hc9SUbiuqnbYc3LksInEkcZIXA/MiaVK+C8GGrjiqTNepW2nC9cefkXyPRH5SzMVgn/tsa4y+I1iz FYzPy28nKJHKOxdlLs5CEycDC0czUMHCLosz/2v30z0h/1icHpZtDFjwAms7vv/d8KLzZ14YKQnyP oc585AlVHEEenpQ2PnVbF1de9w0VXnr0v2asZSFBjB4GG3mvwdFjMhk6FxIyHYxQgI/BjfM424GS9 KeOZ62Bg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:39272) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tUjiH-0005bA-2h; Mon, 06 Jan 2025 09:47:57 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.96) (envelope-from ) id 1tUjiG-0004B1-2W; Mon, 06 Jan 2025 09:47:56 +0000 Date: Mon, 6 Jan 2025 09:47:56 +0000 From: "Russell King (Oracle)" To: Ma Ke Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2] [ARM] fix reference leak in locomo_init_one_child() Message-ID: References: <20250106074743.313384-1-make24@iscas.ac.cn> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20250106074743.313384-1-make24@iscas.ac.cn> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250106_014800_961783_3EF95BC3 X-CRM114-Status: GOOD ( 19.91 ) 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 Mon, Jan 06, 2025 at 03:47:43PM +0800, Ma Ke wrote: > Once device_register() failed, we should call put_device() to > decrement reference count for cleanup. Or it could cause memory leak. > > device_register() includes device_add(). As comment of device_add() > says, 'if device_add() succeeds, you should call device_del() when you > want to get rid of it. If device_add() has not succeeded, use only > put_device() to drop the reference count'. > > Found by code review. > > Cc: stable@vger.kernel.org > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Signed-off-by: Ma Ke > --- > Changes in v2: > - modified the patch as suggestions. > --- > arch/arm/common/locomo.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/arch/arm/common/locomo.c b/arch/arm/common/locomo.c > index 309b74783468..9e48cbb2568e 100644 > --- a/arch/arm/common/locomo.c > +++ b/arch/arm/common/locomo.c > @@ -253,6 +253,8 @@ locomo_init_one_child(struct locomo *lchip, struct locomo_dev_info *info) > > ret = device_register(&dev->dev); > if (ret) { > + put_device(&dev->dev); > + return ret; > out: > kfree(dev); > } This makes the code layout quite horrible. Instead, I suggest: dev = kzalloc(sizeof(...)... - if (!dev) { - ret = -ENOMEM; - goto out; - } + if (!dev) + return -ENOMEM; ... ret = device_register(&dev->dev); - if (ret) { - out: - kfree(dev); - } + if (ret) + put_device(&dev->dev); Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!