From nobody Tue Jun 23 13:20:44 2026 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id C8889C433F5 for ; Fri, 4 Mar 2022 08:56:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235292AbiCDI5j (ORCPT ); Fri, 4 Mar 2022 03:57:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35752 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229789AbiCDI5g (ORCPT ); Fri, 4 Mar 2022 03:57:36 -0500 Received: from zg8tmty1ljiyny4xntqumjca.icoremail.net (zg8tmty1ljiyny4xntqumjca.icoremail.net [165.227.154.27]) by lindbergh.monkeyblade.net (Postfix) with SMTP id 0482619E0A0 for ; Fri, 4 Mar 2022 00:56:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fudan.edu.cn; s=dkim; h=Received:From:To:Cc:Subject:Date: Message-Id:MIME-Version:Content-Transfer-Encoding; bh=2sHraFkP3T Sen0AL6X1rpeJpXgCuHZWyQHp0W57ycVI=; b=YfRz9mCSHWwDzwh8NEvvSrMIo5 85LxpyJe7zzjIQ5iwv66J6aXc4ReCwqOPqLuXbR6cUp2afP2cnDltjlipBxJs1oj gIKnyhhmouFfP082alCF0IEMp18ffum5Suu5KdAau2kaVT8RdB2rVfKAtGbi1pJS xBvkLwutjRqUswywg= Received: from localhost.localdomain (unknown [10.222.153.253]) by app1 (Coremail) with SMTP id XAUFCgA3P8MU1CFi0kgqDA--.64905S4; Fri, 04 Mar 2022 16:55:58 +0800 (CST) From: Xin Xiong To: Tudor Ambarus , Miquel Raynal , Richard Weinberger , Vignesh Raghavendra , Nicolas Ferre , Alexandre Belloni , Claudiu Beznea , Boris Brezillon , linux-mtd@lists.infradead.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: yuanxzhang@fudan.edu.cn, Xin Xiong , Xiyu Yang , Xin Tan Subject: [PATCH v4] mtd: rawnand: atmel: fix refcount issue in atmel_nand_controller_init Date: Fri, 4 Mar 2022 16:53:32 +0800 Message-Id: <20220304085330.3610-1-xiongx18@fudan.edu.cn> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: XAUFCgA3P8MU1CFi0kgqDA--.64905S4 X-Coremail-Antispam: 1UD129KBjvJXoW7Zw47ZF4DGrW7uF4rZw47urg_yoW8try5pF WUtFW3ZayUtFs3ZFnFkayxuF1rZ3WkJFyUG39Fqa4xZ3ZxXa4jkryYqry0vFy8CFyfuF17 ZF42q3W8CF1YkFUanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDU0xBIdaVrnRJUUU9G14x267AKxVW5JVWrJwAFc2x0x2IEx4CE42xK8VAvwI8IcIk0 rVWrJVCq3wAFIxvE14AKwVWUJVWUGwA2ocxC64kIII0Yj41l84x0c7CEw4AK67xGY2AK02 1l84ACjcxK6xIIjxv20xvE14v26w1j6s0DM28EF7xvwVC0I7IYx2IY6xkF7I0E14v26rxl 6s0DM28EF7xvwVC2z280aVAFwI0_GcCE3s1l84ACjcxK6I8E87Iv6xkF7I0E14v26rxl6s 0DM2vYz4IE04k24VAvwVAKI4IrM2AIxVAIcxkEcVAq07x20xvEncxIr21l5I8CrVACY4xI 64kE6c02F40Ex7xfMcIj6xIIjxv20xvE14v26r106r15McIj6I8E87Iv67AKxVWUJVW8Jw Am72CE4IkC6x0Yz7v_Jr0_Gr1lF7xvr2IYc2Ij64vIr41lF7I21c0EjII2zVCS5cI20VAG YxC7M4IIrI8v6xkF7I0E8cxan2IY04v7MxkIecxEwVCm-wCF04k20xvY0x0EwIxGrwCFx2 IqxVCFs4IE7xkEbVWUJVW8JwC20s026c02F40E14v26r1j6r18MI8I3I0E7480Y4vE14v2 6r106r1rMI8E67AF67kF1VAFwI0_Jw0_GFylIxkGc2Ij64vIr41lIxAIcVC0I7IYx2IY67 AKxVWUJVWUCwCI42IY6xIIjxv20xvEc7CjxVAFwI0_Gr0_Cr1lIxAIcVCF04k26cxKx2IY s7xG6rW3Jr0E3s1lIxAIcVC2z280aVAFwI0_Jr0_Gr1lIxAIcVC2z280aVCY1x0267AKxV W8JVW8JrUvcSsGvfC2KfnxnUUI43ZEXa7VU1YiiDUUUUU== X-CM-SenderInfo: arytiiqsuqiimz6i3vldqovvfxof0/1tbiAg8PEFKp2kD5HAAAsW Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The reference counting issue happens in several error handling paths on a refcounted object "nc->dmac". In these paths, the function simply returns the error code, forgetting to balance the reference count of "nc->dmac", increased earlier by dma_request_channel(), which may cause refcount leaks. Fix it by decrementing the refcount of specific object in those error paths. Fixes: f88fc122cc34 ("mtd: nand: Cleanup/rework the atmel_nand driver") Co-developed-by: Xiyu Yang Signed-off-by: Xiyu Yang Co-developed-by: Xin Tan Signed-off-by: Xin Tan Signed-off-by: Xin Xiong Reviewed-by: Claudiu Beznea --- V3 -> V4: Removed useless condition check V2 -> V3: Removed redundant lines V1 -> V2: Rewrited the error handling block --- drivers/mtd/nand/raw/atmel/nand-controller.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/drivers/mtd/nand/raw/atmel/nand-controller.c b/drivers/mtd/nan= d/raw/atmel/nand-controller.c index f3276ee9e4fe..ddd93bc38ea6 100644 --- a/drivers/mtd/nand/raw/atmel/nand-controller.c +++ b/drivers/mtd/nand/raw/atmel/nand-controller.c @@ -2060,13 +2060,15 @@ static int atmel_nand_controller_init(struct atmel_= nand_controller *nc, nc->mck =3D of_clk_get(dev->parent->of_node, 0); if (IS_ERR(nc->mck)) { dev_err(dev, "Failed to retrieve MCK clk\n"); - return PTR_ERR(nc->mck); + ret =3D PTR_ERR(nc->mck); + goto out_release_dma; } =20 np =3D of_parse_phandle(dev->parent->of_node, "atmel,smc", 0); if (!np) { dev_err(dev, "Missing or invalid atmel,smc property\n"); - return -EINVAL; + ret =3D -EINVAL; + goto out_release_dma; } =20 nc->smc =3D syscon_node_to_regmap(np); @@ -2074,10 +2076,16 @@ static int atmel_nand_controller_init(struct atmel_= nand_controller *nc, if (IS_ERR(nc->smc)) { ret =3D PTR_ERR(nc->smc); dev_err(dev, "Could not get SMC regmap (err =3D %d)\n", ret); - return ret; + goto out_release_dma; } =20 return 0; + +out_release_dma: + if (nc->dmac) + dma_release_channel(nc->dmac); + + return ret; } =20 static int --=20 2.25.1