From nobody Fri May 8 06:01:29 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 6CEC1C433EF for ; Tue, 10 May 2022 08:08:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237818AbiEJIMP (ORCPT ); Tue, 10 May 2022 04:12:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39600 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237893AbiEJILD (ORCPT ); Tue, 10 May 2022 04:11:03 -0400 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23A1772207 for ; Tue, 10 May 2022 01:07:01 -0700 (PDT) Received: from kwepemi100006.china.huawei.com (unknown [172.30.72.54]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4Ky9bf1mymzhZ16; Tue, 10 May 2022 16:06:22 +0800 (CST) Received: from kwepemm600014.china.huawei.com (7.193.23.54) by kwepemi100006.china.huawei.com (7.221.188.165) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 10 May 2022 16:06:59 +0800 Received: from ubuntu1804.huawei.com (10.67.175.28) by kwepemm600014.china.huawei.com (7.193.23.54) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Tue, 10 May 2022 16:06:59 +0800 From: Yi Yang To: , , CC: , , , Subject: [PATCH -next] xtensa/simdisk: fix error handling in proc_read_simdisk() Date: Tue, 10 May 2022 16:05:33 +0800 Message-ID: <20220510080533.51032-1-yiyang13@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 X-Originating-IP: [10.67.175.28] X-ClientProxiedBy: dggems704-chm.china.huawei.com (10.3.19.181) To kwepemm600014.china.huawei.com (7.193.23.54) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The frist simple_read_from_buffer() will change ppos. if ppos >=3D 1. The second simple_read_from_buffer() will does not work and return 0. Fixes: a69755b18774 ("xtensa simdisk: switch to proc_create_data()") Signed-off-by: Yi Yang Reported-by: kernel test robot --- arch/xtensa/platforms/iss/simdisk.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-) diff --git a/arch/xtensa/platforms/iss/simdisk.c b/arch/xtensa/platforms/is= s/simdisk.c index 0f0e0724397f..618c080c388d 100644 --- a/arch/xtensa/platforms/iss/simdisk.c +++ b/arch/xtensa/platforms/iss/simdisk.c @@ -210,13 +210,21 @@ static ssize_t proc_read_simdisk(struct file *file, c= har __user *buf, { struct simdisk *dev =3D pde_data(file_inode(file)); const char *s =3D dev->filename; + char *temp; + if (s) { + ssize_t len =3D strlen(s); + + temp =3D kmalloc(len + 2, GFP_KERNEL); + if (!temp) + return -ENOMEM; + + scnprintf(temp, len + 2, "%s\n", s); ssize_t n =3D simple_read_from_buffer(buf, size, ppos, - s, strlen(s)); - if (n < 0) - return n; - buf +=3D n; - size -=3D n; + temp, strlen(temp)); + + kfree(temp); + return n; } return simple_read_from_buffer(buf, size, ppos, "\n", 1); } --=20 2.17.1